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Konovalov IB, Golovushkin NA, Beekmann M. Wildfire-smoke-precipitation interactions in Siberia: Insights from a regional model study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 951:175518. [PMID: 39151635 DOI: 10.1016/j.scitotenv.2024.175518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 07/24/2024] [Accepted: 08/12/2024] [Indexed: 08/19/2024]
Abstract
Powerful wildfires occurring in Siberia each summer emit large amounts of smoke aerosol that, according to studies of the environmental impacts of biomass burning (BB) aerosol in different regions of the world, can affect precipitation and other weather parameters and induce feedback on fires. However, the knowledge of smoke-weather interactions and fire-weather feedback in Siberia is presently limited. To advance this knowledge, we performed coupled-meteorology-chemistry simulations of aerosols and weather in a Siberian region covering taiga and tundra using the CHIMERE chemistry-transport model and the WRF meteorological model. We addressed a monthly period of July 2016 and considered several modeling scenarios in which aerosol-radiation interaction (ARI) and aerosol-cloud interaction (ACI) were taken into account jointly or separately. The simulation results were combined with emission and precipitation data retrieved from satellite observations. The joint analysis of the simulated precipitation fields and satellite-observation-based data revealed that in the taiga, the inhibiting effect of Siberian smoke on precipitation induced a significant positive feedback on BB aerosol emissions that, according to our estimates, enhanced by 27 (±7) % respective to a hypothetical situation in which smoke-weather interactions were absent. At the same time, an increase of precipitation over active fire spots due to ACI and ARI in tundra led to the formation of a negative feedback loop between fire emissions and BB smoke, resulting in a reduction of BB aerosol emissions there by 14 (±6) %. Hence, this study revealed evidence for significant feedback of smoke-induced precipitation changes on fire emissions in Siberia. Given the global importance of Siberia as a major carbon sink, this feedback needs to be studied further and accurately taken into account in projections of climate change both on regional and global scales.
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Affiliation(s)
- Igor B Konovalov
- A.V. Gaponov-Grekhov Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia.
| | - Nikolai A Golovushkin
- A.V. Gaponov-Grekhov Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Matthias Beekmann
- Université Paris Cité and Univ Paris Est Creteil, CNRS, LISA, F-75013 Paris, France
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2
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Ge P, Zhang Y, Fan S, Wang Y, Wu H, Wang X, Zhang S. Observational study of microphysical and chemical characteristics of size-resolved fog in different regional backgrounds in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175329. [PMID: 39122025 DOI: 10.1016/j.scitotenv.2024.175329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 07/29/2024] [Accepted: 08/04/2024] [Indexed: 08/12/2024]
Abstract
To investigate the relationship between microphysical and chemical characteristics of size-resolved fog droplets in different regional backgrounds, we conducted observational experiments in urban, mountainous, rainforest, and rural areas of China. Fog water samples across different diameter ranges (4-16 μm, 16-22 μm, and >22 μm) were collected, alongside fog droplet spectra data. Our findings reveal a close relationship between pH value, electrical conductivity (EC), total ion concentration (TIC) of droplets, and droplet sizes, with smaller droplets exhibiting stronger acidity and higher ion concentrations. Significant differences in chemical composition are observed across size ranges and regional backgrounds. Droplet number concentration (N) and liquid water content (LWC) distributions in different regional backgrounds are skewed, with peak diameters of LWC spectra similar to those of N spectra, yet overall spectral distributions varied significantly. Droplet number concentrations are highest in urban area, while large droplets contribute more to overall LWC in mountainous, rainforest, and rural areas. No direct evidence linked LWC or surface area (S) to LWC ratio to water-soluble ion concentrations of size-resolved fog droplets in different regional backgrounds. However, by adjusting the contributions of S and LWC proportions of different-sized droplets to the ion concentration proportions, we find that expanding the LWC proportion to 2.43 times and decreasing the S proportion to 0.2 times for large droplets, while decreasing the LWC ratio to 0.76 times for small droplets, provided a better explanation for the distribution of ion concentrations. This study advances our understanding of the intricate relationship between the microphysical and chemical characteristics of fog, helping to develop more robust and comprehensive models for fog prediction and management.
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Affiliation(s)
- Panyan Ge
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology (NUIST), Nanjing 210044, China; College of Meteorology and Oceanography, National University of Defense Technology, Changsha 410073, China; High Impact Weather Key Laboratory of CMA, Changsha 410073, China
| | - Yun Zhang
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology (NUIST), Nanjing 210044, China; College of Meteorology and Oceanography, National University of Defense Technology, Changsha 410073, China; High Impact Weather Key Laboratory of CMA, Changsha 410073, China.
| | - Shuxian Fan
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology (NUIST), Nanjing 210044, China.
| | - Yuan Wang
- Collaborative Innovation Center for Western Ecological Safety, Lanzhou University, Lanzhou 730000, China
| | - Haopeng Wu
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science & Technology (NUIST), Nanjing 210044, China; Department of Atmospheric Science, Yonsei University, Seoul 03722, South Korea
| | - Xinyi Wang
- Key Laboratory for Meteorological Disaster Monitoring and Early Warning and Risk Management of Characteristic Agriculture in Arid Regions, CMA, China; Ningxia Key Lab of Meteorological Disaster Prevention and Reduction, China
| | - Sirui Zhang
- Meteorological Bureau, Shangrao 334000, China
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Zhao C, Sun Y, Yang J, Li J, Zhou Y, Yang Y, Fan H, Zhao X. Observational evidence and mechanisms of aerosol effects on precipitation. Sci Bull (Beijing) 2024; 69:1569-1580. [PMID: 38503650 DOI: 10.1016/j.scib.2024.03.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 02/19/2024] [Accepted: 02/20/2024] [Indexed: 03/21/2024]
Abstract
Aerosols greatly influence precipitation characteristics, thereby impacting the regional climate and human life. As an indispensable factor for cloud formation and a critical radiation budget regulator, aerosols can affect precipitation intensity, frequency, geographical distribution, area, and time. However, discrepancies exist among current studies due to aerosol properties, precipitation types, the vertical location of aerosols and meteorological conditions. The development of technology has driven advances in current research, but understanding the aerosol effects on precipitation remain complex and challenging. This paper revolves around the following topics from the two perspectives of Aerosol-Radiation Interaction (ARI) and Aerosol-Cloud Interaction (ACI): (1) the influence of different vertical locations of absorbing/scattering aerosols on the atmospheric thermal structure; (2) the fundamental theories of ARI reducing surface wind speed, redistributing water vapour and energy, and then modulating precipitation intensity; (3) different aerosol types (absorbing versus scattering) and aerosol concentrations causing different precipitation diurnal and weekly variations; (4) microphysical processes (cloud water competition, invigoration effect, and evaporation cooling) and observational evidence of different effects of aerosols on precipitation intensity, including enhancing, inhibiting, and transitional effects from enhancement to suppression; and (5) how meteorology, water vapor and dynamics influencing the effect of ACI and ARI on precipitation. In addition, this review lists the existing issues and future research directions for attaining a more comprehensive understanding of aerosol effects on precipitation. Overall, this review advances our understanding of aerosol effects on precipitation and could guide the improvement of weather and climate models to predict complex aerosol-precipitation interactions more accurately.
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Affiliation(s)
- Chuanfeng Zhao
- Department of Atmospheric and Oceanic Sciences, School of Physics, and China Meteorological Administration Tornado Key Laboratory, Peking University, Beijing 100871, China; Institute of Carbon Neutrality, Peking University, Beijing 100871, China.
| | - Yue Sun
- Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Jie Yang
- Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Jiefeng Li
- Department of Atmospheric and Oceanic Sciences, School of Physics, and China Meteorological Administration Tornado Key Laboratory, Peking University, Beijing 100871, China
| | - Yue Zhou
- Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
| | - Yikun Yang
- Department of Atmospheric and Oceanic Sciences, School of Physics, and China Meteorological Administration Tornado Key Laboratory, Peking University, Beijing 100871, China
| | - Hao Fan
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Xin Zhao
- Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
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Ferrero L, Losi N, Rigler M, Gregorič A, Colombi C, D'Angelo L, Cuccia E, Cefalì AM, Gini I, Doldi A, Cerri S, Maroni P, Cipriano D, Markuszewski P, Bolzacchini E. Determining the Aethalometer multiple scattering enhancement factor C from the filter loading parameter. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170221. [PMID: 38280585 DOI: 10.1016/j.scitotenv.2024.170221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/27/2023] [Accepted: 01/14/2024] [Indexed: 01/29/2024]
Abstract
Light-absorbing aerosols heat the atmosphere; an accurate quantification of their absorption coefficient is mandatory. However, standard reference instruments (CAPS, MAAP, PAX, PTAAM) are not always available at each measuring site around the world. By integrating all previous published studies concerning the Aethalometers, the AE33 filter loading parameter, provided by the dual-spot algorithm, were used to determine the multiple scattering enhancement factor from the Aethalometer itself (hereinafter CAE) on an yearly and a monthly basis. The method was developed in Milan, where Aethalometer measurements were compared with MAAP data; the comparison showed a good agreement in terms of equivalent black carbon (R2 = 0.93; slope = 1.02 and a negligible intercept = 0.12 μg m-3) leading to a yearly experimental multiple scattering enhancement factor of 2.51 ± 0.04 (hereinafter CMAAP). On a yearly time base the CAE values obtained using the new approach was 2.52 ± 0.01, corresponding to the experimental one (CMAAP). Considering the seasonal behavior, higher experimental CMAAP and computed CAE values were found in summer (2.83 ± 0.12) whereas, the lower ones in winter/early-spring (2.37 ± 0.03), in agreement with the single scattering albedo behavior in the Po Valley. Overall, the agreement between the experimental CMAAP and CAE showed a root mean squared error (RMSE) of just 0.038 on the CMAAP prediction, characterized by a slope close to 1 (1.001 ± 0.178), a negligible intercept (-0.002 ± 0.455) and a high degree of correlation (R2 = 0.955). From an environmental point of view, the application of a dynamic (space/time) determination of CAE increases the accuracy of the aerosol heating rate (compared to applying a fixed C value) up to 16 % solely in Milan, and to 114 % when applied in the Arctic at 80°N.
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Affiliation(s)
- L Ferrero
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy.
| | - N Losi
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - M Rigler
- Aerosol d.o.o., Kamniška 39A, SI-1000 Ljubljana, Slovenia
| | - A Gregorič
- Aerosol d.o.o., Kamniška 39A, SI-1000 Ljubljana, Slovenia; Center for Atmospheric Research, University of Nova Gorica, SI-5000 Nova Gorica, Slovenia
| | - C Colombi
- Regional Agency for Environmental Protection of Lombardy (ARPA Lombardia), Air Quality Department, Milan, Italy
| | - L D'Angelo
- Regional Agency for Environmental Protection of Lombardy (ARPA Lombardia), Air Quality Department, Milan, Italy; Institute for Atmospheric and Environmental Sciences, Goethe-University Frankfurt, Frankfurt am Main 60438, Germany
| | - E Cuccia
- Regional Agency for Environmental Protection of Lombardy (ARPA Lombardia), Air Quality Department, Milan, Italy
| | - A M Cefalì
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy; RSE - Ricerca sul Sistema Energetico S.p.A., via Rubattino 54, 20134 Milano, Italy
| | - I Gini
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - A Doldi
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - S Cerri
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - P Maroni
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - D Cipriano
- RSE - Ricerca sul Sistema Energetico S.p.A., via Rubattino 54, 20134 Milano, Italy
| | - P Markuszewski
- Institute of Oceanology, Polish Academy of Sciences, 81-712 Sopot, Poland; Bolin Centre for Climate Research and Department of Environmental Science, Stockholm University, 10691 Stockholm, Sweden
| | - E Bolzacchini
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
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Sharma A, Srivastava S, Mitra D, Singh RP. Spatiotemporal distribution of air pollutants during a heat wave-induced forest fire event in Uttarakhand. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:110133-110160. [PMID: 37779123 DOI: 10.1007/s11356-023-29906-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 09/12/2023] [Indexed: 10/03/2023]
Abstract
Prevailing dry conditions and rainfall deficit during the spring season in North India led to heat wave conditions which resulted in widespread and intense forest fire events in the Himalayan state of Uttarakhand during April 16-30, 2022. A total of 7589 active fires were detected by VIIRS during the second half of April 2022 compared to 1558 during the first half. The TROPOMI observed total column values of CO and NO2 increased by 4.4% and 11.7%, respectively during April 16-30, 2022 with respect to April 1-15, 2022. A noticeable increase in surface level concentration of trace gases was also observed at Dehradun. In situ measurements of CO, NOx, and O3 during April 16-30, 2022 show an increase of 133, 35, and 6% compared to previous year observations during the same period. Weather Research and Forecasting model with chemistry (WRF-Chem) is utilized to quantitatively estimate the contribution of this event on the distribution of air pollutants over this state. The model results were evaluated against ERA5 reanalysis, upper air soundings, and TROPOMI-retrieved total column density (TCD) of CO, NO2, and O3. Two simulations with (Fire) and without (NoFire) biomass burning emissions input were performed to quantify the contribution of forest fires to the concentration of trace gases and particulates. The CO, NO2, and O3 emitted/produced from forest fire over Uttarakhand during April 2022 contributed approximately 39.95, 35.73, and 9.97% to the surface concentration of respective gas. In the case of aerosols, it was around 71.20, 71.44, and 33.62% for PM2.5, PM10, and BC respectively. The vertical profile analysis of pollutants revealed that extreme forest fire events can perturb the distribution of air pollutants from the surface up to 450 hPa.
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6
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Jo DS, Nault BA, Tilmes S, Gettelman A, McCluskey CS, Hodzic A, Henze DK, Nawaz MO, Fung KM, Jimenez JL. Global Health and Climate Effects of Organic Aerosols from Different Sources. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:13793-13807. [PMID: 37671787 DOI: 10.1021/acs.est.3c02823] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
The impact of aerosols on human health and climate is well-recognized, yet many studies have only focused on total PM2.5 or changes from anthropogenic activities. This study quantifies the health and climate effects of organic aerosols (OA) from anthropogenic, biomass burning, and biogenic sources. Using two atmospheric chemistry models, CAM-chem and GEOS-Chem, our findings reveal that anthropogenic primary OA (POA) has the highest efficiency for health effects but the lowest for direct radiative effects due to spatial and temporal variations associated with population and surface albedo. The treatment of POA as nonvolatile or semivolatile also influences these efficiencies through different chemical processes. Biogenic OA shows moderate efficiency for health effects and the highest for direct radiative effects but has the lowest efficiency for indirect effects due to the reduced high cloud, caused by stabilized temperature profiles from aerosol-radiation interactions in biogenic OA-rich regions. Biomass burning OA is important for cloud radiative effect changes in remote atmospheres due to its ability to be transported further than other OAs. This study highlights the importance of not only OA characteristics such as toxicity and refractive index but also atmospheric processes such as transport and chemistry in determining health and climate impact efficiencies.
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Affiliation(s)
- Duseong S Jo
- Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80301, United States
| | - Benjamin A Nault
- Center for Aerosols and Cloud Chemistry, Aerodyne Research, Inc., Billerica, Massachusetts 01821, United States
- Department of Environmental Health and Engineering, The Johns Hopkins University, Baltimore, Maryland 21205, United States
| | - Simone Tilmes
- Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80301, United States
| | - Andrew Gettelman
- Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80301, United States
- Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80305, United States
| | - Christina S McCluskey
- Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80305, United States
| | - Alma Hodzic
- Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder, Colorado 80301, United States
| | - Daven K Henze
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Muhammad Omar Nawaz
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Ka Ming Fung
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Jose L Jimenez
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States
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7
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Climatic–Environmental Effects of Aerosols and Their Sensitivity to Aerosol Mixing States in East Asia in Winter. REMOTE SENSING 2022. [DOI: 10.3390/rs14153539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
To establish the direct climatic and environmental effect of anthropogenic aerosols in East Asia in winter under external, internal, and partial internal mixing (EM, IM and PIM) states, a well-developed regional climate–chemical model RegCCMS is used by carrying out sensitive numerical simulations. Different aerosol mixing states yield different aerosol optical and radiative properties. The regional averaged EM aerosol single scattering albedo is approximately 1.4 times that of IM. The average aerosol effective radiative forcing in the atmosphere ranges from −0.35 to +1.40 W/m2 with increasing internal mixed aerosols. Due to the absorption of black carbon aerosol, lower air temperatures are increased, which likely weakens the EAWM circulations and makes the atmospheric boundary more stable. Consequently, substantial accumulations of aerosols further appear in most regions of China. This type of interaction will be intensified when more aerosols are internally mixed. Overall, the aerosol mixing states may be important for regional air pollution and climate change assessments. The different aerosol mixing states in East Asia in winter will result in a variation from 0.04 to 0.11 K for the averaged lower air temperature anomaly and from approximately 0.45 to 2.98 μg/m3 for the aerosol loading anomaly, respectively, due to the different mixing aerosols.
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Anthropogenic Aerosols Effects on Ice Clouds: A Review. ATMOSPHERE 2022. [DOI: 10.3390/atmos13060910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Since the ability of anthropogenic aerosols to act as ice nucleation particles has been recognized, the effect of anthropogenic aerosols on ice clouds has attracted increasing attentions. In recent years, some progress has been made in investigating the effects of anthropogenic aerosols on ice clouds. In this paper, we briefly review the study on the impact of anthropogenic aerosols on ice nuclei, properties and radiative forcing of ice clouds. Anthropogenic aerosols can form ice nuclei through homogeneous nucleation and heterogeneous nucleation. Convective strength can modulate the response of ice clouds to anthropogenic aerosols by affecting the nucleation activities. There have been large uncertainties in calculating the radiative forcing of anthropogenic aerosols on ice clouds in climate models. Further studies on the impact of anthropogenic aerosols on ice clouds are imperative to provide better parameterization schemes and reduce the uncertainties of aerosol indirect effects.
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Jnanesh SP, Lal DM, Gopalakrishnan V, Ghude SD, Pawar SD, Tiwari S, Srivastava MK. Lightning Characteristics Over Humid Regions and Arid Regions and Their Association With Aerosols Over Northern India. PURE AND APPLIED GEOPHYSICS 2022; 179:1403-1419. [PMID: 35250099 PMCID: PMC8883017 DOI: 10.1007/s00024-022-02981-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 02/10/2022] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
UNLABELLED The association between aerosol and lightning has been investigated with long-term decadal data (2005-2014) for lightning, aerosol optical depth (AOD), relative humidity, and effective cloud droplet size. To understand the complex relationship between aerosol and lightning, two different regions with different climatic and weather conditions, a humid region R1 (22°-29° N, 89°-92° E) and an arid region R2 (23°-28° N, 70°-76° E) of northern India, were chosen for the study domain. The results show that lightning activity was observed to occur more over the humid region R1, i.e., 1141 days (1/3 of total days), than over the arid region R2, i.e., 740 days (1/5 of total days). Also, over the humid region R1, the highest lightning flash density was recorded as nearly 4.6 × 10-4 flashes/km2/day observed for 18 days (1.5%); on the contrary, over the arid region R2, the maximum lightning flash density was observed to be 2.5 × 10-4 flashes/km2/day and occurred for about 22 days (2.9%). The analysis shows that a nonlinear relationship exists between aerosol and lightning with a highly associated influence of relative humidity. A very significant positive and negative co-relation that varies with relative humidity has been observed between AOD and lightning for both humid and arid regions. This shows relative humidity is the key factor in determining the increase or decrease of lightning activity. This study also shows that the larger the cloud droplet size, the higher the relative humidity and vice versa. This study emphasizes that aerosol concentration in the atmosphere influences cloud microphysics by modulating the size of cloud droplets and thereby regulating the lightning frequency. The atmospheric humidity is the driving factor in deciding the positive or negative co-relationship between aerosol and lightning. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s00024-022-02981-6.
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Affiliation(s)
- S. P. Jnanesh
- Indian Institute of Tropical Meteorology, Pune, India
- Department of Geophysics, Banaras Hindu University, Varanasi, India
| | - D. M. Lal
- Indian Institute of Tropical Meteorology, Pune, India
| | | | | | | | - S. Tiwari
- Indian Institute of Tropical Meteorology, Pune, India
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10
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Beal A, Martins JA, Rudke AP, de Almeida DS, da Silva I, Sobrinho OM, de Fátima Andrade M, Tarley CRT, Martins LD. Chemical characterization of PM 2.5 from region highly impacted by hailstorms in South America. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:5840-5851. [PMID: 34431047 DOI: 10.1007/s11356-021-15952-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
The chemical composition of particulate material plays an important role in the atmosphere, providing cloud and ice nuclei for storm development. This study aims to evaluate and infer the sources of ions, metals, and metalloids in the fine atmospheric particulate matter (PM2.5) from triple border Paraná, Santa Catarina (Brazil), and northeastern Argentina, which is among those with the highest hail incidence in the world. Among the ions, the concentrations presented the following sequence in decreasing order: [Formula: see text]> K+> [Formula: see text]> [Formula: see text]> Ca2+> Cl-> Na+> Mg2+. Regarding the metals and metalloid concentrations, the order was of S > Si > Al > Fe > P > Ti, Cr, Cu, and Zn > Br > Mn, and Ni. The main sources, supported by positive matrix factorization results, are soil and agricultural activities, as well as vehicular emissions due to the agricultural machinery and the displacement of residents. Besides, the influence of aerosols from biomass burning and industrial activities was observed, possibly come from long-distance transport. The composition of PM2.5 presents one or more elements considered present ice nuclei (IN) activity, such as Al, Mn, Cu, Co, Ni, and V (in form of oxides), corroborating with other studies, also, with high hail incidence. However, further studies are needed to verify the role of aerosol characteristics in the formation of IN and, consequently, hail.
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Affiliation(s)
- Alexandra Beal
- Universidade Estadual de Londrina, Rodovia Celso Garcia Cid 445 km 380, Londrina, PR, 86057-970, Brazil.
- Federal University of Technology - Paraná, Av. dos Pioneiros, 3131, Londrina, PR, 86036-370, Brazil.
| | - Jorge A Martins
- Federal University of Technology - Paraná, Av. dos Pioneiros, 3131, Londrina, PR, 86036-370, Brazil
| | - Anderson P Rudke
- Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, Belo Horizonte, MG, 31270-901, Brazil
| | - Daniela S de Almeida
- Federal University of São Carlos, Rod. Washington Luiz, Km 235, SP310, São Carlos, SP, 13565-905, Brazil
| | - Iara da Silva
- Federal University of Technology - Paraná, Av. dos Pioneiros, 3131, Londrina, PR, 86036-370, Brazil
- Department of Atmospheric Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Otavio Medeiros Sobrinho
- Federal University of Technology - Paraná, Av. dos Pioneiros, 3131, Londrina, PR, 86036-370, Brazil
| | | | - César R T Tarley
- Universidade Estadual de Londrina, Rodovia Celso Garcia Cid 445 km 380, Londrina, PR, 86057-970, Brazil
- Departamento de Química Analítica, Instituto de Química, Instituto Nacional de Ciência e Tecnologia (INCT) de Bioanalítica, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, 13083-970, Brazil
| | - Leila D Martins
- Federal University of Technology - Paraná, Av. dos Pioneiros, 3131, Londrina, PR, 86036-370, Brazil
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11
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Ding K, Huang X, Ding A, Wang M, Su H, Kerminen VM, Petäjä T, Tan Z, Wang Z, Zhou D, Sun J, Liao H, Wang H, Carslaw K, Wood R, Zuidema P, Rosenfeld D, Kulmala M, Fu C, Pöschl U, Cheng Y, Andreae MO. Aerosol-boundary-layer-monsoon interactions amplify semi-direct effect of biomass smoke on low cloud formation in Southeast Asia. Nat Commun 2021; 12:6416. [PMID: 34741045 PMCID: PMC8571318 DOI: 10.1038/s41467-021-26728-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 10/13/2021] [Indexed: 11/23/2022] Open
Abstract
Low clouds play a key role in the Earth-atmosphere energy balance and influence agricultural production and solar-power generation. Smoke aloft has been found to enhance marine stratocumulus through aerosol-cloud interactions, but its role in regions with strong human activities and complex monsoon circulation remains unclear. Here we show that biomass burning aerosols aloft strongly increase the low cloud coverage over both land and ocean in subtropical southeastern Asia. The degree of this enhancement and its spatial extent are comparable to that in the Southeast Atlantic, even though the total biomass burning emissions in Southeast Asia are only one-fifth of those in Southern Africa. We find that a synergetic effect of aerosol-cloud-boundary layer interaction with the monsoon is the main reason for the strong semi-direct effect and enhanced low cloud formation in southeastern Asia.
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Affiliation(s)
- Ke Ding
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- Jiangsu Provincial Collaborative Innovation Center of Climate Change, Nanjing, China
- Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing, 210023, China
| | - Xin Huang
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- Jiangsu Provincial Collaborative Innovation Center of Climate Change, Nanjing, China
- Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing, 210023, China
| | - Aijun Ding
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China.
- Jiangsu Provincial Collaborative Innovation Center of Climate Change, Nanjing, China.
- Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing, 210023, China.
| | - Minghuai Wang
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- Jiangsu Provincial Collaborative Innovation Center of Climate Change, Nanjing, China
| | - Hang Su
- Max Planck Institute for Chemistry, Mainz, Germany
| | - Veli-Matti Kerminen
- Institute for Atmospheric and Earth System Research (INAR)/Physics, University of Helsinki, Helsinki, Finland
| | - Tuukka Petäjä
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- Institute for Atmospheric and Earth System Research (INAR)/Physics, University of Helsinki, Helsinki, Finland
| | - Zhemin Tan
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- Jiangsu Provincial Collaborative Innovation Center of Climate Change, Nanjing, China
| | - Zilin Wang
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
| | - Derong Zhou
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- Jiangsu Provincial Collaborative Innovation Center of Climate Change, Nanjing, China
| | - Jianning Sun
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- Jiangsu Provincial Collaborative Innovation Center of Climate Change, Nanjing, China
| | - Hong Liao
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing, 210044, China
| | - Huijun Wang
- School of Atmospheric Sciences, Nanjing University of Information and Science Technology, Nanjing, 210044, China
| | - Ken Carslaw
- Institute for Climate and Atmospheric Science, School of Earth and Environment, University of Leeds, Leeds, UK
| | - Robert Wood
- Department of Atmospheric Sciences, University of Washington, Seattle, USA
| | - Paquita Zuidema
- Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Miami, FL, USA
| | - Daniel Rosenfeld
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Markku Kulmala
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- Institute for Atmospheric and Earth System Research (INAR)/Physics, University of Helsinki, Helsinki, Finland
| | - Congbin Fu
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- Jiangsu Provincial Collaborative Innovation Center of Climate Change, Nanjing, China
| | | | - Yafang Cheng
- Max Planck Institute for Chemistry, Mainz, Germany.
| | - Meinrat O Andreae
- Max Planck Institute for Chemistry, Mainz, Germany
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
- Department of Geology and Geophysics, King Saud University, Riyadh, Saudi Arabia
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12
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Ma S, Shao M, Zhang Y, Dai Q, Xie M. Sensitivity of PM 2.5 and O 3 pollution episodes to meteorological factors over the North China Plain. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 792:148474. [PMID: 34153765 DOI: 10.1016/j.scitotenv.2021.148474] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 05/28/2021] [Accepted: 06/11/2021] [Indexed: 06/13/2023]
Abstract
The Comprehensive Air-quality Model with extensions (CAMx) was used to explore the sensitivity of PM2.5 and O3 concentrations to four selected meteorological factors: wind speed, temperature, water vapor mixing ratio (Q), and planetary boundary layer height (PBLH) during two pollution episodes over the North China Plain (NCP). We also investigated the impact pathways of different meteorological factors on the formation of PM2.5 and O3. It is found that PM2.5 was more sensitive to the selected meteorological factors in the southeastern NCP, where high anthropogenic emissions and severe air pollution occur. Large variations were observed along the Taihang Mountains, where the height of the terrain changes dramatically. The sensitivity of O3 to wind speed, PBLH, temperature, and Q was mainly determined by the inhibition effects of PM2.5 in winter, while in summer, the complex chemical reactions were dominant. Significant diurnal variations of process analysis (PA) results were observed under various meteorological conditions. Higher temperature generally enhance heterogeneous chemistry and transport of NO3- through the top boundary layer during night-time in winter, however, in summer, the heterogeneous chemistry of NO3- and NH4+ during daytime were the major pathways to the increased PM2.5 due to increased temperature. Moreover, temperature alter PM2.5 concentrations through affecting vertical diffusivity and relative humidity, and alter O3 concentrations by affecting the gas phase chemistry and mass fluxes through the top boundary layer. Q mainly affects the rate of chemical reactions of PM2.5 and O3. The different impact pathways suggest that it is essential to consider variations in meteorological factors, in addition to the direct impacts of wind speed and PBLH, more attention should be paid to the complex impacts of temperature and Q, when developing emission control strategies.
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Affiliation(s)
- Simeng Ma
- Nankai Univ, Coll Environm Sci & Engn, State Environm Protect Key Lab Urban Ambient Air, Tianjin 300071, China
| | - Min Shao
- School of Environment, Nanjing Normal University, Nanjing 210023, China.
| | - Yufen Zhang
- Nankai Univ, Coll Environm Sci & Engn, State Environm Protect Key Lab Urban Ambient Air, Tianjin 300071, China
| | - Qili Dai
- Nankai Univ, Coll Environm Sci & Engn, State Environm Protect Key Lab Urban Ambient Air, Tianjin 300071, China
| | - Mingjie Xie
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China
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13
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Ferrero L, Bernardoni V, Santagostini L, Cogliati S, Soldan F, Valentini S, Massabò D, Močnik G, Gregorič A, Rigler M, Prati P, Bigogno A, Losi N, Valli G, Vecchi R, Bolzacchini E. Consistent determination of the heating rate of light-absorbing aerosol using wavelength- and time-dependent Aethalometer multiple-scattering correction. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 791:148277. [PMID: 34119780 DOI: 10.1016/j.scitotenv.2021.148277] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 05/17/2021] [Accepted: 06/02/2021] [Indexed: 06/12/2023]
Abstract
Accurate and temporally consistent measurements of light absorbing aerosol (LAA) heating rate (HR) and of its source apportionment (fossil-fuel, FF; biomass-burning, BB) and speciation (black and brown Carbon; BC, BrC) are needed to evaluate LAA short-term climate forcing. For this purpose, wavelength- and time-dependent accurate LAA absorption coefficients are required. HR was experimentally determined and apportioned (sources/species) in the EMEP/ACTRIS/COLOSSAL-2018 winter campaign in Milan (urban-background site). Two Aethalometers (AE31/AE33) were installed together with a MAAP, CPC, OPC, a low volume sampler (PM2.5) and radiation instruments. AE31/AE33 multiple-scattering correction factors (C) were determined using two reference systems for the absorption coefficient: 1) 5-wavelength PP_UniMI with low time resolution (12 h, applied to PM2.5 samples); 2) timely-resolved MAAP data at a single wavelength. Using wavelength- and time-independent C values for the AE31 and AE33 obtained with the same reference device, the total HR showed a consistency (i.e. reproducibility) with average values comparable at 95% probability. However, if different reference devices/approaches are used, i.e. MAAP is chosen as reference instead of a PP_UniMI, the HR can be overestimated by 23-30% factor (by both AE31/AE33). This became more evident focusing on HR apportionment: AE33 data (corrected by a wavelength- and time-independent C) showed higher HRFF (+24 ± 1%) and higher HRBC (+10 ± 1%) than that of AE31. Conversely, HRBB and HRBrC were -28 ± 1% and -29 ± 1% lower for AE33 compared to AE31. These inconsistencies were overcome by introducing a wavelength-dependent Cλ for both AE31 and AE33, or using multi-wavelength apportionment methods, highlighting the need for further studies on the influence of wavelength corrections for HR determination. Finally, the temporally-resolved determination of C resulted in a diurnal cycle of the HR not statistically different whatever the source- speciation- apportionment used.
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Affiliation(s)
- L Ferrero
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy.
| | - V Bernardoni
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - L Santagostini
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - S Cogliati
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy; Remote Sensing of Environmental Dynamics Lab., DISAT, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano, Italy
| | - F Soldan
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - S Valentini
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - D Massabò
- Dip. di Fisica Università di Genova & INFN Sezione di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - G Močnik
- Center for Atmospheric Research, University of Nova Gorica, SI-5000 Nova Gorica, Slovenia; Department of Condensed Matter Physics, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - A Gregorič
- Center for Atmospheric Research, University of Nova Gorica, SI-5000 Nova Gorica, Slovenia; Aerosol d.o.o., Kamniška 39A, SI-1000 Ljubljana, Slovenia
| | - M Rigler
- Aerosol d.o.o., Kamniška 39A, SI-1000 Ljubljana, Slovenia
| | - P Prati
- Dip. di Fisica Università di Genova & INFN Sezione di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - A Bigogno
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - N Losi
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
| | - G Valli
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - R Vecchi
- Dipartimento di Fisica "A. Pontremoli", Università degli Studi di Milano & INFN-Milan, 20133 Milano, Italy
| | - E Bolzacchini
- GEMMA and POLARIS Centre, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy
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14
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Huang X, Ding A. Aerosol as a critical factor causing forecast biases of air temperature in global numerical weather prediction models. Sci Bull (Beijing) 2021; 66:1917-1924. [PMID: 36654401 DOI: 10.1016/j.scib.2021.05.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 03/13/2021] [Accepted: 03/19/2021] [Indexed: 02/03/2023]
Abstract
Weather prediction is essential to the daily life of human beings. Current numerical weather prediction models such as the Global Forecast System (GFS) are still subject to substantial forecast biases and rarely consider the impact of atmospheric aerosol, despite the consensus that aerosol is one of the most important sources of uncertainty in the climate system. Here we demonstrate that atmospheric aerosol is one of the important drivers biasing daily temperature prediction. By comparing observations and the GFS prediction, we find that the monthly-averaged bias in the 24-h temperature forecast varies between ± 1.5 °C in regions influenced by atmospheric aerosol. The biases depend on the properties of aerosol, the underlying land surface, and aerosol-cloud interactions over oceans. It is also revealed that forecast errors are rapidly magnified over time in regions featuring high aerosol loadings. Our study provides direct "observational" evidence of aerosol's impacts on daily weather forecast, and bridges the gaps between the weather forecast and climate science regarding the understanding of the impact of atmospheric aerosol.
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Affiliation(s)
- Xin Huang
- School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China; Jiangsu Provincial Collaborative Innovation Center of Climate Change, Nanjing 210023, China
| | - Aijun Ding
- School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China; Jiangsu Provincial Collaborative Innovation Center of Climate Change, Nanjing 210023, China.
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15
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Cloud-to-Ground Lightning Response to Aerosol over Air-Polluted Urban Areas in China. REMOTE SENSING 2021. [DOI: 10.3390/rs13132600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The effect of aerosols on lightning has been noted in many studies, but much less is known about the long-term impacts in air-polluted urban areas of China. In this paper, 9-year data sets of cloud-to-ground (CG) lightning, aerosol optical depth (AOD), convective available potential energy (CAPE), and surface relative humidity (SRH) from ground-based observation and model reanalysis are analyzed over three air-polluted urban areas of China. Decreasing trends are found in the interannual variations of CG lightning density (unit: flashes km−2day−1) and total AOD over the three study regions during the study period. An apparent enhancement in CG lightning density is found under conditions with high AOD on the seasonal cycles over the three study regions. The joint effects of total AOD and thermodynamic factors (CAPE and SRH) on CG lightning density and the percentage of positive CG flashes (+CG flashes/total CG flashes × 100; PPCG; unit: %) are further analyzed. Results show that CG lighting density is higher under conditions with high total AOD, while PPCG is lower under conditions with low total AOD. CG lightning density is more sensitive to CAPE under conditions with high total AOD.
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16
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Enhancement of Cloud-to-Ground Lightning Activity Caused by the Urban Effect: A Case Study in the Beijing Metropolitan Area. REMOTE SENSING 2021. [DOI: 10.3390/rs13071228] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
To investigate the possible impact of urban development on lightning activity, an eight-year (2010–2017) cloud-to-ground (CG) lightning dataset provided by the National-Wide Lightning Detection Network in China was analyzed to characterize the CG lightning activity in the metropolitan area of Beijing. There is a high CG flash density area over the downtown of Beijing, but different from previous studies, the downwind area of Beijing is not significantly enhanced. Compared with the upwind area, the CG flash density in the downtown area was enhanced by about 50%. Negative CG flashes mainly occurred in the downtown and industrial area, while positive CG flashes were distributed evenly. The percentage of positive CG flashes with Ipeak ≥ 75 kA is more than six times that of the corresponding negative CG flashes in the Beijing area. The enhancement of lightning activity varies with season and time. About 98% of CG flashes occurred from May to September, and the peak of CG diurnal variation is from 1900 to 2100 local time. Based on the analysis of thunderstorm types in Beijing, it is considered that the abnormal lightning activity is mainly responsible for an enhancement of the discharge number in frontal systems rather than the increase of the number of local thunderstorms. In addition, there is a non-linear relationship between pollutant concentrations and CG flash number, which indicates that there are other critical factors affecting the production of lightning.
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17
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R L, B S M, B S S, Bhanage V, Rathod A, Tiwari A, Beig G, Singh S. Propagation of cloud base to higher levels during Covid-19-Lockdown. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 759:144299. [PMID: 33341515 PMCID: PMC9757895 DOI: 10.1016/j.scitotenv.2020.144299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 06/12/2023]
Abstract
Aerosol-cloud interactions and feedbacks play an important role in modulating cloud development, microphysical and optical properties thus enhancing or reducing precipitation over polluted/pristine regions. The lockdown enforced on account of Covid-19 pandemic is a unique opportunity to verify the influence of drastic reduction in aerosols on cloud development and its vertical distribution embedded in identical synoptic conditions. Cloud bases measured by ceilometer in Delhi, the capital of India, are observed to propagate from low level to higher levels as the lockdown progresses. It is explained in terms of trends in temporal variation of cloud condensation nuclei (CCN) and precursor gases to secondary hygroscopic aerosols. The large reduction (47%) in CCN estimated from aerosol extinction coefficient during the lockdown results in upward shift of cloud bases. Low clouds with bases located below 3 km are found to have reduced significantly from 63% (of total clouds distributed in the vertical) during pre-lockdown to 12% in lockdown period (less polluted). Cloud base height is found to have an inverse correlation with CCN (r = -0.64) and NO2/NH3 concentrations (r = -0.7). The role of meteorology and CCN in modulating the cloud vertical profiles is discussed in terms of anomalies of various controlling factors like lifting condensation level (LCL), precipitable water content (PWC) and mixing layer height (MLH).
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Affiliation(s)
- Latha R
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India
| | - Murthy B S
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India.
| | - Sandeepan B S
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India
| | | | - Aditi Rathod
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India
| | - Arpit Tiwari
- India Meteorological Department, Ministry of Earth Sciences, New Delhi, India
| | - Gufran Beig
- Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India
| | - Siddhartha Singh
- India Meteorological Department, Ministry of Earth Sciences, New Delhi, India
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18
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Fortunato Dos Santos Oliveira DC, Montilla-Rosero E, da Silva Lopes FJ, Morais FG, Landulfo E, Hoelzemann JJ. Aerosol properties in the atmosphere of Natal/Brazil measured by an AERONET Sun-photometer. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:9806-9823. [PMID: 33159225 DOI: 10.1007/s11356-020-11373-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/21/2020] [Indexed: 06/11/2023]
Abstract
We analyzed data measured by a Sun-photometer of the RIMA-AERONET network with the purpose to characterize the aerosol properties in the atmosphere over Natal, state capital of Rio Grande do Norte, at the coast of Northeast Brazil. Aerosol Optical Depth, Ångström Exponent, Volume Size Distribution, Single Scattering Albedo, Complex Refractive Index, Asymmetry Factor, and Precipitable Water were analyzed from August 2017 to March 2018. In addition, MODIS and CALIOP observations, local Lidar measurements, and modeled backward trajectories were analyzed in a case study on February 9, 2018, that consistently confirmed the identification of a persistent aerosol layer below 4 km agl. Aerosols present in the atmosphere of Natal showed monthly mean Aerosol Optical Depth at 500 nm below 0.15 (~ 75%), monthly means of the Ångström Exponent at 440-670 nm between 0.30 and 0.70 (~ 69%), bimodal Volume Size Distribution is dominantly coarse mode, Single Scattering Albedo at 440 nm is 0.80, Refractive Index - Real Part around 1.50, Refractive Index - Imaginary Part ranging from 0.01 to 0.04, and the Asymmetry Factor ranged from 0.73 to 0.80. The aerosol typing during the measurement period showed that atmospheric aerosol over Natal is mostly composed of mixed aerosol (58.10%), marine aerosol (34.80%), mineral dust (6.30%), and biomass burning aerosols (0.80%). Backward trajectories identified that 51% of the analyzed air masses over Natal originated from the African continent.
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Affiliation(s)
| | - Elena Montilla-Rosero
- Physical Sciences Department, School of Science, EAFIT University, Medellín, Colombia
| | - Fábio Juliano da Silva Lopes
- Environmental Science Department, Institute of Environmental, Chemical and Pharmaceutical Science, Federal University of São Paulo - UNIFESP, Rua São Nicolau, 210, Centro, 09913-030, Diadema, São Paulo, Brazil
- Center for Lasers and Applications, Nuclear and Energy Research Institute-IPEN, Av. Prof. Lineu Prestes, 2242, Cidade Universitária, São Paulo, São Paulo, 05508-000, Brazil
| | - Fernando Gonçalves Morais
- Center for Lasers and Applications, Nuclear and Energy Research Institute-IPEN, Av. Prof. Lineu Prestes, 2242, Cidade Universitária, São Paulo, São Paulo, 05508-000, Brazil
- Physics Institute, University of São Paulo - USP, Rua do Matao, 1371, 05508-090, Sao Paulo, SP, Brazil
| | - Eduardo Landulfo
- Center for Lasers and Applications, Nuclear and Energy Research Institute-IPEN, Av. Prof. Lineu Prestes, 2242, Cidade Universitária, São Paulo, São Paulo, 05508-000, Brazil
| | - Judith Johanna Hoelzemann
- Department of Atmospheric and Climate Sciences (UFRN/DCAC), Federal University of Rio Grande do Norte, Natal, Brazil.
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19
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The Dark Target Algorithm for Observing the Global Aerosol System: Past, Present, and Future. REMOTE SENSING 2020. [DOI: 10.3390/rs12182900] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The Dark Target aerosol algorithm was developed to exploit the information content available from the observations of Moderate-Resolution Imaging Spectroradiometers (MODIS), to better characterize the global aerosol system. The algorithm is based on measurements of the light scattered by aerosols toward a space-borne sensor against the backdrop of relatively dark Earth scenes, thus giving rise to the name “Dark Target”. Development required nearly a decade of research that included application of MODIS airborne simulators to provide test beds for proto-algorithms and analysis of existing data to form realistic assumptions to constrain surface reflectance and aerosol optical properties. This research in itself played a significant role in expanding our understanding of aerosol properties, even before Terra MODIS launch. Contributing to that understanding were the observations and retrievals of the growing Aerosol Robotic Network (AERONET) of sun-sky radiometers, which has walked hand-in-hand with MODIS and the development of other aerosol algorithms, providing validation of the satellite-retrieved products after launch. The MODIS Dark Target products prompted advances in Earth science and applications across subdisciplines such as climate, transport of aerosols, air quality, and data assimilation systems. Then, as the Terra and Aqua MODIS sensors aged, the challenge was to monitor the effects of calibration drifts on the aerosol products and to differentiate physical trends in the aerosol system from artefacts introduced by instrument characterization. Our intention is to continue to adapt and apply the well-vetted Dark Target algorithms to new instruments, including both polar-orbiting and geosynchronous sensors. The goal is to produce an uninterrupted time series of an aerosol climate data record that begins at the dawn of the 21st century and continues indefinitely into the future.
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20
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Takeishi A, Storelvmo T, Fierce L. Disentangling the Microphysical Effects of Fire Particles on Convective Clouds Through A Case Study. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2020; 125:e2019JD031890. [PMID: 32714719 PMCID: PMC7379315 DOI: 10.1029/2019jd031890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 03/17/2020] [Accepted: 04/11/2020] [Indexed: 06/11/2023]
Abstract
Aerosol emissions from forest fires may impact cloud droplet activation through an increase in particle number concentrations ("the number effect") and also through a decrease in the hygroscopicity κ of the entire aerosol population ("the hygroscopicity effect") when fully internal mixing is assumed in models. This study investigated these effects of fire particles on the properties of simulated deep convective clouds (DCCs), using cloud-resolving simulations with the Weather Research and Forecasting model coupled with Chemistry for a case study in a partly idealized setting. We found that the magnitude of the hygroscopicity effect was in some cases strong enough to entirely offset the number/size effect, in terms of its influence on modeled droplet and ice crystal concentrations. More specifically, in the case studied here, the droplet number concentration was reduced by about 37% or more due solely to the hygroscopicity effect. In the atmosphere, by contrast, fire particles likely have a much weaker impact on the hygroscopicity of the pre-existing background aerosol, as such a strong impact would occur only if the fire particles mixed immediately and uniformly with the background. We also show that the differences in the number of activated droplets eventually led to differences in the optical thickness of the clouds aloft, though this finding is limited to only a few hours of the initial development stage of the DCCs. These results suggest that accurately and rigorously representing aerosol mixing and κ in models is an important step toward accurately simulating aerosol-cloud interactions under the influence of fires.
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Affiliation(s)
- Azusa Takeishi
- Department of Geology and GeophysicsYale UniversityNew HavenCTUSA
- Currently at Laboratoire d'AérologieUniversity of Toulouse/CNRSToulouseFrance
| | | | - Laura Fierce
- Environmental and Climate Sciences DepartmentBrookhaven National LaboratoryUptonNYUSA
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21
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Liu T, Liu Q, Chen Y, Wang W, Zhang H, Li D, Sheng J. Effect of aerosols on the macro- and micro-physical properties of warm clouds in the Beijing-Tianjin-Hebei region. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 720:137618. [PMID: 32146402 DOI: 10.1016/j.scitotenv.2020.137618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 02/27/2020] [Accepted: 02/27/2020] [Indexed: 06/10/2023]
Abstract
The interaction between aerosols and clouds plays an important role in the climate system. There is still uncertainty about the influences of aerosols on the macro- and micro-physical properties of clouds in the Beijing-Tianjin-Hebei region. The relationships between aerosol optical depth (AOD) and the macro- and micro-physical properties of warm clouds in the Beijing-Tianjin-Hebei region were analyzed based on MODIS/Aqua data from 2007 to 2016. In addition, the ERA-Interim meteorological data was employed to investigate the relationship of AOD and cloud parameters under different meteorological conditions. The results showed that the variation of cloud droplet effective radius (CER) with AOD was in agreement with the Anti-Twomey effect, the main reason was that the increasing aerosol causes the water vapor competition effect among the cloud droplets, which makes the smaller cloud droplets evaporate. The multi-year average AOD was positively correlated with liquid water path (LWP). The relationship between AOD and cloud optical depth (COD) was quite different. When AOD was <0.4 or >0.8, COD increased with the increase of AOD, and when AOD was between 0.4 and 0.8, AOD and COD showed negative correlation. With the increment of AOD, cloud top pressure (CTP) also increased, which indicated that cloud top height decreased. When AOD was <0.3, cloud fraction (CF) was negatively correlated with AOD and conversely, positively correlated when AOD was >0.3. Furthermore, under most meteorological conditions, AOD was positively correlated with cloud macro- and micro-physical properties. Under the conditions of relative humidity ranged from 40% to 80%, there was a negative correlation between AOD and COD.
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Affiliation(s)
- Tongqiang Liu
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China
| | - Qiong Liu
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China.
| | - Yonghang Chen
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China.
| | - Wencai Wang
- Key Laboratory of Physical Oceanography, College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao 266100, China
| | - Hua Zhang
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China
| | - Dui Li
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China
| | - Jun Sheng
- College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China
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22
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Chen Z, Chen D, Zhao C, Kwan MP, Cai J, Zhuang Y, Zhao B, Wang X, Chen B, Yang J, Li R, He B, Gao B, Wang K, Xu B. Influence of meteorological conditions on PM 2.5 concentrations across China: A review of methodology and mechanism. ENVIRONMENT INTERNATIONAL 2020; 139:105558. [PMID: 32278201 DOI: 10.1016/j.envint.2020.105558] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 02/01/2020] [Accepted: 02/05/2020] [Indexed: 06/11/2023]
Abstract
Air pollution over China has attracted wide interest from public and academic community. PM2.5 is the primary air pollutant across China. Quantifying interactions between meteorological conditions and PM2.5 concentrations are essential to understand the variability of PM2.5 and seek methods to control PM2.5. Since 2013, the measurement of PM2.5 has been widely made at 1436 stations across the country and more than 300 papers focusing on PM2.5-meteorology interactions have been published. This article is a comprehensive review on the meteorological impact on PM2.5 concentrations. We start with an introduction of general meteorological conditions and PM2.5 concentrations across China, and then seasonal and spatial variations of meteorological influences on PM2.5 concentrations. Next, major methods used to quantify meteorological influences on PM2.5 concentrations are checked and compared. We find that causality analysis methods are more suitable for extracting the influence of individual meteorological factors whilst statistical models are good at quantifying the overall effect of multiple meteorological factors on PM2.5 concentrations. Chemical Transport Models (CTMs) have the potential to provide dynamic estimation of PM2.5 concentrations by considering anthropogenic emissions and the transport and evolution of pollutants. We then comprehensively examine the mechanisms how major meteorological factors may impact the PM2.5 concentrations, including the dispersion, growth, chemical production, photolysis, and deposition of PM2.5. The feedback effects of PM2.5 concentrations on meteorological factors are also carefully examined. Based on this review, suggestions on future research and major meteorological approaches for mitigating PM2.5 pollution are made finally.
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Affiliation(s)
- Ziyue Chen
- State Key Laboratory of Remote Sensing Science, College of Global and Earth System Sciences, Beijing Normal University, 19 Xinjiekou Street, Haidian, Beijing 100875, China; Joint Center for Global Change Studies, Beijing 100875, China
| | - Danlu Chen
- State Key Laboratory of Remote Sensing Science, College of Global and Earth System Sciences, Beijing Normal University, 19 Xinjiekou Street, Haidian, Beijing 100875, China
| | - Chuanfeng Zhao
- State Key Laboratory of Remote Sensing Science, College of Global and Earth System Sciences, Beijing Normal University, 19 Xinjiekou Street, Haidian, Beijing 100875, China; Joint Center for Global Change Studies, Beijing 100875, China
| | - Mei-Po Kwan
- Department of Geography and Resource Management, and Institute of Space and Earth Information Science, The Chinese University of Hong Kong, Hong Kong, China; Department of Human Geography and Spatial Planning, Utrecht University, 3584 CB Utrecht, the Netherlands
| | - Jun Cai
- Department of Earth System Science, Tsinghua University, Beijing 100084, China
| | - Yan Zhuang
- State Key Laboratory of Remote Sensing Science, College of Global and Earth System Sciences, Beijing Normal University, 19 Xinjiekou Street, Haidian, Beijing 100875, China
| | - Bo Zhao
- Department of Geography, University of Washington, Seattle, Washington 98195, USA
| | - Xiaoyan Wang
- State Key Laboratory of Remote Sensing Science, College of Global and Earth System Sciences, Beijing Normal University, 19 Xinjiekou Street, Haidian, Beijing 100875, China; Institute of Atmospheric Science, Fudan University, Shanghai 200433, China
| | - Bin Chen
- Department of Land, Air and Water Resources, University of California, Davis, CA 95616, USA
| | - Jing Yang
- State Key Laboratory of Earth Surface Processes and Resource Ecology (ESPRE), Faculty of Geographical Science, Beijing Normal University, 19 Xinjiekou Street, Haidian, Beijing 100875, China
| | - Ruiyuan Li
- State Key Laboratory of Remote Sensing Science, College of Global and Earth System Sciences, Beijing Normal University, 19 Xinjiekou Street, Haidian, Beijing 100875, China
| | - Bin He
- State Key Laboratory of Remote Sensing Science, College of Global and Earth System Sciences, Beijing Normal University, 19 Xinjiekou Street, Haidian, Beijing 100875, China; Joint Center for Global Change Studies, Beijing 100875, China
| | - Bingbo Gao
- China College of Land Science and Technology, China Agriculture University, Tsinghua East Road, Haidian District, Beijing 100083, China
| | - Kaicun Wang
- State Key Laboratory of Remote Sensing Science, College of Global and Earth System Sciences, Beijing Normal University, 19 Xinjiekou Street, Haidian, Beijing 100875, China; Joint Center for Global Change Studies, Beijing 100875, China.
| | - Bing Xu
- Department of Earth System Science, Tsinghua University, Beijing 100084, China.
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23
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Allan RP, Barlow M, Byrne MP, Cherchi A, Douville H, Fowler HJ, Gan TY, Pendergrass AG, Rosenfeld D, Swann ALS, Wilcox LJ, Zolina O. Advances in understanding large-scale responses of the water cycle to climate change. Ann N Y Acad Sci 2020; 1472:49-75. [PMID: 32246848 DOI: 10.1111/nyas.14337] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/03/2020] [Accepted: 03/06/2020] [Indexed: 11/30/2022]
Abstract
Globally, thermodynamics explains an increase in atmospheric water vapor with warming of around 7%/°C near to the surface. In contrast, global precipitation and evaporation are constrained by the Earth's energy balance to increase at ∼2-3%/°C. However, this rate of increase is suppressed by rapid atmospheric adjustments in response to greenhouse gases and absorbing aerosols that directly alter the atmospheric energy budget. Rapid adjustments to forcings, cooling effects from scattering aerosol, and observational uncertainty can explain why observed global precipitation responses are currently difficult to detect but are expected to emerge and accelerate as warming increases and aerosol forcing diminishes. Precipitation increases with warming are expected to be smaller over land than ocean due to limitations on moisture convergence, exacerbated by feedbacks and affected by rapid adjustments. Thermodynamic increases in atmospheric moisture fluxes amplify wet and dry events, driving an intensification of precipitation extremes. The rate of intensification can deviate from a simple thermodynamic response due to in-storm and larger-scale feedback processes, while changes in large-scale dynamics and catchment characteristics further modulate the frequency of flooding in response to precipitation increases. Changes in atmospheric circulation in response to radiative forcing and evolving surface temperature patterns are capable of dominating water cycle changes in some regions. Moreover, the direct impact of human activities on the water cycle through water abstraction, irrigation, and land use change is already a significant component of regional water cycle change and is expected to further increase in importance as water demand grows with global population.
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Affiliation(s)
- Richard P Allan
- Department of Meteorology and National Centre for Earth Observation, University of Reading, Reading, United Kingdom
| | - Mathew Barlow
- Department of Environmental Earth and Atmospheric Sciences, University of Massachusetts Lowell, Lowell, Massachusetts
| | - Michael P Byrne
- School of Earth and Environmental Science, University of St Andrews, St Andrews, United Kingdom.,Department of Physics, University of Oxford, Oxford, United Kingdom
| | - Annalisa Cherchi
- Istituto Nazionale di Geofisica e Vulcanologia Sezione di Bologna, INGV, Bologna, Italy
| | - Hervé Douville
- Centre National de Recherches Météorologiques, Météo-France/CNRS, Toulouse, France
| | - Hayley J Fowler
- University of Newcastle, Newcastle upon Tyne, United Kingdom
| | - Thian Y Gan
- University of Alberta, Edmonton, Alberta, Canada
| | | | - Daniel Rosenfeld
- Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.,School of Atmospheric Sciences, Nanjing University, Nanjing, China
| | | | - Laura J Wilcox
- National Centre for Atmospheric Science, Department of Meteorology, University of Reading, Reading, United Kingdom
| | - Olga Zolina
- L'Institut des Géosciences de l'Environnement/Centre National de la Recherche Scientifique, L'Université Grenoble Alpes, Grenoble, France.,P. P. Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia
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24
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Retrieval and Validation of Cloud Top Temperature from the Geostationary Satellite INSAT-3D. REMOTE SENSING 2019. [DOI: 10.3390/rs11232811] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Investigation of cloud top temperature (CTT) and its diurnal variation is highly reliant on high spatial and temporal resolution satellite data, which is lacking over the Indian region. An algorithm has been developed for detection of clouds and retrieval of CTT from the geostationary satellite INSAT-3D. These retrievals are validated (inter-compared) with collocated in-situ (satellite) measurements with specific intent to generate climate-quality data. The cloud detection algorithm employs nine different tests, in accordance with solar illumination, satellite angle and surface type conditions to generate pixel-resolution cloud mask. Validation of cloud mask with cloud-aerosol lidar with orthogonal polarization (CALIOP) shows that probability of detection (POD) of cloudy (clear) sky is 81% (85%), with 83% hit rate. The algorithm is also implemented on similar channels of moderate resolution imaging spectroradiometer (MODIS), which provides 88% (83%) POD of cloudy (clear) sky, with 86% hit rate. CTT retrieval is done at the pixel level, for all cloud pixels, by employing appropriate methods for various types of clouds. Comparison of CTT with radiosonde and cloud-aerosol lidar and infrared pathfinder satellite observations (CALIPSO) shows mean absolute error less than 3%. The study also examines sensitivity of retrieved CTT to the cloud classification scheme and retrieval criteria. Validation results and their close agreements with those of similar satellites demonstrate the reliability of the retrieved product for climate studies.
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25
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Morgan WT, Darbyshire E, Spracklen DV, Artaxo P, Coe H. Non-deforestation drivers of fires are increasingly important sources of aerosol and carbon dioxide emissions across Amazonia. Sci Rep 2019; 9:16975. [PMID: 31740689 PMCID: PMC6861235 DOI: 10.1038/s41598-019-53112-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 10/23/2019] [Indexed: 11/26/2022] Open
Abstract
Deforestation rates have declined substantially across the Brazilian Legal Amazon (BLA) over the period from 2000–2017. However, reductions in fire, aerosol and carbon dioxide have been far less significant than deforestation, even when accounting for inter-annual variability in precipitation. Our observations and analysis support a decoupling between fire and deforestation that has exacerbated forest degradation in the BLA. Basing aerosol and carbon dioxide emissions on deforestation rates, without accounting for forest degradation will bias these important climate and ecosystem-health parameters low, both now and in the future. Recent increases in deforestation rate since 2014 will enhance such degradation, particularly during drought-conditions, increasing emissions of aerosol and greenhouse gases. Given Brazil’s committed Nationally Determined Contribution under the Paris Agreement, failure to account for forest degradation fires will paint a false picture of prior progress and potentially have profound implications for both regional and global climate.
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Affiliation(s)
- William T Morgan
- School of Earth & Environmental Sciences, University of Manchester, Manchester, UK
| | - Eoghan Darbyshire
- School of Earth & Environmental Sciences, University of Manchester, Manchester, UK
| | | | - Paulo Artaxo
- Physics Institute, University of Sao Paulo, Sao Paulo, Brazil
| | - Hugh Coe
- School of Earth & Environmental Sciences, University of Manchester, Manchester, UK.
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26
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Buysse CE, Kaulfus A, Nair U, Jaffe DA. Relationships between Particulate Matter, Ozone, and Nitrogen Oxides during Urban Smoke Events in the Western US. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:12519-12528. [PMID: 31597429 DOI: 10.1021/acs.est.9b05241] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Urban ozone (O3) pollution is influenced by the transport of wildfire smoke but observed impacts are highly variable. We investigate O3 impacts from smoke in 18 western US cities during July-September, 2013-2017, with ground-based monitoring data from air quality system sites, using satellite-based hazard mapping system (HMS) fire and smoke product to identify overhead smoke. We present four key findings. First, O3 and PM2.5 (particulate matter <2.5 μm in diameter) are elevated at nearly all sites on days influenced by smoke, with the greatest mean enhancement occurring during multiday smoke events; nitrogen oxides (NOx) are not consistently elevated across all sites. Second, PM2.5 and O3 exhibit a nonlinear relationship such that O3 increases with PM2.5 at low to moderate 24 h PM2.5, peaks around 30-50 μg m-3, and declines at higher PM2.5. Third, the rate of increase of morning O3 is higher and NO/NO2 ratios are lower on smoke-influenced days, which could result from additional atmospheric oxidants in smoke. Fourth, while the HMS product is a useful tool for identifying smoke, O3 and PM2.5 are elevated on days before and after HMS-identified smoke events implying that a significant fraction of smoke events is not detected.
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Affiliation(s)
- Claire E Buysse
- Department of Atmospheric Sciences , University of Washington , Seattle , Washington 98195 , United States
| | - Aaron Kaulfus
- Department of Atmospheric Science , University of Alabama in Huntsville , Huntsville , Alabama 35899 , United States
| | - Udaysankar Nair
- Department of Atmospheric Science , University of Alabama in Huntsville , Huntsville , Alabama 35899 , United States
| | - Daniel A Jaffe
- Department of Atmospheric Sciences , University of Washington , Seattle , Washington 98195 , United States
- School of Science, Technology, Engineering, and Mathematics , University of Washington-Bothell , Bothell , Washington 98011 , United States
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27
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Ferrero L, Ritter C, Cappelletti D, Moroni B, Močnik G, Mazzola M, Lupi A, Becagli S, Traversi R, Cataldi M, Neuber R, Vitale V, Bolzacchini E. Aerosol optical properties in the Arctic: The role of aerosol chemistry and dust composition in a closure experiment between Lidar and tethered balloon vertical profiles. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 686:452-467. [PMID: 31185395 DOI: 10.1016/j.scitotenv.2019.05.399] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 05/21/2019] [Accepted: 05/26/2019] [Indexed: 06/09/2023]
Abstract
A closure experiment was conducted over Svalbard by comparing Lidar measurements and optical aerosol properties calculated from aerosol vertical profiles measured using a tethered balloon. Arctic Haze was present together with Icelandic dust. Chemical analysis of filter samples, aerosol size distribution and a full set of meteorological parameters were determined at ground. Moreover, scanning electron microscopy coupled with energy-dispersive X-ray (SEM-EDS) data were at disposal showing the presence of several mineralogical phases (i.e., sheet silicates, gypsum, quartz, rutile, hematite). The closure experiment was set up by calculating the backscattering coefficients from tethered balloon data and comparing them with the corresponding lidar profiles. This was preformed in three subsequent steps aimed at determining the importance of a complete aerosol speciation: (i) a simple, columnar refractive index was obtained by the closest Aerosol Robotic Network (AERONET) station, (ii) the role of water-soluble components, elemental carbon and organic matter (EC/OM) was addressed, (iii) the dust composition was included. When considering the AERONET data, or only the ionic water-soluble components and the EC/OM fraction, results showed an underestimation of the backscattering lidar signal up to 76, 53 and 45% (355, 532 and 1064 nm). Instead, when the dust contribution was included, the underestimation disappeared and the vertically-averaged, backscattering coefficients (1.45 ± 0.30, 0.69 ± 0.15 and 0.34 ± 0.08 Mm-1 sr-1, at 355, 532 and 1064 nm) were found in keeping with the lidar ones (1.60 ± 0.22, 0.75 ± 0.16 and 0.31 ± 0.08 Mm-1 sr-1). Final results were characterized by low RMSE (0.36, 0.08 and 0.04 Mm-1 sr-1) and a high linear correlation (R2 of 0.992, 0.992 and 0.994) with slopes close to one (1.368, 0.931 and 0.977, respectively). This work highlighted the importance of all the aerosol components and of the synergy between single particle and bulk chemical analysis for the optical property characterization in the Arctic.
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Affiliation(s)
- L Ferrero
- GEMMA and POLARIS Research Centers, Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy.
| | - C Ritter
- Alfred-Wegener Institut für Polar- und Meeresforschung (AWI), Forschungsstelle Potsdam, Telegraphenberg 43A, 14473 Potsdam, Germany
| | - D Cappelletti
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy; National Research Council, Institute of Atmospheric Sciences and Climate, (CNR-ISAC), Via P. Gobetti 101, 40129 Bologna, Italy
| | - B Moroni
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - G Močnik
- Department of Condensed Matter Physics, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - M Mazzola
- National Research Council, Institute of Atmospheric Sciences and Climate, (CNR-ISAC), Via P. Gobetti 101, 40129 Bologna, Italy
| | - A Lupi
- National Research Council, Institute of Atmospheric Sciences and Climate, (CNR-ISAC), Via P. Gobetti 101, 40129 Bologna, Italy
| | - S Becagli
- National Research Council, Institute of Atmospheric Sciences and Climate, (CNR-ISAC), Via P. Gobetti 101, 40129 Bologna, Italy; Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy
| | - R Traversi
- National Research Council, Institute of Atmospheric Sciences and Climate, (CNR-ISAC), Via P. Gobetti 101, 40129 Bologna, Italy; Department of Chemistry, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy
| | - M Cataldi
- GEMMA and POLARIS Research Centers, Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy
| | - R Neuber
- Alfred-Wegener Institut für Polar- und Meeresforschung (AWI), Forschungsstelle Potsdam, Telegraphenberg 43A, 14473 Potsdam, Germany
| | - V Vitale
- National Research Council, Institute of Atmospheric Sciences and Climate, (CNR-ISAC), Via P. Gobetti 101, 40129 Bologna, Italy
| | - E Bolzacchini
- GEMMA and POLARIS Research Centers, Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy
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28
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Abstract
Haze pollution has frequently occurred in winter over Eastern China in recent years. Over Eastern China, Moderate Resolution Imaging Spectroradiometer (MODIS) cloud detection data were compared with the Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP) for three years (2013–2016) for three kinds of underlying surface types (dark, bright, and water). We found that MODIS and CALIOP agree most of the time (82% on average), but discrepancies occurred at low CALIOP cloud optical thickness (COT < 0.4) and low MODIS cloud top height (CTH < 1.5 km). In spring and summer, the CALIOP cloud fraction was higher by more than 0.1 than MODIS due to MODIS’s incapability of observing clouds with a lower COT. The discrepancy increased significantly with a decrease in MODIS CTH and an increase in aerosol optical depth (AOD, about 2–4 times), and MODIS observed more clouds that were undetected by CALIOP over PM2.5 > 75 μg m−3 regions in autumn and particularly in winter, suggesting that polluted weather over Eastern China may contaminate MODIS cloud detections because MODIS will misclassify a heavy aerosol layer as cloudy under intense haze conditions. Besides aerosols, the high solar zenith angle (SZA) in winter also affects MODIS cloud detection, and the ratio of MODIS cloud pixel numbers to CALIOP cloud-free pixel numbers at a high SZA increased a great deal (about 4–21 times) relative to that at low SZA for the three surfaces. As a result of the effects of aerosol and SZA, MODIS cloud fraction was 0.08 higher than CALIOP, and MODIS CTH was more than 2 km lower than CALIOP CTH in winter. As for the cloud phases and types, the results showed that most of the discrepancies could be attributed to water clouds and low clouds (cumulus and stratocumulus), which is consistent with most of the discrepancies at low MODIS CTH.
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29
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Liu H, Guo J, Koren I, Altaratz O, Dagan G, Wang Y, Jiang JH, Zhai P, Yung YL. Non-Monotonic Aerosol Effect on Precipitation in Convective Clouds over Tropical Oceans. Sci Rep 2019; 9:7809. [PMID: 31127137 PMCID: PMC6534586 DOI: 10.1038/s41598-019-44284-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 05/14/2019] [Indexed: 11/22/2022] Open
Abstract
Aerosol effects on convective clouds and associated precipitation constitute an important open-ended question in climate research. Previous studies have linked an increase in aerosol concentration to a delay in the onset of rain, invigorated clouds and stronger rain rates. Here, using observational data, we show that the aerosol effect on convective clouds shifts from invigoration to suppression with increasing aerosol optical depth. We explain this shift in trend (using a cloud model) as the result of a competition between two types of microphysical processes: cloud-core-based invigorating processes vs. peripheral suppressive processes. We show that the aerosol optical depth value that marks the shift between invigoration and suppression depends on the environmental thermodynamic conditions. These findings can aid in better parameterizing aerosol effects in climate models for the prediction of climate trends.
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Affiliation(s)
- Huan Liu
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, 100081, China.,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.,Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Jianping Guo
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, 100081, China.
| | - Ilan Koren
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel.
| | - Orit Altaratz
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Guy Dagan
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Yuan Wang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Jonathan H Jiang
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA
| | - Panmao Zhai
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, 100081, China
| | - Yuk L Yung
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
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30
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Chemical Composition of Aerosol over the Arctic Ocean from Summer ARctic EXpedition (AREX) 2011–2012 Cruises: Ions, Amines, Elemental Carbon, Organic Matter, Polycyclic Aromatic Hydrocarbons, n-Alkanes, Metals, and Rare Earth Elements. ATMOSPHERE 2019. [DOI: 10.3390/atmos10020054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
During the summers of 2011 and 2012, two scientific cruises were carried out over the Arctic Ocean aiming at the determination of the aerosol chemical composition in this pristine environment. First, mass spectrometry was applied to study the concentration and gas/particle partitioning of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes. Experimental and modelled data of phase partitioning were compared: results demonstrated an equilibrium between gas and particle phase for PAHs, while n-alkanes showed a particle-oriented partitioning, due to the local marine origin of them, confirmed by the extremely low value of their carbon preference index. Moreover, the inorganic and organic ions (carboxylic acids and amines) concentrations, together with those of elemental carbon (EC) and organic matter (OM), were analyzed: 63% of aerosol was composed of ionic compounds (>90% from sea-salt) and the OM content was very high (30.5%; close to 29.0% of Cl−) in agreement with n-alkanes’ marine signature. Furthermore, the amines’ (dimethylamine, trimethylamine, diethylamine) concentrations were 3.98 ± 1.21, 1.70 ± 0.82, and 1.06 ± 0.56 p.p.t.v., respectively, fully in keeping with concentration values used in the CLOUD (Cosmics Leaving OUtdoor Droplet)-chamber experiments to simulate the ambient nucleation rate in a H2SO4-DMA-H2O system, showing the amines’ importance in polar regions to promote new particle formation. Finally, high resolution mass spectrometry was applied to determine trace elements, including Rare Earth Elements (REEs), highlighting the dominant natural versus anthropic inputs for trace metals (e.g., Fe, Mn, Ti vs. As, Cd, Ni) and possible signatures of such anthropic activity.
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31
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Rosenfeld D, Zhu Y, Wang M, Zheng Y, Goren T, Yu S. Aerosol-driven droplet concentrations dominate coverage and water of oceanic low-level clouds. Science 2019; 363:science.aav0566. [PMID: 30655446 DOI: 10.1126/science.aav0566] [Citation(s) in RCA: 136] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 01/09/2019] [Indexed: 11/02/2022]
Abstract
A lack of reliable estimates of cloud condensation nuclei (CCN) aerosols over oceans has severely limited our ability to quantify their effects on cloud properties and extent of cooling by reflecting solar radiation-a key uncertainty in anthropogenic climate forcing. We introduce a methodology for ascribing cloud properties to CCN and isolating the aerosol effects from meteorological effects. Its application showed that for a given meteorology, CCN explains three-fourths of the variability in the radiative cooling effect of clouds, mainly through affecting shallow cloud cover and water path. This reveals a much greater sensitivity of cloud radiative forcing to CCN than previously reported, which means too much cooling if incorporated into present climate models. This suggests the existence of compensating aerosol warming effects yet to be discovered, possibly through deep clouds.
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Affiliation(s)
- Daniel Rosenfeld
- Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel. .,School of Atmospheric Sciences, Nanjing University, China
| | - Yannian Zhu
- Meteorological Institute of Shaanxi Province, Xi'an, China
| | - Minghuai Wang
- School of Atmospheric Sciences, Nanjing University, China. .,Joint International Research Laboratory of Atmospheric and Earth System Sciences and Institute for Climate and Global Change Research, Nanjing University, China
| | - Youtong Zheng
- Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA
| | - Tom Goren
- University of Leipzig, Leipzig, Germany
| | - Shaocai Yu
- Research Center for Air Pollution and Health; Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Education, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, P.R. China. .,Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91123, USA.,Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, Fujian 361021, P.R. China
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Jiang JH, Su H, Huang L, Wang Y, Massie S, Zhao B, Omar A, Wang Z. Contrasting effects on deep convective clouds by different types of aerosols. Nat Commun 2018; 9:3874. [PMID: 30250192 PMCID: PMC6155150 DOI: 10.1038/s41467-018-06280-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 07/27/2018] [Indexed: 11/09/2022] Open
Abstract
Convective clouds produce a significant proportion of the global precipitation and play an important role in the energy and water cycles. We quantify changes of the convective cloud ice mass-weighted altitude centroid (ZIWC) as a function of aerosol optical thickness (AOT). Analyses are conducted in smoke, dust and polluted continental aerosol environments over South America, Central Africa and Southeast Asia, using the latest measurements from the CloudSat and CALIPSO satellites. We find aerosols can inhibit or invigorate convection, depending on aerosol type and concentration. On average, smoke tends to suppress convection and results in lower ZIWC than clean clouds. Polluted continental aerosol tends to invigorate convection and promote higher ZIWC. The dust aerosol effects are regionally dependent and their signs differ from place to place. Moreover, we find that the aerosol inhibition or invigoration effects do not vary monotonically with AOT and the variations depend strongly on aerosol type. Our observational findings indicate that aerosol type is one of the key factors in determining the aerosol effects on convective clouds.
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Affiliation(s)
- Jonathan H Jiang
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, 91109, CA, USA.
| | - Hui Su
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, 91109, CA, USA
| | - Lei Huang
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, 91109, CA, USA
- Joint Institute for Regional Earth System Science and Engineering, University of California, Los Angeles, 90095, CA, USA
| | - Yuan Wang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, 91106, CA, USA
| | - Steven Massie
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, 80309, CO, USA
| | - Bin Zhao
- Joint Institute for Regional Earth System Science and Engineering, University of California, Los Angeles, 90095, CA, USA
| | - Ali Omar
- NASA Langley Research Center, Hampton, 23681, VA, USA
| | - Zhien Wang
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, 80309, CO, USA
- Department of Atmospheric Science, University of Wyoming, Laramie, 82071, WY, USA
- Department of Atmospheric and Oceanic Sciences, University of Colorado, Boulder, 80309, CO, USA
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Levy RC, Mattoo S, Sawyer V, Shi Y, Colarco PR, Lyapustin AI, Wang Y, Remer LA. Exploring systematic offsets between aerosol products from the two MODIS sensors. ATMOSPHERIC MEASUREMENT TECHNIQUES 2018; 11:4073-4092. [PMID: 32676129 PMCID: PMC7365259 DOI: 10.5194/amt-11-4073-2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Long-term measurements of global aerosol loading and optical properties are essential for assessing climate-related questions. Using observations of spectral reflectance and radiance, the dark-target (DT) aerosol retrieval algorithm is applied to Moderate-resolution Imaging Spectroradiometer sensors on both Terra (MODIS-T) and Aqua (MODIS-A) satellites, deriving products (known as MOD04 and MYD04, respectively) of global aerosol optical depth (AOD at 0.55 μm) over both land and ocean, and Angstrom Exponent (AE derived from 0.55 and 0.86 μm) over ocean. Here, we analyse the overlapping time series (since mid-2002) of the Collection 6 (C6) aerosol products. Global monthly mean AOD from MOD04 (Terra with morning overpass) is consistently higher than MYD04 (Aqua with afternoon overpass) by ~13% (~0.02 over land and ~0.015 over ocean), and this offset (MOD04 - MYD04), has seasonal as well as long-term variability. Focusing on 2008, and deriving yearly gridded mean AOD and AE, we find that over ocean, the MOD04 (morning) AOD is higher and the AE is lower. Over land, there is more variability, but only biomass-burning regions tend to have AOD lower for MOD04. Using simulated aerosol fields from the Goddard Earth Observing System (GEOS-5) Earth system model, and sampling separately (in time and space) along each MODIS-observed swath during 2008, the magnitudes of morning versus afternoon offsets of AOD and AE are smaller than those in the C6 products. Since the differences are not easily attributed to either aerosol diurnal cycles or sampling issues, we test additional corrections to the input reflectance data. The first, known as C6+, corrects for long-term changes to each sensors' polarization sensitivity, response-versus-scan angle, and to cross-calibration from MODIS-T to MODIS-A. A second convolves the de-trending and cross-calibration into scaling factors. Each method was applied upstream of the aerosol retrieval, using 2008 data. While both methods reduced the overall AOD offset over land from 0.02 to 0.01, neither significantly reduced the AOD offset over ocean. The overall negative AE offset was reduced. A Collection (C6.1) of all MODIS-atmosphere products was released, but we expect that the C6.1 aerosol products will maintain similar overall AOD and AE offsets. We conclude that: a) users should not interpret global differences between Terra and Aqua aerosol products as representing a true diurnal signal in the aerosol. b) Because the MODIS-A product appears to have overall smaller bias compared to ground-truth, it may be more suitable for some applications, however c) since the AOD offset is only ~0.02 and within noise level for single retrievals, both MODIS products may be adequate for most applications.
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Affiliation(s)
- Robert C. Levy
- NASA-Goddard Space Flight Center (GSFC), Greenbelt, Maryland, USA
| | - Shana Mattoo
- NASA-Goddard Space Flight Center (GSFC), Greenbelt, Maryland, USA
- Science Systems and Applications (SSAI), Lanham, Maryland, USA
| | - Virginia Sawyer
- NASA-Goddard Space Flight Center (GSFC), Greenbelt, Maryland, USA
- Science Systems and Applications (SSAI), Lanham, Maryland, USA
| | - Yingxi Shi
- NASA-Goddard Space Flight Center (GSFC), Greenbelt, Maryland, USA
- University Space Research Association (USRA), Columbia, Maryland, USA
| | - Peter R. Colarco
- NASA-Goddard Space Flight Center (GSFC), Greenbelt, Maryland, USA
| | | | - Yujie Wang
- NASA-Goddard Space Flight Center (GSFC), Greenbelt, Maryland, USA
- University of Maryland-Baltimore County (UMBC), Baltimore, Maryland, USA
| | - Lorraine A. Remer
- University of Maryland-Baltimore County (UMBC), Baltimore, Maryland, USA
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Zhao B, Gu Y, Liou KN, Wang Y, Liu X, Huang L, Jiang JH, Su H. Type-Dependent Responses of Ice Cloud Properties to Aerosols From Satellite Retrievals. GEOPHYSICAL RESEARCH LETTERS 2018; 45:3297-3306. [PMID: 31631917 PMCID: PMC6800730 DOI: 10.1002/2018gl077261] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 03/24/2018] [Indexed: 05/25/2023]
Abstract
Aerosol-cloud interactions represent one of the largest uncertainties in external forcings on our climate system. Compared with liquid clouds, the observational evidence for the aerosol impact on ice clouds is much more limited and shows conflicting results, partly because the distinct features of different ice cloud and aerosol types were seldom considered. Using 9-year satellite retrievals, we find that, for convection-generated (anvil) ice clouds, cloud optical thickness, cloud thickness, and cloud fraction increase with small-to-moderate aerosol loadings (<0.3 aerosol optical depth) and decrease with further aerosol increase. For in situ formed ice clouds, however, these cloud properties increase monotonically and more sharply with aerosol loadings. An increase in loading of smoke aerosols generally reduces cloud optical thickness of convection-generated ice clouds, while the reverse is true for dust and anthropogenic pollution aerosols. These relationships between different cloud/aerosol types provide valuable constraints on the modeling assessment of aerosol-ice cloud radiative forcing.
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Affiliation(s)
- Bin Zhao
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA, USA
- Jet propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Yu Gu
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA, USA
| | - Kuo-Nan Liou
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA, USA
| | - Yuan Wang
- Jet propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Xiaohong Liu
- Department of Atmospheric Science, University of Wyoming, Laramie, WY, USA
| | - Lei Huang
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA, USA
- Jet propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Jonathan H Jiang
- Jet propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Hui Su
- Jet propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
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Ferrero L, Močnik G, Cogliati S, Gregorič A, Colombo R, Bolzacchini E. Heating Rate of Light Absorbing Aerosols: Time-Resolved Measurements, the Role of Clouds, and Source Identification. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:3546-3555. [PMID: 29474062 DOI: 10.1021/acs.est.7b04320] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Light absorbing aerosols (LAA) absorb sunlight and heat the atmosphere. This work presents a novel methodology to experimentally quantify the heating rate (HR) induced by LAA into an atmospheric layer. Multiwavelength aerosol absorption measurements were coupled with spectral measurements of the direct, diffuse and surface reflected radiation to obtain highly time-resolved measurements of HR apportioned in the context of LAA species (black carbon, BC; brown carbon, BrC; dust), sources (fossil fuel, FF; biomass burning, BB), and as a function of cloudiness. One year of continuous and time-resolved measurements (5 min) of HR were performed in the Po Valley. We experimentally determined (1) the seasonal behavior of HR (winter 1.83 ± 0.02 K day-1; summer 1.04 ± 0.01 K day-1); (2) the daily cycle of HR (asymmetric, with higher values in the morning than in the afternoon); (3) the HR in different sky conditions (from 1.75 ± 0.03 K day-1 in clear sky to 0.43 ± 0.01 K day-1 in complete overcast); (4) the apportionment to different sources: HRFF (0.74 ± 0.01 K day-1) and HRBB (0.46 ± 0.01 K day-1); and (4) the HR of BrC (HRBrC: 0.15 ± 0.01 K day-1, 12.5 ± 0.6% of the total) and that of BC (HRBC: 1.05 ± 0.02 K day-1; 87.5 ± 0.6% of the total).
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Affiliation(s)
- Luca Ferrero
- POLARIS Research Centre, Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
- GEMMA Centre, Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
| | - Griša Močnik
- Aerosol d.o.o. , Kamniška 41 , SI-1000 Ljubljana , Slovenia
- Department of Condensed Matter Physics , Jozef Stefan Institute , Jamova 39 , SI-1000 Ljubljana , Slovenia
| | - Sergio Cogliati
- GEMMA Centre, Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
- Remote Sensing of Environmental Dynamics Lab., Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
| | - Asta Gregorič
- Aerosol d.o.o. , Kamniška 41 , SI-1000 Ljubljana , Slovenia
- Center for Atmospheric Research , University of Nova Gorica , SI-5000 Nova Gorica , Slovenia
| | - Roberto Colombo
- GEMMA Centre, Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
- Remote Sensing of Environmental Dynamics Lab., Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
| | - Ezio Bolzacchini
- POLARIS Research Centre, Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
- GEMMA Centre, Department of Earth and Environmental Sciences , University of Milano-Bicocca , 20126 , Milano , Italy
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Fan J, Rosenfeld D, Zhang Y, Giangrande SE, Li Z, Machado LAT, Martin ST, Yang Y, Wang J, Artaxo P, Barbosa HMJ, Braga RC, Comstock JM, Feng Z, Gao W, Gomes HB, Mei F, Pöhlker C, Pöhlker ML, Pöschl U, de Souza RAF. Substantial convection and precipitation enhancements by ultrafine aerosol particles. Science 2018; 359:411-418. [DOI: 10.1126/science.aan8461] [Citation(s) in RCA: 208] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 12/22/2017] [Indexed: 11/02/2022]
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Zhao X, Liu Y, Yu F, Heidinger AK. Using Long-Term Satellite Observations to Identify Sensitive Regimes and Active Regions of Aerosol Indirect Effects for Liquid Clouds Over Global Oceans. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2018; 123:457-472. [PMID: 29527427 PMCID: PMC5832308 DOI: 10.1002/2017jd027187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 09/19/2017] [Accepted: 11/13/2017] [Indexed: 03/14/2024]
Abstract
Long-term (1981-2011) satellite climate data records of clouds and aerosols are used to investigate the aerosol-cloud interaction of marine water cloud from a climatology perspective. Our focus is on identifying the regimes and regions where the aerosol indirect effects (AIEs) are evident in long-term averages over the global oceans through analyzing the correlation features between aerosol loading and the key cloud variables including cloud droplet effective radius (CDER), cloud optical depth (COD), cloud water path (CWP), cloud top height (CTH), and cloud top temperature (CTT). An aerosol optical thickness (AOT) range of 0.13 < AOT < 0.3 is identified as the sensitive regime of the conventional first AIE where CDER is more susceptible to AOT than the other cloud variables. The first AIE that manifests as the change of long-term averaged CDER appears only in limited oceanic regions. The signature of aerosol invigoration of water clouds as revealed by the increase of cloud cover fraction (CCF) and CTH with increasing AOT at the middle/high latitudes of both hemispheres is identified for a pristine atmosphere (AOT < 0.08). Aerosol invigoration signature is also revealed by the concurrent increase of CDER, COD, and CWP with increasing AOT for a polluted marine atmosphere (AOT > 0.3) in the tropical convergence zones. The regions where the second AIE is likely to manifest in the CCF change are limited to several oceanic areas with high CCF of the warm water clouds near the western coasts of continents. The second AIE signature as represented by the reduction of the precipitation efficiency with increasing AOT is more likely to be observed in the AOT regime of 0.08 < AOT < 0.4. The corresponding AIE active regions manifested themselves as the decline of the precipitation efficiency are mainly limited to the oceanic areas downwind of continental aerosols. The sensitive regime of the conventional AIE identified in this observational study is likely associated with the transitional regime from the aerosol-limited regime to the updraft-limited regime identified for aerosol-cloud interaction in cloud model simulations.
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Affiliation(s)
- Xuepeng Zhao
- National Centers for Environmental InformationNOAA/NESDISSilver SpringMDUSA
| | - Yangang Liu
- Environmental and Climate Sciences DepartmentBrookhaven National LaboratoryUptonNYUSA
| | - Fangquan Yu
- Atmospheric Sciences Research CenterState University of New York at AlbanyAlbanyNYUSA
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Fu C, Dan L. The variation of cloud amount and light rainy days under heavy pollution over South China during 1960-2009. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:2369-2376. [PMID: 29124639 PMCID: PMC5773615 DOI: 10.1007/s11356-017-0510-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 10/18/2017] [Indexed: 06/07/2023]
Abstract
The ground observation data was used to analyze the variation of cloud amount and light precipitation over South China during 1960-2009. The total cloud cover (TCC) decreases in this period, whereas the low cloud cover (LCC) shows the obvious opposite change with increasing trends. LCP defined as low cloud cover/total cloud cover has increased, and small rainy days (< 10 mm day-1) decreased significantly (passing 0.001 significance level) during the past 50 years, which is attributed to the enhanced levels of air pollution in the form of anthropogenic aerosols. The horizontal visibility and sunshine duration are used to depict the anthropogenic aerosol loading. When horizontal visibility declines to 20 km or sunshine duration decreases to 5 h per day, LCC increases 52% or more and LCP increases significantly. The correlation coefficients between LCC and horizontal visibility or sunshine duration are - 0.533 and - 0.927, and the values between LCP and horizontal visibility or sunshine duration are - 0.849 and - 0.641, which pass 0.001 significance level. The results indicated that aerosols likely impacted the long-term trend of cloud amount and light precipitation over South China.
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Affiliation(s)
- Chuanbo Fu
- Hainan Meteorological Observatory, Haikou, 570203, China.
- Key Laboratory of Regional Climate-Environment Research for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China.
| | - Li Dan
- Key Laboratory of Regional Climate-Environment Research for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China
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Svensmark H, Enghoff MB, Shaviv NJ, Svensmark J. Increased ionization supports growth of aerosols into cloud condensation nuclei. Nat Commun 2017; 8:2199. [PMID: 29259163 PMCID: PMC5736571 DOI: 10.1038/s41467-017-02082-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 11/03/2017] [Indexed: 11/09/2022] Open
Abstract
Ions produced by cosmic rays have been thought to influence aerosols and clouds. In this study, the effect of ionization on the growth of aerosols into cloud condensation nuclei is investigated theoretically and experimentally. We show that the mass-flux of small ions can constitute an important addition to the growth caused by condensation of neutral molecules. Under atmospheric conditions the growth from ions can constitute several percent of the neutral growth. We performed experimental studies which quantify the effect of ions on the growth of aerosols between nucleation and sizes >20 nm and find good agreement with theory. Ion-induced condensation should be of importance not just in Earth’s present day atmosphere for the growth of aerosols into cloud condensation nuclei under pristine marine conditions, but also under elevated atmospheric ionization caused by increased supernova activity. Ions produced by cosmic rays have been thought to influence aerosol and cloud processes by an unknown mechanism. Here the authors show that the mass flux of ions to aerosols enhances their growth significantly, with implications for the formation of cloud condensation nuclei.
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Affiliation(s)
- H Svensmark
- National Space Institute, Technical University of Denmark, Elektrovej, Building 328, 2800, Lyngby, Denmark.
| | - M B Enghoff
- National Space Institute, Technical University of Denmark, Elektrovej, Building 328, 2800, Lyngby, Denmark
| | - N J Shaviv
- Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - J Svensmark
- National Space Institute, Technical University of Denmark, Elektrovej, Building 328, 2800, Lyngby, Denmark.,Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100, Copenhagen, Denmark
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40
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Aerosols cause intraseasonal short-term suppression of Indian monsoon rainfall. Sci Rep 2017; 7:17347. [PMID: 29229964 PMCID: PMC5725429 DOI: 10.1038/s41598-017-17599-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 11/24/2017] [Indexed: 11/23/2022] Open
Abstract
Aerosol abundance over South Asia during the summer monsoon season, includes dust and sea-salt, as well as, anthropogenic pollution particles. Using observations during 2000–2009, here we uncover repeated short-term rainfall suppression caused by coincident aerosols, acting through atmospheric stabilization, reduction in convection and increased moisture divergence, leading to the aggravation of monsoon break conditions. In high aerosol-low rainfall regions extending across India, both in deficient and normal monsoon years, enhancements in aerosols levels, estimated as aerosol optical depth and absorbing aerosol index, acted to suppress daily rainfall anomaly, several times in a season, with lags of a few days. A higher frequency of prolonged rainfall breaks, longer than seven days, occurred in these regions. Previous studies point to monsoon rainfall weakening linked to an asymmetric inter-hemispheric energy balance change attributed to aerosols, and short-term rainfall enhancement from radiative effects of aerosols. In contrast, this study uncovers intraseasonal short-term rainfall suppression, from coincident aerosol forcing over the monsoon region, leading to aggravation of monsoon break spells. Prolonged and intense breaks in the monsoon in India are associated with rainfall deficits, which have been linked to reduced food grain production in the latter half of the twentieth century.
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41
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Patil N, Dave P, Venkataraman C. Contrasting influences of aerosols on cloud properties during deficient and abundant monsoon years. Sci Rep 2017; 7:44996. [PMID: 28337991 PMCID: PMC5364465 DOI: 10.1038/srep44996] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 02/17/2017] [Indexed: 11/25/2022] Open
Abstract
Direct aerosol radiative forcing facilitates the onset of Indian monsoon rainfall, based on synoptic scale fast responses acting over timescales of days to a month. Here, we examine relationships between aerosols and coincident clouds over the Indian subcontinent, using observational data from 2000 to 2009, from the core monsoon region. Season mean and daily timescales were considered. The correlation analyses of cloud properties with aerosol optical depth revealed that deficient monsoon years were characterized by more frequent and larger decreases in cloud drop size and ice water path, but increases in cloud top pressure, with increases in aerosol abundance. The opposite was observed during abundant monsoon years. The correlations of greater aerosol abundance, with smaller cloud drop size, lower evidence of ice processes and shallower cloud height, during deficient rainfall years, imply cloud inhibition; while those with larger cloud drop size, greater ice processes and a greater cloud vertical extent, during abundant rainfall years, suggest cloud invigoration. The study establishes that continental aerosols over India alter cloud properties in diametrically opposite ways during contrasting monsoon years. The mechanisms underlying these effects need further analysis.
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Affiliation(s)
- Nitin Patil
- Interdiciplinary program in Climate Studies, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Prashant Dave
- Interdiciplinary program in Climate Studies, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Chandra Venkataraman
- Interdiciplinary program in Climate Studies, Indian Institute of Technology Bombay, Powai, Mumbai, India
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
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43
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Improving our fundamental understanding of the role of aerosol-cloud interactions in the climate system. Proc Natl Acad Sci U S A 2016; 113:5781-90. [PMID: 27222566 DOI: 10.1073/pnas.1514043113] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The effect of an increase in atmospheric aerosol concentrations on the distribution and radiative properties of Earth's clouds is the most uncertain component of the overall global radiative forcing from preindustrial time. General circulation models (GCMs) are the tool for predicting future climate, but the treatment of aerosols, clouds, and aerosol-cloud radiative effects carries large uncertainties that directly affect GCM predictions, such as climate sensitivity. Predictions are hampered by the large range of scales of interaction between various components that need to be captured. Observation systems (remote sensing, in situ) are increasingly being used to constrain predictions, but significant challenges exist, to some extent because of the large range of scales and the fact that the various measuring systems tend to address different scales. Fine-scale models represent clouds, aerosols, and aerosol-cloud interactions with high fidelity but do not include interactions with the larger scale and are therefore limited from a climatic point of view. We suggest strategies for improving estimates of aerosol-cloud relationships in climate models, for new remote sensing and in situ measurements, and for quantifying and reducing model uncertainty.
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44
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Black carbon solar absorption suppresses turbulence in the atmospheric boundary layer. Proc Natl Acad Sci U S A 2016; 113:11794-11799. [PMID: 27702889 DOI: 10.1073/pnas.1525746113] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The introduction of cloud condensation nuclei and radiative heating by sunlight-absorbing aerosols can modify the thickness and coverage of low clouds, yielding significant radiative forcing of climate. The magnitude and sign of changes in cloud coverage and depth in response to changing aerosols are impacted by turbulent dynamics of the cloudy atmosphere, but integrated measurements of aerosol solar absorption and turbulent fluxes have not been reported thus far. Here we report such integrated measurements made from unmanned aerial vehicles (UAVs) during the CARDEX (Cloud Aerosol Radiative Forcing and Dynamics Experiment) investigation conducted over the northern Indian Ocean. The UAV and surface data reveal a reduction in turbulent kinetic energy in the surface mixed layer at the base of the atmosphere concurrent with an increase in absorbing black carbon aerosols. Polluted conditions coincide with a warmer and shallower surface mixed layer because of aerosol radiative heating and reduced turbulence. The polluted surface mixed layer was also observed to be more humid with higher relative humidity. Greater humidity enhances cloud development, as evidenced by polluted clouds that penetrate higher above the top of the surface mixed layer. Reduced entrainment of dry air into the surface layer from above the inversion capping the surface mixed layer, due to weaker turbulence, may contribute to higher relative humidity in the surface layer during polluted conditions. Measurements of turbulence are important for studies of aerosol effects on clouds. Moreover, reduced turbulence can exacerbate both the human health impacts of high concentrations of fine particles and conditions favorable for low-visibility fog events.
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45
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Relative influence of meteorological conditions and aerosols on the lifetime of mesoscale convective systems. Proc Natl Acad Sci U S A 2016; 113:7426-31. [PMID: 27313203 DOI: 10.1073/pnas.1601935113] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Using collocated measurements from geostationary and polar-orbital satellites over tropical continents, we provide a large-scale statistical assessment of the relative influence of aerosols and meteorological conditions on the lifetime of mesoscale convective systems (MCSs). Our results show that MCSs' lifetime increases by 3-24 h when vertical wind shear (VWS) and convective available potential energy (CAPE) are moderate to high and ambient aerosol optical depth (AOD) increases by 1 SD (1σ). However, this influence is not as strong as that of CAPE, relative humidity, and VWS, which increase MCSs' lifetime by 3-30 h, 3-27 h, and 3-30 h per 1σ of these variables and explain up to 36%, 45%, and 34%, respectively, of the variance of the MCSs' lifetime. AOD explains up to 24% of the total variance of MCSs' lifetime during the decay phase. This result is physically consistent with that of the variation of the MCSs' ice water content (IWC) with aerosols, which accounts for 35% and 27% of the total variance of the IWC in convective cores and anvil, respectively, during the decay phase. The effect of aerosols on MCSs' lifetime varies between different continents. AOD appears to explain up to 20-22% of the total variance of MCSs' lifetime over equatorial South America compared with 8% over equatorial Africa. Aerosols over the Indian Ocean can explain 20% of total variance of MCSs' lifetime over South Asia because such MCSs form and develop over the ocean. These regional differences of aerosol impacts may be linked to different meteorological conditions.
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Climatology Analysis of Aerosol Effect on Marine Water Cloud from Long-Term Satellite Climate Data Records. REMOTE SENSING 2016. [DOI: 10.3390/rs8040300] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Satellite retrieval of cloud condensation nuclei concentrations by using clouds as CCN chambers. Proc Natl Acad Sci U S A 2016; 113:5828-34. [PMID: 26944081 DOI: 10.1073/pnas.1514044113] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Quantifying the aerosol/cloud-mediated radiative effect at a global scale requires simultaneous satellite retrievals of cloud condensation nuclei (CCN) concentrations and cloud base updraft velocities (Wb). Hitherto, the inability to do so has been a major cause of high uncertainty regarding anthropogenic aerosol/cloud-mediated radiative forcing. This can be addressed by the emerging capability of estimating CCN and Wb of boundary layer convective clouds from an operational polar orbiting weather satellite. Our methodology uses such clouds as an effective analog for CCN chambers. The cloud base supersaturation (S) is determined by Wb and the satellite-retrieved cloud base drop concentrations (Ndb), which is the same as CCN(S). Validation against ground-based CCN instruments at Oklahoma, at Manaus, and onboard a ship in the northeast Pacific showed a retrieval accuracy of ±25% to ±30% for individual satellite overpasses. The methodology is presently limited to boundary layer not raining convective clouds of at least 1 km depth that are not obscured by upper layer clouds, including semitransparent cirrus. The limitation for small solar backscattering angles of <25° restricts the satellite coverage to ∼25% of the world area in a single day.
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Lin NH, Sayer AM, Wang SH, Loftus AM, Hsiao TC, Sheu GR, Hsu NC, Tsay SC, Chantara S. Interactions between biomass-burning aerosols and clouds over Southeast Asia: current status, challenges, and perspectives. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2014; 195:292-307. [PMID: 25085565 DOI: 10.1016/j.envpol.2014.06.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 06/08/2014] [Accepted: 06/28/2014] [Indexed: 06/03/2023]
Abstract
The interactions between aerosols, clouds, and precipitation remain among the largest sources of uncertainty in the Earth's energy budget. Biomass-burning aerosols are a key feature of the global aerosol system, with significant annually-repeating fires in several parts of the world, including Southeast Asia (SEA). SEA in particular provides a "natural laboratory" for these studies, as smoke travels from source regions downwind in which it is coupled to persistent stratocumulus decks. However, SEA has been under-exploited for these studies. This review summarizes previous related field campaigns in SEA, with a focus on the ongoing Seven South East Asian Studies (7-SEAS) and results from the most recent BASELInE deployment. Progress from remote sensing and modeling studies, along with the challenges faced for these studies, are also discussed. We suggest that improvements to our knowledge of these aerosol/cloud effects require the synergistic use of field measurements with remote sensing and modeling tools.
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Affiliation(s)
- Neng-Huei Lin
- Department of Atmospheric Sciences, National Central University, Chung-Li, Taiwan; Chemistry Department and Environmental Science Program, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand.
| | - Andrew M Sayer
- Goddard Space Flight Center, NASA, Greenbelt, MD, USA; Universities Space Research Association, Columbia, MD, USA
| | - Sheng-Hsiang Wang
- Department of Atmospheric Sciences, National Central University, Chung-Li, Taiwan
| | - Adrian M Loftus
- Goddard Space Flight Center, NASA, Greenbelt, MD, USA; Oak Ridge Associated Universities, Oak Ridge, TN, USA
| | - Ta-Chih Hsiao
- Graduate Institute of Environmental Engineering, National Central University, Chung-Li, Taiwan
| | - Guey-Rong Sheu
- Department of Atmospheric Sciences, National Central University, Chung-Li, Taiwan
| | | | - Si-Chee Tsay
- Goddard Space Flight Center, NASA, Greenbelt, MD, USA
| | - Somporn Chantara
- Chemistry Department and Environmental Science Program, Faculty of Science, Chiang Mai University, Chiang Mai, 50200, Thailand
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Dolgos G, Martins JV. Polarized Imaging Nephelometer for in situ airborne measurements of aerosol light scattering. OPTICS EXPRESS 2014; 22:21972-21990. [PMID: 25321572 DOI: 10.1364/oe.22.021972] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Global satellite remote sensing of aerosols requires in situ measurements to enable the calibration and validation of algorithms. In order to improve our understanding of light scattering by aerosol particles, and to enable routine in situ airborne measurements of aerosol light scattering, we have developed an instrument, called the Polarized Imaging Nephelometer (PI-Neph). We designed and built the PI-Neph at the Laboratory for Aerosols, Clouds and Optics (LACO) of the University of Maryland, Baltimore County (UMBC). This portable instrument directly measures the ambient scattering coefficient and phase matrix elements of aerosols, in the field or onboard an aircraft. The measured phase matrix elements are the P(11), phase function, and P(12). Lasers illuminate the sampled ambient air and aerosol, and a wide field of view camera detects scattered light in a scattering angle range of 3° to 176°. The PI-Neph measures an ensemble of particles, supplying the relevant quantity for satellite remote sensing, as opposed to particle-by-particle measurements that have other applications. Comparisons with remote sensing measurements will have to consider aircraft inlet effects. The PI-Neph first measured at a laser wavelength of 532nm, and was first deployed successfully in 2011 aboard the B200 aircraft of NASA Langley during the Development and Evaluation of satellite ValidatiOn Tools by Experimenters (DEVOTE) project. In 2013, we upgraded the PI-Neph to measure at 473nm, 532nm, and 671nm nearly simultaneously. LACO has deployed the PI-Neph on a number of airborne field campaigns aboard three different NASA aircraft. This paper describes the PI-Neph measurement approach and validation by comparing measurements of artificial spherical aerosols with Mie theory. We provide estimates of calibration uncertainties, which show agreement with the small residuals between measurements of P(11) and -P(12)/P(11) and Mie theory. We demonstrate the capability of the PI-Neph to measure ambient aerosol with two data sets from the Deep Convective Clouds and Chemistry (DC3) field campaign, from flights over Colorado in June 2012.
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Remer LA. Atmospheric science. Just add aerosols. Science 2014; 344:1089. [PMID: 24904141 DOI: 10.1126/science.1255398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Lorraine A Remer
- Joint Center for Earth Systems Technology, University of Maryland Baltimore County, 5523 Research Park Drive, Baltimore, MD 21228, USA.
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