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Pan T, He X, Bai Y, Li T, Gong F, Wang D. Satellite retrieval of the linear polarization components of the water-leaving radiance in open oceans. OPTICS EXPRESS 2023; 31:15917-15939. [PMID: 37157682 DOI: 10.1364/oe.489680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Atmospheric correction (AC) of polarized radiances acquired by polarization satellite sensors, remains a challenge due to the complex radiative transfer processes of the coupled ocean-atmosphere system. In this study, we proposed an innovative polarized AC algorithm built on the near-infrared band (PACNIR) with an emphasis on the retrieval of the linear polarization components of the water-leaving radiance in clear open oceans. This algorithm was based on the black ocean assumption in the near-infrared band and fitted polarized radiance measurements along multiple observation directions with nonlinear optimized processing. Our retrieval algorithm notably inverted the linearly polarized components of the water-leaving radiance and aerosol parameters. Compared with that of the simulated linear polarization components of the water-leaving radiance via the vector radiative transfer model for the studied sea regions, the mean absolute error of the PACNIR-retrieved linearly polarized components (nQw and nUw) exhibited a magnitude of 10-4, while the magnitude of that of the simulated nQw and nUw data was 10-3. Moreover, the PACNIR-retrieved aerosol optical thicknesses at 865 nm exhibited a mean absolute percentage error of approximately 30% relative to in situ values obtained from Aerosol Robotic Network-Ocean Color (AERONET-OC) sites. The PACNIR algorithm could facilitate AC of the polarized data provided by the next generation of multiangle polarization satellite ocean color sensors.
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2
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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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Jeong JH, Fan J, Homeyer CR, Hou Z. Understanding Hailstone Temporal Variability and Contributing Factors over the U.S. Southern Great Plains. JOURNAL OF CLIMATE 2020; 33:3947-3966. [PMID: 33967388 PMCID: PMC8097998 DOI: 10.1175/jcli-d-19-0606.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Hailstones are a natural hazard that pose a significant threat to property and are responsible for significant economic losses each year in the United States. Detailed understanding of their characteristics is essential to mitigate their impact. Identifying the dynamic and physical factors contributing to hail formation and hailstone sizes is of great importance to weather and climate prediction and policymakers. In this study, we have analyzed the temporal and spatial variabilities of severe hail occurrences over the U.S. southern Great Plains (SGP) states from 2004 to 2016 using two hail datasets: hail reports from the Storm Prediction Center and the newly developed radar-retrieved maximum expected size of hail (MESH). It is found that severe and significant severe hail occurrences have a considerable year-to-year temporal variability in the SGP region. The interannual variabilities have a strong correspondence with sea surface temperature anomalies over the northern Gulf of Mexico and there is no outlier. The year 2016 is identified as an outlier for the correlations with both El Niño-Southern Oscillation (ENSO) and aerosol loading. The correlations with ENSO and aerosol loading are not statistically robust to inclusion of the outlier 2016. Statistical analysis without the outlier 2016 shows that 1) aerosols that may be mainly from northern Mexico have the largest correlation with hail interannual variability among the three factors and 2) meteorological covariation does not significantly contribute to the high correlation. These analyses warrant further investigations of aerosol impacts on hail occurrence.
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Affiliation(s)
- Jong-Hoon Jeong
- Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington
| | - Jiwen Fan
- Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington
| | | | - Zhangshuan Hou
- Earth Systems Science Division, Pacific Northwest National Laboratory, Richland, Washington
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Chen D, Hu F, Nian G, Yang T. Deep Residual Learning for Nonlinear Regression. ENTROPY 2020; 22:e22020193. [PMID: 33285968 PMCID: PMC7516619 DOI: 10.3390/e22020193] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 01/31/2020] [Accepted: 02/04/2020] [Indexed: 11/16/2022]
Abstract
Deep learning plays a key role in the recent developments of machine learning. This paper develops a deep residual neural network (ResNet) for the regression of nonlinear functions. Convolutional layers and pooling layers are replaced by fully connected layers in the residual block. To evaluate the new regression model, we train and test neural networks with different depths and widths on simulated data, and we find the optimal parameters. We perform multiple numerical tests of the optimal regression model on multiple simulated data, and the results show that the new regression model behaves well on simulated data. Comparisons are also made between the optimal residual regression and other linear as well as nonlinear approximation techniques, such as lasso regression, decision tree, and support vector machine. The optimal residual regression model has better approximation capacity compared to the other models. Finally, the residual regression is applied into the prediction of a relative humidity series in the real world. Our study indicates that the residual regression model is stable and applicable in practice.
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Affiliation(s)
- Dongwei Chen
- School of Mathematical and Statistical Sciences, Clemson University, Clemson, SC 29641, USA; (D.C.); (T.Y.)
| | - Fei Hu
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
- College of Earth Science, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (F.H.); (G.N.); Tel.: +86-10-82995222 (F.H.); +86-15691032668 (G.N.)
| | - Guokui Nian
- College of Earth Science, University of Chinese Academy of Sciences, Beijing 100049, China
- State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
- Forecast Weather (Suzhou) Technology Co., Ltd., Suzhou 215000, China
- Correspondence: (F.H.); (G.N.); Tel.: +86-10-82995222 (F.H.); +86-15691032668 (G.N.)
| | - Tiantian Yang
- School of Mathematical and Statistical Sciences, Clemson University, Clemson, SC 29641, USA; (D.C.); (T.Y.)
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5
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Variability of orographic enhancement of precipitation in the Alpine region. Sci Rep 2019; 9:13352. [PMID: 31527776 PMCID: PMC6746858 DOI: 10.1038/s41598-019-49974-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 09/03/2019] [Indexed: 11/08/2022] Open
Abstract
Climate change impacts are non uniformly distributed over the globe. Mountains have a peculiar response to large scale variations, documented by elevation gradients of surface temperature increase observed over many mountain ranges in the last decades. Significant changes of precipitation are expected in the changing climate and orographic effects are important in determining the amount of rainfall at a given location. It thus becomes particularly important to understand how orographic precipitation responds to global warming and to anthropogenic forcing. Here, using a large rain gauge dataset over the European Alpine region, we show that the distribution of annual precipitation among the lowlands and the mountains has varied over time, with an increase of the precipitation at the high elevations compared to the low elevations starting in the mid 20 century and peaking in the 1980s. The simultaneous increase and peak of anthropogenic aerosol load is discussed as a possible source for this interdecadal change. These results provide new insights to further our understanding and improve predictions of anthropic effects on mountain precipitations, which are fundamental for water security and management.
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7
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Marrero-Ortiz W, Hu M, Du Z, Ji Y, Wang Y, Guo S, Lin Y, Gomez-Hermandez M, Peng J, Li Y, Secrest J, Zamora ML, Wang Y, An T, Zhang R. Formation and Optical Properties of Brown Carbon from Small α-Dicarbonyls and Amines. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:117-126. [PMID: 30499298 DOI: 10.1021/acs.est.8b03995] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Brown Carbon (BrC) aerosols scatter and absorb solar radiation, directly affecting the Earth's radiative budget. However, considerable uncertainty exists concerning the chemical mechanism leading to BrC formation and their optical properties. In this work, BrC particles were prepared from mixtures of small α-dicarbonyls (glyoxal and methylglyoxal) and amines (methylamine, dimethylamine, and trimethylamine). The absorption and scattering of BrC particles were measured using a photoacoustic extinctometer (405 and 532 nm), and the chemical composition of the α-dicarbonyl-amine mixtures was analyzed using orbitrap-mass spectrometry and thermal desorption-ion drift-chemical ionization mass spectrometry. The single scattering albedo for methylglyoxal-amine mixtures is smaller than that of glyoxal-amine mixtures and increases with the methyl substitution of amines. The mass absorption cross-section for methylglyoxal-amine mixtures is two times higher at 405 nm wavelength than that at 532 nm wavelength. The derived refractive indexes at the 405 nm wavelength are 1.40-1.64 for the real part and 0.002-0.195 for the imaginary part. Composition analysis in the α-dicarbonyl-amine mixtures reveals N-heterocycles as the dominant products, which are formed via multiple steps involving nucleophilic attack, steric hindrance, and dipole-dipole interaction between α-dicarbonyls and amines. BrC aerosols, if formed from the particle-phase reaction of methylglyoxal with methylamine, likely contribute to atmospheric warming.
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Affiliation(s)
- Wilmarie Marrero-Ortiz
- Department of Chemistry , Texas A&M University , College Station , Texas 77840 , United States
| | - Min Hu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering , Peking University , Beijing 100871 , China
| | - Zhuofei Du
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering , Peking University , Beijing 100871 , China
| | - Yuemeng Ji
- Center for Urban Transport Emission Research & State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering , Nankai University , Tianjin , 300071 , China
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control , Guangdong University of Technology , Guangzhou 510006 , China
| | - Yujue Wang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering , Peking University , Beijing 100871 , China
| | - Song Guo
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering , Peking University , Beijing 100871 , China
| | - Yun Lin
- Department of Atmospheric Sciences , Texas A&M University , College Station , Texas 77843 , United States
| | - Mario Gomez-Hermandez
- Department of Chemistry , Texas A&M University , College Station , Texas 77840 , United States
- Department of Chemistry and Biochemistry , Florida International University , Miami , Florida 33199 , United States
| | - Jianfei Peng
- Department of Atmospheric Sciences , Texas A&M University , College Station , Texas 77843 , United States
| | - Yixin Li
- Department of Chemistry , Texas A&M University , College Station , Texas 77840 , United States
| | - Jeremiah Secrest
- Department of Chemistry , Texas A&M University , College Station , Texas 77840 , United States
| | - Misti L Zamora
- Department of Atmospheric Sciences , Texas A&M University , College Station , Texas 77843 , United States
- Environmental Health & Engineering, Johns Hopkins School of Public Health , Johns Hopkins University , Baltimore , Maryland 21218 , United States
| | - Yuan Wang
- Division of Geological and Planetary Sciences , California Institute of Technology , Pasadena , California 91125 , United States
| | - Taicheng An
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control , Guangdong University of Technology , Guangzhou 510006 , China
| | - Renyi Zhang
- Department of Chemistry , Texas A&M University , College Station , Texas 77840 , United States
- Department of Atmospheric Sciences , Texas A&M University , College Station , Texas 77843 , United States
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Non-Monotonic Dependencies of Cloud Microphysics and Precipitation on Aerosol Loading in Deep Convective Clouds: A Case Study Using the WRF Model with Bin Microphysics. ATMOSPHERE 2018. [DOI: 10.3390/atmos9110434] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aerosol-cloud-precipitation interactions in deep convective clouds are investigated through numerical simulations of a heavy precipitation event over South Korea on 15–16 July 2017. The Weather Research and Forecasting model with a bin microphysics scheme is used, and various aerosol number concentrations in the range N0 = 50–12,800 cm−3 are considered. Precipitation amount changes non-monotonically with increasing aerosol loading, with a maximum near a moderate aerosol loading (N0 = 800 cm−3). Up to this optimal value, an increase in aerosol number concentration results in a greater quantity of small droplets formed by nucleation, increasing the number of ice crystals. Ice crystals grow into snow particles through deposition and riming, leading to enhanced melting and precipitation. Beyond the optimal value, a greater aerosol loading enhances generation of ice crystals while the overall growth of ice hydrometeors through deposition stagnates. Subsequently, the riming rate decreases because of the smaller size of snow particles and supercooled drops, leading to a decrease in ice melting and a slight suppression of precipitation. As aerosol loading increases, cold pool and low-level convergence strengthen monotonically, but cloud development is more strongly affected by latent heating and convection within the system that is non-monotonically reinforced.
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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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10
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Sarangi C, Kanawade VP, Tripathi SN, Thomas A, Ganguly D. Aerosol-induced intensification of cooling effect of clouds during Indian summer monsoon. Nat Commun 2018; 9:3754. [PMID: 30217981 PMCID: PMC6138698 DOI: 10.1038/s41467-018-06015-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 08/01/2018] [Indexed: 11/08/2022] Open
Abstract
Measurements and models show that enhanced aerosol concentrations can modify macro- and micro-physical properties of clouds. Here, we examine the effect of aerosols on continental mesoscale convective cloud systems during the Indian summer monsoon and find that these aerosol-cloud interactions have a net cooling effect at the surface and the top-of-atmosphere. Long-term (2002-2016) satellite data provide evidence of aerosol-induced cloud invigoration effect (AIvE) during the Indian summer monsoon. The AIvE leads to enhanced formation of thicker stratiform anvil clouds at higher altitudes. These AIvE-induced stratiform anvil clouds are also relatively brighter because of the presence of smaller sized ice particles. As a result, AIvE-induced increase in shortwave cloud radiative forcing is much larger than longwave cloud radiative forcing leading to the intensified net cooling effect of clouds over the Indian summer monsoon region. Such aerosol-induced cooling could subsequently decrease the surface diurnal temperature range and have significant feedbacks on lower tropospheric turbulence in a warmer and polluted future scenario.
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Affiliation(s)
- Chandan Sarangi
- Department of Civil Engineering and Centre for Environmental Science and Engineering, Indian Institute of Technology Kanpur, Kanpur, 208016, UttarPradesh, India
- Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Vijay P Kanawade
- Centre for Earth, Ocean & Atmospheric Sciences, University of Hyderabad, Hyderabad, Telangana, 500046, India.
| | - Sachchida N Tripathi
- Department of Civil Engineering and Centre for Environmental Science and Engineering, Indian Institute of Technology Kanpur, Kanpur, 208016, UttarPradesh, India.
| | - Abin Thomas
- Centre for Earth, Ocean & Atmospheric Sciences, University of Hyderabad, Hyderabad, Telangana, 500046, India
| | - Dilip Ganguly
- Centre for Atmospheric Sciences, Indian Institute of Technology Delhi, New Delhi, 110016, India
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11
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Role of Water Vapor Content in the Effects of Aerosol on the Electrification of Thunderstorms: A Numerical Study. ATMOSPHERE 2016. [DOI: 10.3390/atmos7100137] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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12
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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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Tao WK, Li X. The relationship between latent heating, vertical velocity, and precipitation processes: The impact of aerosols on precipitation in organized deep convective systems. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2016; 121:6299-6320. [PMID: 32818125 PMCID: PMC7430198 DOI: 10.1002/2015jd024267] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A high-resolution, two-dimensional cloud-resolving model with spectral-bin microphysics is used to study the impact of aerosols on precipitation processes in both a tropical oceanic and a midlatitude continental squall line with regard to three processes: latent heating (LH), cold pool dynamics and ice microphysics. Evaporative cooling in the lower troposphere is found to enhance rainfall in low cloud condensation nuclei (CCN) concentration scenarios in the developing stages of a midlatitude convective precipitation system. In contrast, the tropical case produced more rainfall under high CCN concentrations. Both cold pools and low-level convergence are stronger for those configurations having enhanced rainfall. Nevertheless, latent heat release is stronger (especially after initial precipitation) in the scenarios having more rainfall in both the tropical and midlatitude environment. Sensitivity tests are performed to examine the impact of ice and evaporative cooling on the relationship between aerosols, LH and precipitation processes. The results show that evaporative cooling is important for cold pool strength and rain enhancement in both cases. However, ice microphysics play a larger role in the midlatitude case compared to the tropical. Detailed analysis of the vertical velocity governing equation shows that temperature buoyancy can enhance updrafts/downdrafts in the middle/lower troposphere in the convective core region; however, the vertical pressure gradient force (PGF) is the same order and acts in the opposite direction. Water loading is small but on the same order as the net PGF-temperature buoyancy forcing. The balance among these terms determines the intensity of convection.
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Affiliation(s)
- Wei-Kuo Tao
- Mesoscale Atmospheric Processes Laboratory, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - Xiaowen Li
- Mesoscale Atmospheric Processes Laboratory, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA
- Goddard Earth Sciences Technology and Research, Morgan State University, Baltimore, MD, 21250, USA
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14
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Zhang GJ, Song X. Parameterization of Microphysical Processes in Convective Clouds in Global Climate Models. ACTA ACUST UNITED AC 2016. [DOI: 10.1175/amsmonographs-d-15-0015.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The microphysical processes inside convective clouds play an important role in climate. They directly control the amount of detrainment of cloud hydrometeor and water vapor from updrafts. The detrained water substance in turn affects the anvil cloud formation, upper-tropospheric water vapor distribution, and thus the atmospheric radiation budget. In global climate models, convective parameterization schemes have not explicitly represented microphysics processes in updrafts until recently. In this paper, the authors provide a review of existing schemes for convective microphysics parameterization. These schemes are broadly divided into three groups: tuning-parameter-based schemes (simplest), single-moment schemes, and two-moment schemes (most comprehensive). Common weaknesses of the tuning-parameter-based and single-moment schemes are outlined. Examples are presented from one of the two-moment schemes to demonstrate the performance of the scheme in simulating the hydrometeor distribution in convection and its representation of the effect of aerosols on convection.
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Affiliation(s)
- Guang J. Zhang
- Scripps Institution of Oceanography, La Jolla, California
| | - Xiaoliang Song
- Scripps Institution of Oceanography, La Jolla, California
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15
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Bae SY, Jeong JI, Park RJ, Lim KSS, Hong SY. Weekly variability of precipitation induced by anthropogenic aerosols: A case study in Korea in summer 2004. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 541:1531-1539. [PMID: 26479919 DOI: 10.1016/j.scitotenv.2015.10.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 09/28/2015] [Accepted: 10/06/2015] [Indexed: 06/05/2023]
Abstract
We examine the effect of anthropogenic aerosols on the weekly variability of precipitation in Korea in summer 2004 by using Weather Research and Forecasting (WRF) and Community Multiscale Air Quality (CMAQ) models. We conduct two WRF simulations including a baseline simulation with empirically based cloud condensation nuclei (CCN) number concentrations and a sensitivity simulation with our implementation to account for the effect of aerosols on CCN number concentrations. The first simulation underestimates observed precipitation amounts, particularly in northeastern coastal areas of Korea, whereas the latter shows higher precipitation amounts that are in better agreement with the observations. In addition, the sensitivity model with the aerosol effects reproduces the observed weekly variability, particularly for precipitation frequency with a high R at 0.85, showing 20% increase of precipitation events during the weekend than those during weekdays. We find that the aerosol effect results in higher CCN number concentrations during the weekdays and a three-fold increase of the cloud water mixing ratio through enhanced condensation. As a result, the amount of warm rain is generally suppressed because of the low auto-conversion process from cloud water to rain water under high aerosol conditions. The inefficient conversion, however, leads to higher vertical development of clouds in the mid-atmosphere with stronger updrafts in the sensitivity model, which increases by 21% cold-phase hydrometeors including ice, snow, and graupel relative to the baseline model and ultimately results in higher precipitation amounts in summer.
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Affiliation(s)
- Soo Ya Bae
- Korea Institute of Atmospheric Prediction Systems, Seoul, South Korea
| | - Jaein I Jeong
- School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea.
| | - Rokjin J Park
- School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea.
| | | | - Song-You Hong
- Korea Institute of Atmospheric Prediction Systems, Seoul, South Korea; Department of Atmospheric Science, Yonsei University, Seoul, South Korea
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Application of an Online-Coupled Regional Climate Model, WRF-CAM5, over East Asia for Examination of Ice Nucleation Schemes: Part II. Sensitivity to Heterogeneous Ice Nucleation Parameterizations and Dust Emissions. CLIMATE 2015. [DOI: 10.3390/cli3030753] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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17
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Zhang R, Wang G, Guo S, Zamora ML, Ying Q, Lin Y, Wang W, Hu M, Wang Y. Formation of urban fine particulate matter. Chem Rev 2015; 115:3803-55. [PMID: 25942499 DOI: 10.1021/acs.chemrev.5b00067] [Citation(s) in RCA: 497] [Impact Index Per Article: 55.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Renyi Zhang
- §State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, People's Republic of China
| | | | - Song Guo
- §State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, People's Republic of China
| | | | | | | | | | - Min Hu
- §State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, People's Republic of China
| | - Yuan Wang
- #Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91125, United States
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Asian pollution climatically modulates mid-latitude cyclones following hierarchical modelling and observational analysis. Nat Commun 2015; 5:3098. [PMID: 24448316 DOI: 10.1038/ncomms4098] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 12/12/2013] [Indexed: 11/08/2022] Open
Abstract
Increasing levels of anthropogenic aerosols in Asia have raised considerable concern regarding its potential impact on the global atmosphere, but the magnitude of the associated climate forcing remains to be quantified. Here, using a novel hierarchical modelling approach and observational analysis, we demonstrate modulated mid-latitude cyclones by Asian pollution over the past three decades. Regional and seasonal simulations using a cloud-resolving model show that Asian pollution invigorates winter cyclones over the northwest Pacific, increasing precipitation by 7% and net cloud radiative forcing by 1.0 W m(-2) at the top of the atmosphere and by 1.7 W m(-2) at the Earth's surface. A global climate model incorporating the diabatic heating anomalies from Asian pollution produces a 9% enhanced transient eddy meridional heat flux and reconciles a decadal variation of mid-latitude cyclones derived from the Reanalysis data. Our results unambiguously reveal a large impact of the Asian pollutant outflows on the global general circulation and climate.
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Xu W, Gomez-Hernandez M, Guo S, Secrest J, Marrero-Ortiz W, Zhang AL, Zhang R. Acid-catalyzed reactions of epoxides for atmospheric nanoparticle growth. J Am Chem Soc 2014; 136:15477-80. [PMID: 25338124 DOI: 10.1021/ja508989a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Although new particle formation accounts for about 50% of the global aerosol production in the troposphere, the chemical species and mechanism responsible for the growth of freshly nucleated nanoparticles remain largely uncertain. Here we show large size growth when sulfuric acid nanoparticles of 4-20 nm are exposed to epoxide vapors, dependent on the particle size and relative humidity. Composition analysis of the nanoparticles after epoxide exposure reveals the presence of high molecular weight organosulfates and polymers, indicating the occurrence of acid-catalyzed reactions of epoxides. Our results suggest that epoxides play an important role in the growth of atmospheric newly nucleated nanoparticles, considering their large formation yields from photochemical oxidation of biogenic volatile organic compounds.
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Affiliation(s)
- Wen Xu
- Department of Chemistry and Department of Atmospheric Sciences, Texas A&M University , College Station, Texas 77843, United States
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Assessing the effects of anthropogenic aerosols on Pacific storm track using a multiscale global climate model. Proc Natl Acad Sci U S A 2014; 111:6894-9. [PMID: 24733923 DOI: 10.1073/pnas.1403364111] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Atmospheric aerosols affect weather and global general circulation by modifying cloud and precipitation processes, but the magnitude of cloud adjustment by aerosols remains poorly quantified and represents the largest uncertainty in estimated forcing of climate change. Here we assess the effects of anthropogenic aerosols on the Pacific storm track, using a multiscale global aerosol-climate model (GCM). Simulations of two aerosol scenarios corresponding to the present day and preindustrial conditions reveal long-range transport of anthropogenic aerosols across the north Pacific and large resulting changes in the aerosol optical depth, cloud droplet number concentration, and cloud and ice water paths. Shortwave and longwave cloud radiative forcing at the top of atmosphere are changed by -2.5 and +1.3 W m(-2), respectively, by emission changes from preindustrial to present day, and an increased cloud top height indicates invigorated midlatitude cyclones. The overall increased precipitation and poleward heat transport reflect intensification of the Pacific storm track by anthropogenic aerosols. Hence, this work provides, for the first time to the authors' knowledge, a global perspective of the effects of Asian pollution outflows from GCMs. Furthermore, our results suggest that the multiscale modeling framework is essential in producing the aerosol invigoration effect of deep convective clouds on a global scale.
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Xu W, Zhang R. A theoretical study of hydrated molecular clusters of amines and dicarboxylic acids. J Chem Phys 2013; 139:064312. [DOI: 10.1063/1.4817497] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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22
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Yin Y, Chen Q, Jin L, Chen B, Zhu S, Zhang X. The effects of deep convection on the concentration and size distribution of aerosol particles within the upper troposphere: A case study. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012jd017827] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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23
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Ellison D, N Futter M, Bishop K. On the forest cover–water yield debate: from demand- to supply-side thinking. GLOBAL CHANGE BIOLOGY 2012; 18:806-820. [PMCID: PMC3597246 DOI: 10.1111/j.1365-2486.2011.02589.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 10/17/2011] [Accepted: 11/01/2011] [Indexed: 05/23/2023]
Abstract
Several major articles from the past decade and beyond conclude the impact of reforestation or afforestation on water yield is negative: additional forest cover will reduce and removing forests will raise downstream water availability. A second group of authors argue the opposite: planting additional forests should raise downstream water availability and intensify the hydrologic cycle. Obtaining supporting evidence for this second group of authors has been more difficult due to the larger scales at which the positive effects of forests on the water cycle may be seen. We argue that forest cover is inextricably linked to precipitation. Forest-driven evapotranspiration removed from a particular catchment contributes to the availability of atmospheric moisture vapor and its cross-continental transport, raising the likelihood of precipitation events and increasing water yield, in particular in continental interiors more distant from oceans. Seasonal relationships heighten the importance of this phenomenon. We review the arguments from different scales and perspectives. This clarifies the generally beneficial relationship between forest cover and the intensity of the hydrologic cycle. While evidence supports both sides of the argument – trees can reduce runoff at the small catchment scale – at larger scales, trees are more clearly linked to increased precipitation and water availability. Progressive deforestation, land conversion from forest to agriculture and urbanization have potentially negative consequences for global precipitation, prompting us to think of forest ecosystems as global public goods. Policy-making attempts to measure product water footprints, estimate the value of ecosystem services, promote afforestation, develop drought mitigation strategies and otherwise manage land use must consider the linkage of forests to the supply of precipitation.
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Affiliation(s)
- David Ellison
- Institute for World Economics, Hungarian Academy of Sciences1014 HU Budapest, Hungary
- Department of Forest Ecology, Swedish University of Agricultural Sciences90183 SE Umeå, Sweden
- Department of Social and Economic Geography, 90187 Umeå UniversityUmeå, Sweden
| | - Martyn N Futter
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences75007 SE Uppsala, Sweden
| | - Kevin Bishop
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences75007 SE Uppsala, Sweden
- Department of Earth Sciences, Uppsala University75236 SE Uppsala, Sweden
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Fan J, Leung LR, Li Z, Morrison H, Chen H, Zhou Y, Qian Y, Wang Y. Aerosol impacts on clouds and precipitation in eastern China: Results from bin and bulk microphysics. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd016537] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Zhang R, Khalizov A, Wang L, Hu M, Xu W. Nucleation and growth of nanoparticles in the atmosphere. Chem Rev 2011; 112:1957-2011. [PMID: 22044487 DOI: 10.1021/cr2001756] [Citation(s) in RCA: 481] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Renyi Zhang
- Department of Atmospheric Sciences and Department of Chemistry, Center for Atmospheric Chemistry and Environment, Texas A&M University, College Station, Texas 77843, USA.
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Fan J, Comstock JM, Ovchinnikov M, McFarlane SA, McFarquhar G, Allen G. Tropical anvil characteristics and water vapor of the tropical tropopause layer: Impact of heterogeneous and homogeneous freezing parameterizations. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jd012696] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Fan J, Yuan T, Comstock JM, Ghan S, Khain A, Leung LR, Li Z, Martins VJ, Ovchinnikov M. Dominant role by vertical wind shear in regulating aerosol effects on deep convective clouds. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2009jd012352] [Citation(s) in RCA: 235] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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29
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Khain AP, Leung LR, Lynn B, Ghan S. Effects of aerosols on the dynamics and microphysics of squall lines simulated by spectral bin and bulk parameterization schemes. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2009jd011902] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Khain A, Lynn B. Simulation of a supercell storm in clean and dirty atmosphere using weather research and forecast model with spectral bin microphysics. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2009jd011827] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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31
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Li G, Wang Y, Lee KH, Diao Y, Zhang R. Impacts of aerosols on the development and precipitation of a mesoscale squall line. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd011581] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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32
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Qian Y, Gong D, Fan J, Leung LR, Bennartz R, Chen D, Wang W. Heavy pollution suppresses light rain in China: Observations and modeling. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd011575] [Citation(s) in RCA: 225] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Xue H, Khalizov AF, Wang L, Zheng J, Zhang R. Effects of dicarboxylic acid coating on the optical properties of soot. Phys Chem Chem Phys 2009; 11:7869-75. [PMID: 19727494 DOI: 10.1039/b904129j] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Soot is a major component of atmospheric aerosols responsible for absorption of visible solar radiation. Internal mixing of soot with transparent materials can enhance its ability to absorb and scatter light, resulting in a larger role of soot in climate forcing. We have investigated the absorption and scattering of visible light (532 nm) by soot aerosol internally mixed with succinic and glutaric acids using a combination of a cavity ring-down spectrometer and an integrating nephelometer. The measurements were performed for flame-generated soot aerosol with well-characterized morphology and mixing state in the particle size range from 155 to 320 nm. Thin coatings of dicarboxylic acids on soot aggregates (with a mass fraction of 0.1-0.4) enhance significantly light scattering (up to 3.8 fold) and slightly light absorption (less than 1.2 fold). Cycling the coated soot aerosol through high relative humidity (humidified to 90% RH and then dried to 5% RH) promotes further increase in light absorption and scattering for soot internally mixed with glutaric acid, but not for soot mixed with succinic acid. The larger effect of glutaric acid on light absorption and scattering is caused by the irreversible restructuring of soot aggregates induced by the coating material. Our results indicate that the enhancement in the optical properties of soot by transparent coatings is strongly related to the ability of the coating materials to change the morphology of soot aggregates.
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Affiliation(s)
- Huaxin Xue
- Department of Atmospheric Sciences and Department of Chemistry, Texas A&M University, College Station, TX 77843, USA
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Bao Z, Wen Z, Wu R. Variability of aerosol optical depth over east Asia and its possible impacts. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd010603] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Fan J, Ovtchinnikov M, Comstock JM, McFarlane SA, Khain A. Ice formation in Arctic mixed-phase clouds: Insights from a 3-D cloud-resolving model with size-resolved aerosol and cloud microphysics. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd010782] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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36
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Li G, Wang Y, Zhang R. Implementation of a two-moment bulk microphysics scheme to the WRF model to investigate aerosol-cloud interaction. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009361] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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37
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Fan J, Zhang R, Tao WK, Mohr KI. Effects of aerosol optical properties on deep convective clouds and radiative forcing. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009257] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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