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Wu D, Shi T, Niu X, Chen Z, Cui J, Chen Y, Zhang X, Liu J, Ji M, Wang X, Pu W. Seasonal to sub-seasonal variations of the Asian Tropopause Aerosols Layer affected by the deep convection, surface pollutants and precipitation. J Environ Sci (China) 2022; 114:53-65. [PMID: 35459514 DOI: 10.1016/j.jes.2021.07.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/09/2021] [Indexed: 06/14/2023]
Abstract
The Asian Tropopause Aerosols Layer (ATAL) refers to an accumulation of aerosols in the upper troposphere and lower stratosphere during boreal summer over Asia, which has a fundamental impact on the monsoon system and climate change. In this study, we primarily analyze the seasonal to sub-seasonal variations of the ATAL and the factors potentially influencing those variations based on MERRA2 reanalysis. The ability of the reanalysis to reproduce the ATAL is well validated by CALIPSO observations from May to October 2016. The results reveal that the ATAL has a synchronous spatiotemporal pattern with the development and movement of the Asian Summer Monsoon. Significant enhancement of ATAL intensity is found during the prevailing monsoon period of July-August, with two maxima centered over South Asia and the Arabian Peninsula. Owing to the fluctuations of deep convection, the ATAL shows an episodic variation on a timescale of 7-12 days. Attribution analysis indicates that deep convection dominates the variability of the ATAL with a contribution of 62.7%, followed by a contribution of 36.6% from surface pollutants. The impact of precipitation is limited. The ATAL further shows a clear diurnal variation: the peak of ATAL intensity occurs from 17:30 to 23:30 local time (LT), when the deep convection becomes strongest; the minimum ATAL intensity occurs around 8:30 LT owing to the weakened deep convection and photochemical reactions in clouds. The aerosol components of the ATAL show different spatiotemporal patterns and imply that black carbon and organic carbon come mainly from India, whereas sulfate comes mainly from China during the prevailing monsoon period.
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Affiliation(s)
- Dongyou Wu
- College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Tenglong Shi
- College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Xiaoying Niu
- College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Ziqi Chen
- College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Jiecan Cui
- College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Yang Chen
- College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Xueying Zhang
- Jilin Weather Modification Office, Changchun 130000, China
| | - Jun Liu
- College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Mingxia Ji
- College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China
| | - Xin Wang
- College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China; School of Earth System Science, Tianjin University, Tianjin 300072, China
| | - Wei Pu
- College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China.
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Origins and Spatial Distribution of Non-Pure Sulfate Particles (NSPs) in the Stratosphere Detected by the Balloon-Borne Light Optical Aerosols Counter (LOAC). ATMOSPHERE 2020. [DOI: 10.3390/atmos11101031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
While water and sulfuric acid droplets are the main component of stratospheric aerosols, measurements performed for about 30 years have shown that non-sulfate particles (NSPs) are also present. Such particles, released from the Earth mainly through volcanic eruptions, pollution or biomass burning, or coming from space, present a wide variety of compositions, sizes, and shapes. To better understand the origin of NSPs, we have performed measurements with the Light Optical Aerosol Counter (LOAC) during 151 flights under weather balloons in the 2013–2019 period reaching altitudes up to 35 km. Coupled with previous counting measurements conducted over the 2004–2011 period, the LOAC measurements indicate the presence of stratospheric layers of enhanced concentrations associated with NSPs, with a bimodal vertical repartition ranging between 17 and 30 km altitude. Such enhancements are not correlated with permanent meteor shower events. They may be linked to dynamical and photophoretic effects lifting and sustaining particles coming from the Earth. Besides, large particles, up to several tens of μm, were detected and present decreasing concentrations with increasing altitudes. All these particles can originate from Earth but also from meteoroid disintegrations and from the interplanetary dust cloud and comets.
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3
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Bian J, Li D, Bai Z, Li Q, Lyu D, Zhou X. Transport of Asian surface pollutants to the global stratosphere from the Tibetan Plateau region during the Asian summer monsoon. Natl Sci Rev 2020; 7:516-533. [PMID: 34692071 PMCID: PMC8288924 DOI: 10.1093/nsr/nwaa005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 01/16/2020] [Accepted: 01/18/2020] [Indexed: 11/13/2022] Open
Abstract
Due to its surrounding strong and deep Asian summer monsoon (ASM) circulation and active surface pollutant emissions, surface pollutants are transported to the stratosphere from the Tibetan Plateau region, which may have critical impacts on global climate through chemical, microphysical and radiative processes. This article reviews major recent advances in research regarding troposphere-stratosphere transport from the region of the Tibetan Plateau. Since the discovery of the total ozone valley over the Tibetan Plateau in summer from satellite observations in the early 1990s, new satellite-borne instruments have become operational and have provided significant new information on atmospheric composition. In addition, in situ measurements and model simulations are used to investigate deep convection and the ASM anticyclone, surface sources and pathways, atmospheric chemical transformations and the impact on global climate. Also challenges are discussed for further understanding critical questions on microphysics and microchemistry in clouds during the pathway to the global stratosphere over the Tibetan Plateau.
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Affiliation(s)
- Jianchun Bian
- Key Laboratory of Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dan Li
- Key Laboratory of Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Zhixuan Bai
- Key Laboratory of Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Qian Li
- Key Laboratory of Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Daren Lyu
- Key Laboratory of Middle Atmosphere and Global Environment Observation, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.,College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiuji Zhou
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, China Meteorological Administration, Beijing 100081, China
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4
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Niu H, Kang S, Gao W, Wang Y, Paudyal R. Vertical distribution of the Asian tropopause aerosols detected by CALIPSO. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 253:207-220. [PMID: 31310871 DOI: 10.1016/j.envpol.2019.06.111] [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: 04/04/2019] [Revised: 06/03/2019] [Accepted: 06/27/2019] [Indexed: 06/10/2023]
Abstract
Characterizing the vertical distribution of aerosol optical properties is crucial to reduce the uncertainty in quantifying the radiative forcing and climate effects of aerosols. The analysis of four-year (2007-2010) Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) lidar measurements revealed the existence of tropospheric aerosol layers associated with the Asian summer monsoon. The measurements of five typical aerosol optical and microphysical parameters were used to explore the properties, spatial/vertical distributions, annual evolution of tropopause aerosols over the South Asia region. Results extracted from various latitude-height and longitude-height cross sections of aerosol extinction coefficient at 532 and 1064 nm, backscatter coefficient at 532 nm, and depolarization ratio at 532 nm demonstrated that a large amount of aerosols vertically extended up to the tropopause (12 km) during the monsoon season over the north Arabian Sea, India, north Bay of Bengal, and equatorial Indian Ocean, finally reaching the southeast of the Tibetan Plateau. Convective transport associated with Asian summer monsoon is an important factor controlling the vertical distribution of tropopause aerosols. The evolution of aerosol scattering ratio at 532 nm indicated that from equatorial Indian Ocean to South Asia, there exists an upward tilting and ascending structure of the aerosols layer during the monsoon season, which typically indicates enhanced aerosols over the Asian monsoon region. Information on aerosol size distribution and detailed composition are needed for better understanding the nature and origin of this aerosol layer. Enhancement of the tropopause aerosols should be considered in the future studies in evaluating the regional or global climate systems. Further satellite observations of aerosols and in-situ observations are also urgently needed to diagnose this aerosol layer, which likely originate from anthropogenic emissions.
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Affiliation(s)
- Hewen Niu
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China; School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences (UCAS), Beijing, 10049, China.
| | - Wanni Gao
- School of International Cultural Exchange, Lanzhou University, Lanzhou, 730000, China
| | - Yuhang Wang
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Rukumesh Paudyal
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
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5
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Fadnavis S, Sabin TP, Roy C, Rowlinson M, Rap A, Vernier JP, Sioris CE. Elevated aerosol layer over South Asia worsens the Indian droughts. Sci Rep 2019; 9:10268. [PMID: 31311972 PMCID: PMC6635485 DOI: 10.1038/s41598-019-46704-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 07/04/2019] [Indexed: 11/19/2022] Open
Abstract
Droughts have become more severe and recurrent over the Indian sub-continent during the second half of the twentieth century, leading to more severe hydro-climatic and socio-economic impacts over one of the most densely populated parts of the world. So far, droughts have mostly been connected to circulation changes concomitant with the abnormal warming over the Pacific Ocean, prevalently known as "El Niño". Here, exploiting observational data sets and a series of dedicated sensitivity experiments, we show that the severity of droughts during El Niño is amplified (17%) by changes in aerosols. The model experiments simulate the transport of boundary layer aerosols from South Asian countries to higher altitudes (12-18 km) where they form the Asian Tropopause Aerosol Layer (ATAL) (~ 60-120°E, 20-40°N). During El Niño, the anomalous overturning circulation from the East Asian region further enriches the thickness of aerosol layers in the ATAL over the northern part of South Asia. The anomalous aerosol loading in the ATAL reduces insolation over the monsoon region, thereby exacerbating the severity of drought by further weakening the monsoon circulation. Future increases in industrial emissions from both East and South Asia will lead to a wider and thicker elevated aerosol layer in the upper troposphere, potentially amplifying the severity of droughts.
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Affiliation(s)
| | - T P Sabin
- Indian Institute of Tropical Meteorology, Pune, India
| | - Chaitri Roy
- Indian Institute of Tropical Meteorology, Pune, India
| | | | - Alexandru Rap
- School of Earth and Environment, University of Leeds, Leeds, UK
| | - Jean-Paul Vernier
- National Institute of Aerospace, Hampton, Virginia, United States
- NASA Langley Research Center, Hampton, Virginia, United States
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6
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Jain CD, Madhavan BL, Ratnam MV. Source apportionment of rainwater chemical composition to investigate the transport of lower atmospheric pollutants to the UTLS region. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 248:166-174. [PMID: 30784835 DOI: 10.1016/j.envpol.2019.02.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 01/22/2019] [Accepted: 02/03/2019] [Indexed: 05/09/2023]
Abstract
Efforts to understand the chemical composition of Asian Tropopause Aerosol Layer (ATAL) in the Upper Troposphere Lower Stratosphere (UTLS) region have revealed the dominance of nitrates in the samples collected from ATAL layer during the recent balloon campaigns. Potential sources have been thought to be in-situ formation, convective uplift and long-range transport. Rainwater chemical composition consists water-soluble chemical ions that are wet scavenged during rain events and gives an indirect indication of lower atmospheric pollutants. Keeping this in focus, total monsoon precipitation chemistry at Gadanki (13.5°N, 79.2°E) has been studied to understand the convective uplift possibilities to the UTLS region. About 32 rainwater samples collected during July to December 2017 were analysed for their chemical composition using Ion Chromatography. Total 16 ions comprising of 5 anions (F-, Cl-, NO3-, SO42- and PO43-), 6 cations (Na+, K+, Ca2+, Mg2+, Li+ and NH4+) and 5 trace metals (Cd2+, Ni2+, Co2+, Mn2+ and Zn2+) have been detected in different rainwater samples. Rainwater chemical composition data has been subjected to the Principal Component Analysis (PCA) to understand the correlations between different chemical species and to identify the possible sources of origin qualitatively. It has been observed that the chemical composition of the rainwater is very different from the chemical composition of the ATAL layer indicating non-existence of convective transport of lower level pollutants to the UTLS region at Gadanki. This observation is also well supported by the vertical distribution of CALIPSO derived aerosol types and ERA interim vertical pressure velocities during the sampling period.
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Affiliation(s)
- Chaithanya D Jain
- National Atmospheric Research Laboratory (NARL), Gadanki, 517 112, India.
| | - B L Madhavan
- National Atmospheric Research Laboratory (NARL), Gadanki, 517 112, India
| | - M Venkat Ratnam
- National Atmospheric Research Laboratory (NARL), Gadanki, 517 112, India
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7
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Yu P, Froyd KD, Portmann RW, Toon OB, Freitas SR, Bardeen CG, Brock C, Fan T, Gao R, Katich JM, Kupc A, Liu S, Maloney C, Murphy DM, Rosenlof KH, Schill G, Schwarz JP, Williamson C. Efficient In-Cloud Removal of Aerosols by Deep Convection. GEOPHYSICAL RESEARCH LETTERS 2019; 46:1061-1069. [PMID: 34219825 PMCID: PMC8243348 DOI: 10.1029/2018gl080544] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/19/2018] [Accepted: 12/22/2018] [Indexed: 06/11/2023]
Abstract
Convective systems dominate the vertical transport of aerosols and trace gases. The most recent in situ aerosol measurements presented here show that the concentrations of primary aerosols including sea salt and black carbon drop by factors of 10 to 10,000 from the surface to the upper troposphere. In this study we show that the default convective transport scheme in the National Science Foundation/Department of Energy Community Earth System Model results in a high bias of 10-1,000 times the measured aerosol mass for black carbon and sea salt in the middle and upper troposphere. A modified transport scheme, which considers aerosol activation from entrained air above the cloud base and aerosol-cloud interaction associated with convection, dramatically improves model agreement with in situ measurements suggesting that deep convection can efficiently remove primary aerosols. We suggest that models that fail to consider secondary activation may overestimate black carbon's radiative forcing by a factor of 2.
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Affiliation(s)
- Pengfei Yu
- Cooperative Institute for Research in Environmental SciencesUniversity of Colorado BoulderBoulderCOUSA
- Earth System Research LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
- Institute for Environment and Climate Research, Jinan UniversityGuangzhouChina
| | - Karl D. Froyd
- Cooperative Institute for Research in Environmental SciencesUniversity of Colorado BoulderBoulderCOUSA
- Earth System Research LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Robert W. Portmann
- Earth System Research LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Owen B. Toon
- Department of Atmospheric and Oceanic SciencesUniversity of Colorado BoulderBoulderCOUSA
- Laboratory for Atmospheric and Space PhysicsUniversity of Colorado BoulderBoulderCOUSA
| | - Saulo R. Freitas
- Goddard Earth Sciences Technology and ResearchUniversities Space Research AssociationColumbiaMDUSA
| | - Charles G. Bardeen
- Atmospheric Chemistry DivisionNational Center for Atmospheric ResearchBoulderCOUSA
| | - Charles Brock
- Earth System Research LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Tianyi Fan
- College of Global Change and Earth System ScienceBeijing Normal UniversityBeijingChina
| | - Ru‐Shan Gao
- Earth System Research LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Joseph M. Katich
- Cooperative Institute for Research in Environmental SciencesUniversity of Colorado BoulderBoulderCOUSA
- Earth System Research LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Agnieszka Kupc
- Cooperative Institute for Research in Environmental SciencesUniversity of Colorado BoulderBoulderCOUSA
- Earth System Research LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
- Now at the Faculty of PhysicsUniversity of ViennaViennaAustria
| | - Shang Liu
- School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefeiChina
| | - Christopher Maloney
- Department of Atmospheric and Oceanic SciencesUniversity of Colorado BoulderBoulderCOUSA
- Laboratory for Atmospheric and Space PhysicsUniversity of Colorado BoulderBoulderCOUSA
| | - Daniel M. Murphy
- Earth System Research LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Karen H. Rosenlof
- Earth System Research LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Gregory Schill
- Cooperative Institute for Research in Environmental SciencesUniversity of Colorado BoulderBoulderCOUSA
- Earth System Research LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Joshua P. Schwarz
- Earth System Research LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
| | - Christina Williamson
- Cooperative Institute for Research in Environmental SciencesUniversity of Colorado BoulderBoulderCOUSA
- Earth System Research LaboratoryNational Oceanic and Atmospheric AdministrationBoulderCOUSA
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8
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Chen Z, Bhartia PK, Loughman R, Colarco P, DeLand M. Improvement of stratospheric aerosol extinction retrieval from OMPS/LP using a new aerosol model. ATMOSPHERIC MEASUREMENT TECHNIQUES 2018; 11:6495-6509. [PMID: 33510818 PMCID: PMC7839985 DOI: 10.5194/amt-11-6495-2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The Ozone Mapping and Profiler Suite Limb Profiler (OMPS/LP) has been flying on the Suomi NPP satellite since October 2011. It is designed to produce ozone and aerosol vertical profiles at ~2 km vertical resolution over the entire sunlit globe. Aerosol extinction profiles are computed with Mie theory using radiances measured at 675 nm. The operational Version 1.0 (V1.0) aerosol extinction retrieval algorithm assumes a bimodal lognormal aerosol size distribution (ASD) whose parameters were derived by combining an in situ measurement of aerosol microphysics with the SAGE II aerosol extinction climatology. Internal analysis indicates that this bimodal lognormal ASD does not sufficiently explain the spectral dependence of LP measured radiances. In this paper we describe the derivation of an improved aerosol size distribution, designated Version 1.5 (V1.5), for the LP retrieval algorithm. The new ASD uses a gamma function distribution that is derived from Community Aerosol and Radiation Model for Atmospheres (CARMA) calculated results. A cumulative distribution fit derived from the gamma function ASD gives better agreement with CARMA results at small particle radii than bimodal or unimodal functions. The new ASD also explains the spectral dependence of LP measured radiances better than the V1.0 ASD. We find that the impact of our choice of ASD on the retrieved extinctions varies strongly with the underlying reflectivity of the scene. Initial comparisons with co-located extinction profiles retrieved at 676 nm from the SAGE III/ISS instrument show a significant improvement in agreement for the LP V1.5 retrievals. Zonal mean extinction profiles agree to within 10% between 19-29 km, and regression fits of collocated samples show improved correlation and reduced scatter compared to the V1.0 product. This improved agreement will motivate development of more sophisticated ASDs from CARMA results that incorporate latitude, altitude, and seasonal variations in aerosol properties.
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Affiliation(s)
- Zhong Chen
- Science Systems and Applications, Inc., Lanham, Maryland, 20706, USA
| | - Pawan K. Bhartia
- NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771, USA
| | - Robert Loughman
- Department of Atmospheric and Planetary Sciences, Hampton University, Hampton, Virginia, 23668, USA
| | - Peter Colarco
- NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771, USA
| | - Matthew DeLand
- Science Systems and Applications, Inc., Lanham, Maryland, 20706, USA
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Five-S-isotope evidence of two distinct mass-independent sulfur isotope effects and implications for the modern and Archean atmospheres. Proc Natl Acad Sci U S A 2018; 115:8541-8546. [PMID: 30082380 PMCID: PMC6112696 DOI: 10.1073/pnas.1803420115] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Anomalous sulfur isotopic compositions preserved in sedimentary rocks older than ∼2.5 billion years have been widely interpreted as the products of UV photolysis of sulfur dioxide in an anoxic atmosphere and used to track the history of primitive Earth and evolution of early life. In this study, we present strong observational evidence that there is an additional process that produces similar anomalous sulfur isotope signatures. This previously unknown origin not only offers a tool for quantifying the present-day atmospheric sulfur budget and evaluating its influences on climate and public health but also implies that anomalous sulfur isotopic compositions in some of the oldest rocks on Earth might have been produced in a way different from that previously thought. The signature of mass-independent fractionation of quadruple sulfur stable isotopes (S-MIF) in Archean rocks, ice cores, and Martian meteorites provides a unique probe of the oxygen and sulfur cycles in the terrestrial and Martian paleoatmospheres. Its mechanistic origin, however, contains some uncertainties. Even for the modern atmosphere, the primary mechanism responsible for the S-MIF observed in nearly all tropospheric sulfates has not been identified. Here we present high-sensitivity measurements of a fifth sulfur isotope, stratospherically produced radiosulfur, along with all four stable sulfur isotopes in the same sulfate aerosols and a suite of chemical species to define sources and mechanisms on a field observational basis. The five-sulfur-isotope and multiple chemical species analysis approach provides strong evidence that S-MIF signatures in tropospheric sulfates are concomitantly affected by two distinct processes: an altitude-dependent positive 33S anomaly, likely linked to stratospheric SO2 photolysis, and a negative 36S anomaly mainly associated with combustion. Our quadruple stable sulfur isotopic measurements in varying coal samples (formed in the Carboniferous, Permian, and Triassic periods) and in SO2 emitted from combustion display normal 33S and 36S, indicating that the observed negative 36S anomalies originate from a previously unknown S-MIF mechanism during combustion (likely recombination reactions) instead of coal itself. The basic chemical physics of S-MIF in both photolytic and thermal reactions and their interplay, which were not explored together in the past, may be another ingredient for providing deeper understanding of the evolution of Earth’s atmosphere and life’s origin.
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10
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Lelieveld J, Bourtsoukidis E, Brühl C, Fischer H, Fuchs H, Harder H, Hofzumahaus A, Holland F, Marno D, Neumaier M, Pozzer A, Schlager H, Williams J, Zahn A, Ziereis H. The South Asian monsoon-pollution pump and purifier. Science 2018; 361:270-273. [PMID: 29903882 DOI: 10.1126/science.aar2501] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 05/30/2018] [Indexed: 11/02/2022]
Abstract
Air pollution is growing fastest in monsoon-affected South Asia. During the dry winter monsoon, the fumes disperse toward the Indian Ocean, creating a vast pollution haze, but their fate during the wet summer monsoon has been unclear. We performed atmospheric chemistry measurements by aircraft in the Oxidation Mechanism Observations campaign, sampling the summer monsoon outflow in the upper troposphere between the Mediterranean and the Indian Ocean. The measurements, supported by model calculations, show that the monsoon sustains a remarkably efficient cleansing mechanism by which contaminants are rapidly oxidized and deposited to Earth's surface. However, some pollutants are lofted above the monsoon clouds and chemically processed in a reactive reservoir before being redistributed globally, including to the stratosphere.
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Affiliation(s)
- J Lelieveld
- Max Planck Institute for Chemistry, 55128 Mainz, Germany. .,The Cyprus Institute, 1645 Nicosia, Cyprus
| | | | - C Brühl
- Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - H Fischer
- Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - H Fuchs
- Institute for Energy and Climate Research, Research Center Jülich, 52425 Jülich, Germany
| | - H Harder
- Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - A Hofzumahaus
- Institute for Energy and Climate Research, Research Center Jülich, 52425 Jülich, Germany
| | - F Holland
- Institute for Energy and Climate Research, Research Center Jülich, 52425 Jülich, Germany
| | - D Marno
- Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - M Neumaier
- Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
| | - A Pozzer
- Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - H Schlager
- Institute of Atmospheric Physics, Germany Aerospace Center, 82234 Oberpfaffenhofen, Germany
| | - J Williams
- Max Planck Institute for Chemistry, 55128 Mainz, Germany.,The Cyprus Institute, 1645 Nicosia, Cyprus
| | - A Zahn
- Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
| | - H Ziereis
- Institute of Atmospheric Physics, Germany Aerospace Center, 82234 Oberpfaffenhofen, Germany
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11
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Lau WKM, Yuan C, Li Z. Origin, Maintenance and Variability of the Asian Tropopause Aerosol Layer (ATAL): The Roles of Monsoon Dynamics. Sci Rep 2018; 8:3960. [PMID: 29500395 PMCID: PMC5834455 DOI: 10.1038/s41598-018-22267-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 02/19/2018] [Indexed: 11/24/2022] Open
Abstract
Using NASA MERRA2 daily data, we investigated the origin, maintenance and variability of the Asian Tropopause Aerosol Layer (ATAL) in relation to variations of the Asia Monsoon Anticyclone (AMA) during the summer of 2008. During May-June, abundant quantities of carbon monoxide (CO), carbonaceous aerosols (CA) and dusts are found in the mid- and upper troposphere over India and China, arising from enhanced biomass burning emissions, as well as westerly transport from the Middle East deserts. During July-August, large quantities of dusts transported from the deserts are trapped and accumulate over the southern and eastern foothills of the Tibetan Plateau. Despite strong precipitation washout, ambient CO, CA and dust are lofted by orographically forced deep convection to great elevations, 12-16 km above sea level, via two key pathways over heavily polluted regions: a) the Himalayas-Gangetic Plain, and b) the Sichuan Basin. Upon entering the upper-troposphere-lower-stratosphere, the pollutants are capped by a stable layer near the tropopause, advected and dispersed by the anticyclonic circulation of AMA, forming the ATAL resembling a planetary-scale "double-stem chimney cloud". The development and variability of the ATAL are strongly linked to the seasonal march and intraseasonal (20-30 days and higher frequency) oscillations of the Asian monsoon.
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Affiliation(s)
- William K M Lau
- Earth System Science Interdisciplinary Center, U. of Maryland, College Park, MD, 20740, USA.
- Department of Atmospheric and Oceanic Sciences, U. of Maryland, College Park, MD, 20740, USA.
| | - Cheng Yuan
- Earth System Science Interdisciplinary Center, U. of Maryland, College Park, MD, 20740, USA
- School of Atmospheric Sciences, Nanjing University, Nanjing, China
| | - Zhanqing Li
- Earth System Science Interdisciplinary Center, U. of Maryland, College Park, MD, 20740, USA
- Department of Atmospheric and Oceanic Sciences, U. of Maryland, College Park, MD, 20740, USA
- State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing, China
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Efficient transport of tropospheric aerosol into the stratosphere via the Asian summer monsoon anticyclone. Proc Natl Acad Sci U S A 2017. [PMID: 28630285 DOI: 10.1073/pnas.1701170114] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An enhanced aerosol layer near the tropopause over Asia during the June-September period of the Asian summer monsoon (ASM) was recently identified using satellite observations. Its sources and climate impact are presently not well-characterized. To improve understanding of this phenomenon, we made in situ aerosol measurements during summer 2015 from Kunming, China, then followed with a modeling study to assess the global significance. The in situ measurements revealed a robust enhancement in aerosol concentration that extended up to 2 km above the tropopause. A climate model simulation demonstrates that the abundant anthropogenic aerosol precursor emissions from Asia coupled with rapid vertical transport associated with monsoon convection leads to significant particle formation in the upper troposphere within the ASM anticyclone. These particles subsequently spread throughout the entire Northern Hemispheric (NH) lower stratosphere and contribute significantly (∼15%) to the NH stratospheric column aerosol surface area on an annual basis. This contribution is comparable to that from the sum of small volcanic eruptions in the period between 2000 and 2015. Although the ASM contribution is smaller than that from tropical upwelling (∼35%), we find that this region is about three times as efficient per unit area and time in populating the NH stratosphere with aerosol. With a substantial amount of organic and sulfur emissions in Asia, the ASM anticyclone serves as an efficient smokestack venting aerosols to the upper troposphere and lower stratosphere. As economic growth continues in Asia, the relative importance of Asian emissions to stratospheric aerosol is likely to increase.
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Yu P, Toon OB, Bardeen CG, Bucholtz A, Rosenlof KH, Saide PE, Da Silva A, Ziemba LD, Thornhill KL, Jimenez JL, Campuzano-Jost P, Schwarz JP, Perring AE, Froyd KD, Wagner NL, Mills MJ, Reid JS. Surface dimming by the 2013 Rim Fire simulated by a sectional aerosol model. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2016; 121:7079-7087. [PMID: 27867782 PMCID: PMC5101842 DOI: 10.1002/2015jd024702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 05/18/2016] [Accepted: 06/01/2016] [Indexed: 06/02/2023]
Abstract
The Rim Fire of 2013, the third largest area burned by fire recorded in California history, is simulated by a climate model coupled with a size-resolved aerosol model. Modeled aerosol mass, number, and particle size distribution are within variability of data obtained from multiple-airborne in situ measurements. Simulations suggest that Rim Fire smoke may block 4-6% of sunlight energy reaching the surface, with a dimming efficiency around 120-150 W m-2 per unit aerosol optical depth in the midvisible at 13:00-15:00 local time. Underestimation of simulated smoke single scattering albedo at midvisible by 0.04 suggests that the model overestimates either the particle size or the absorption due to black carbon. This study shows that exceptional events like the 2013 Rim Fire can be simulated by a climate model with 1° resolution with overall good skill, although that resolution is still not sufficient to resolve the smoke peak near the source region.
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Affiliation(s)
- Pengfei Yu
- Laboratory for Atmospheric and Space Physics University of Colorado Boulder Boulder Colorado USA; Department of Atmospheric and Oceanic Sciences University of Colorado Boulder Boulder Colorado USA; Cooperative Institute for Research in Environmental Science University of Colorado Boulder Boulder Colorado USA; Earth System Research Laboratory National Oceanic and Atmospheric Administration Boulder Colorado USA
| | - Owen B Toon
- Laboratory for Atmospheric and Space Physics University of Colorado Boulder Boulder Colorado USA; Department of Atmospheric and Oceanic Sciences University of Colorado Boulder Boulder Colorado USA
| | - Charles G Bardeen
- Atmospheric Chemistry Observations and Modeling Laboratory National Center for Atmospheric Research Boulder Colorado USA
| | | | - Karen H Rosenlof
- Earth System Research Laboratory National Oceanic and Atmospheric Administration Boulder Colorado USA
| | - Pablo E Saide
- Atmospheric Chemistry Observations and Modeling Laboratory National Center for Atmospheric Research Boulder Colorado USA; Center for Global and Regional Environmental Research The University of Iowa Iowa City Iowa USA
| | | | | | | | - Jose-Luis Jimenez
- Cooperative Institute for Research in Environmental Science University of Colorado Boulder Boulder Colorado USA; Department of Chemistry and Biochemistry University of Colorado Boulder Boulder Colorado USA
| | - Pedro Campuzano-Jost
- Cooperative Institute for Research in Environmental Science University of Colorado Boulder Boulder Colorado USA; Department of Chemistry and Biochemistry University of Colorado Boulder Boulder Colorado USA
| | - Joshua P Schwarz
- Cooperative Institute for Research in Environmental Science University of Colorado Boulder Boulder Colorado USA; Earth System Research Laboratory National Oceanic and Atmospheric Administration Boulder Colorado USA
| | - Anne E Perring
- Cooperative Institute for Research in Environmental Science University of Colorado Boulder Boulder Colorado USA; Earth System Research Laboratory National Oceanic and Atmospheric Administration Boulder Colorado USA
| | - Karl D Froyd
- Cooperative Institute for Research in Environmental Science University of Colorado Boulder Boulder Colorado USA; Earth System Research Laboratory National Oceanic and Atmospheric Administration Boulder Colorado USA
| | - N L Wagner
- Cooperative Institute for Research in Environmental Science University of Colorado Boulder Boulder Colorado USA; Earth System Research Laboratory National Oceanic and Atmospheric Administration Boulder Colorado USA
| | - Michael J Mills
- Atmospheric Chemistry Observations and Modeling Laboratory National Center for Atmospheric Research Boulder Colorado USA
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Yu P, Toon OB, Bardeen CG, Mills MJ, Fan T, English JM, Neely RR. Evaluations of tropospheric aerosol properties simulated by the community earth system model with a sectional aerosol microphysics scheme. JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS 2015; 7:865-914. [PMID: 27668039 PMCID: PMC5020605 DOI: 10.1002/2014ms000421] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 05/18/2015] [Indexed: 05/16/2023]
Abstract
A sectional aerosol model (CARMA) has been developed and coupled with the Community Earth System Model (CESM1). Aerosol microphysics, radiative properties, and interactions with clouds are simulated in the size-resolving model. The model described here uses 20 particle size bins for each aerosol component including freshly nucleated sulfate particles, as well as mixed particles containing sulfate, primary organics, black carbon, dust, and sea salt. The model also includes five types of bulk secondary organic aerosols with four volatility bins. The overall cost of CESM1-CARMA is approximately ∼2.6 times as much computer time as the standard three-mode aerosol model in CESM1 (CESM1-MAM3) and twice as much computer time as the seven-mode aerosol model in CESM1 (CESM1-MAM7) using similar gas phase chemistry codes. Aerosol spatial-temporal distributions are simulated and compared with a large set of observations from satellites, ground-based measurements, and airborne field campaigns. Simulated annual average aerosol optical depths are lower than MODIS/MISR satellite observations and AERONET observations by ∼32%. This difference is within the uncertainty of the satellite observations. CESM1/CARMA reproduces sulfate aerosol mass within 8%, organic aerosol mass within 20%, and black carbon aerosol mass within 50% compared with a multiyear average of the IMPROVE/EPA data over United States, but differences vary considerably at individual locations. Other data sets show similar levels of comparison with model simulations. The model suggests that in addition to sulfate, organic aerosols also significantly contribute to aerosol mass in the tropical UTLS, which is consistent with limited data.
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Affiliation(s)
- Pengfei Yu
- Department of Atmospheric and Oceanic Sciences University of Colorado Boulder Colorado USA; Laboratory for Atmospheric and Space Physics University of Colorado Boulder Colorado USA
| | - Owen B Toon
- Department of Atmospheric and Oceanic Sciences University of Colorado Boulder Colorado USA; Laboratory for Atmospheric and Space Physics University of Colorado Boulder Colorado USA
| | | | - Michael J Mills
- National Center for Atmospheric Research Boulder Colorado USA
| | - Tianyi Fan
- Department of Atmospheric and Oceanic Sciences University of Colorado Boulder Colorado USA; Laboratory for Atmospheric and Space Physics University of Colorado Boulder Colorado USA; Now at College of Global Change and Earth System Science, Beijing Normal University Beijing China
| | - Jason M English
- Laboratory for Atmospheric and Space Physics University of Colorado Boulder Colorado USA
| | - Ryan R Neely
- National Center for Atmospheric Research Boulder Colorado USA; National Centre for Atmospheric Science and Institute of Climate and Atmospheric Science, School of the Earth and Environment, University of Leeds Leeds UK
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