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Tian Y, Pan X, Yan J, Lin Q, Sun Y, Li M, Xie C, Uno I, Liu H, Wang Z, Fu P, Wang Z. Size Distribution and Depolarization Properties of Aerosol Particles over the Northwest Pacific and Arctic Ocean from Shipborne Measurements during an R/V Xuelong Cruise. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:7984-7995. [PMID: 31257870 DOI: 10.1021/acs.est.9b00245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Atmospheric aerosols over polar regions have attracted considerable attention for their pivotal effects on climate change. In this study, temporospatial variations in single-particle-based depolarization ratios (δ: s-polarized component divided by the total backward scattering intensity) were studied over the Northwest Pacific and the Arctic Ocean using an optical particle counter with a depolarization module. The δ value of aerosols was 0.06 ± 0.01 for the entire observation period, 61 ± 10% lower than the observations for coastal Japan (0.12 ± 0.02) ( Pan et al. Atmos. Chem. Phys. 2016 , 16 , 9863 - 9873 ) and inland China (0.19 ± 0.02) ( Tian et al. Atmos. Chem. Phys. 2018 , 18 , 18203 - 18217 ) in summer. The volume concentration showed two dominant size modes at 0.9 and 2 μm. The supermicrometer particles were mostly related to sea-salt aerosols with a δ value of 0.09 over marine polar areas, ∼22% larger than in the low-latitude region because of differences in chemical composition and dry air conditions. The δ values for fine particles (<1 μm) were 0.05 ± 0.1, 50% lower than inland anthropogenic pollutants, mainly because of the complex mixtures of submicrometer sea salts. High particle concentrations in the Arctic Ocean could mostly be attributed to the strong marine emission of sea salt associated with deep oceanic cyclones, whereas long-range transport pollutants from the continent were among the primary causes of high particle concentrations in the Northwest Pacific region.
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Affiliation(s)
- Yu Tian
- 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 and Planetary Sciences , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Xiaole Pan
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics , Chinese Academy of Sciences , Beijing 100029 , China
| | - Jinpei Yan
- Third Institute of Oceanography , Ministry of Natural Resources, Xiamen 361005 , China
| | - Qi Lin
- Third Institute of Oceanography , Ministry of Natural Resources, Xiamen 361005 , China
| | - Yele Sun
- 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 and Planetary Sciences , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Mei Li
- Institute of Mass Spectrometer and Atmospheric Environment , Jinan University , Guangzhou 510632 , China
| | - Conghui Xie
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics , Chinese Academy of Sciences , Beijing 100029 , China
| | - Itsushi Uno
- Research Institute for Applied Mechanics , Kyushu University , Kasuga 816-8580 , Japan
| | - Hang Liu
- 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 and Planetary Sciences , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Zhe Wang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics , Chinese Academy of Sciences , Beijing 100029 , China
- Research Institute for Applied Mechanics , Kyushu University , Kasuga 816-8580 , Japan
| | - Pingqing Fu
- Institute of Surface-Earth System Sciences , Tianjin University , Tianjin 300072 , China
| | - Zifa Wang
- 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 and Planetary Sciences , University of Chinese Academy of Sciences , Beijing 100049 , China
- Center for Excellence in Regional Atmospheric Environment , Chinese Academy of Science , Xiamen 361021 , China
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Kim MH, Omar AH, Tackett JL, Vaughan MA, Winker DM, Trepte CR, Hu Y, Liu Z, Poole LR, Pitts MC, Kar J, Magill BE. The CALIPSO Version 4 Automated Aerosol Classification and Lidar Ratio Selection Algorithm. ATMOSPHERIC MEASUREMENT TECHNIQUES 2018; 11:6107-6135. [PMID: 31921372 PMCID: PMC6951257 DOI: 10.5194/amt-11-6107-2018] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) version 4.10 (V4) level 2 aerosol data products, released in November 2016, include substantial improvements to the aerosol subtyping and lidar ratio selection algorithms. These improvements are described along with resulting changes in aerosol optical depth (AOD). The most fundamental change in V4 level 2 aerosol products is a new algorithm to identify aerosol subtypes in the stratosphere. Four aerosol subtypes are introduced for the stratospheric aerosols: polar stratospheric aerosol (PSA), volcanic ash, sulfate/other, and smoke. The tropospheric aerosol subtyping algorithm was also improved by adding the following enhancements: (1) all aerosol subtypes are now allowed over polar regions, whereas the version 3 (V3) algorithm allowed only clean continental and polluted continental aerosols; (2) a new "dusty marine" aerosol subtype is introduced, representing mixtures of dust and marine aerosols near the ocean surface; and (3) the "polluted continental" and "smoke" subtypes have been renamed "polluted continental/smoke" and "elevated smoke", respectively. V4 also revises the lidar ratios for clean marine, dust, clean continental, and elevated smoke subtypes. As a consequence of the V4 updates, the mean 532 nm AOD retrieved by CALIOP has increased by 0.044 (0.036) or 52 % (40 %) for nighttime (daytime). Lidar ratio revisions are the most influential factor for AOD changes from V3 to V4, especially for cloud-free skies. Preliminary validation studies show that the AOD discrepancies between CALIOP and AERONET/MODIS (ocean) are reduced in V4 compared to V3.
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Affiliation(s)
- Man-Hae Kim
- NASA Postdoctoral Program (USRA), Hampton, VA, USA
| | - Ali H. Omar
- NASA Langley Research Center, Hampton, VA, USA
| | | | | | | | | | | | - Zhaoyan Liu
- Science Systems and Applications, Inc., Hampton, VA, USA
| | | | | | - Jayanta Kar
- Science Systems and Applications, Inc., Hampton, VA, USA
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Kim MH, Omar AH, Tackett JL, Vaughan MA, Winker DM, Trepte CR, Hu Y, Liu Z, Poole LR, Pitts MC, Kar J, Magill BE. The CALIPSO Version 4 Automated Aerosol Classification and Lidar Ratio Selection Algorithm. ATMOSPHERIC MEASUREMENT TECHNIQUES 2018; 11:6107-6135. [PMID: 31921372 DOI: 10.1175/2009jtecha1231.1] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) version 4.10 (V4) level 2 aerosol data products, released in November 2016, include substantial improvements to the aerosol subtyping and lidar ratio selection algorithms. These improvements are described along with resulting changes in aerosol optical depth (AOD). The most fundamental change in V4 level 2 aerosol products is a new algorithm to identify aerosol subtypes in the stratosphere. Four aerosol subtypes are introduced for the stratospheric aerosols: polar stratospheric aerosol (PSA), volcanic ash, sulfate/other, and smoke. The tropospheric aerosol subtyping algorithm was also improved by adding the following enhancements: (1) all aerosol subtypes are now allowed over polar regions, whereas the version 3 (V3) algorithm allowed only clean continental and polluted continental aerosols; (2) a new "dusty marine" aerosol subtype is introduced, representing mixtures of dust and marine aerosols near the ocean surface; and (3) the "polluted continental" and "smoke" subtypes have been renamed "polluted continental/smoke" and "elevated smoke", respectively. V4 also revises the lidar ratios for clean marine, dust, clean continental, and elevated smoke subtypes. As a consequence of the V4 updates, the mean 532 nm AOD retrieved by CALIOP has increased by 0.044 (0.036) or 52 % (40 %) for nighttime (daytime). Lidar ratio revisions are the most influential factor for AOD changes from V3 to V4, especially for cloud-free skies. Preliminary validation studies show that the AOD discrepancies between CALIOP and AERONET/MODIS (ocean) are reduced in V4 compared to V3.
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Affiliation(s)
- Man-Hae Kim
- NASA Postdoctoral Program (USRA), Hampton, VA, USA
| | - Ali H Omar
- NASA Langley Research Center, Hampton, VA, USA
| | | | | | | | | | | | - Zhaoyan Liu
- Science Systems and Applications, Inc., Hampton, VA, USA
| | - Lamont R Poole
- Science Systems and Applications, Inc., Hampton, VA, USA
| | | | - Jayanta Kar
- Science Systems and Applications, Inc., Hampton, VA, USA
| | - Brian E Magill
- Science Systems and Applications, Inc., Hampton, VA, USA
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