New Global View of Above-Cloud Absorbing Aerosol Distribution Based on CALIPSO Measurements
Above-low-level-cloud aerosols (ACAs) have gradually gained more interest in recent years; however, the combined aerosol−cloud radiation effects are not well understood. The uncertainty about the radiative effects of aerosols above cloud mainly stems from the lack of comprehensive and accu...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-10-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/11/20/2396 |
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| author | Wenzhong Zhang Shumei Deng Tao Luo Yang Wu Nana Liu Xuebin Li Yinbo Huang Wenyue Zhu |
| author_facet | Wenzhong Zhang Shumei Deng Tao Luo Yang Wu Nana Liu Xuebin Li Yinbo Huang Wenyue Zhu |
| author_sort | Wenzhong Zhang |
| collection | DOAJ |
| description | Above-low-level-cloud aerosols (ACAs) have gradually gained more interest in recent years; however, the combined aerosol−cloud radiation effects are not well understood. The uncertainty about the radiative effects of aerosols above cloud mainly stems from the lack of comprehensive and accurate retrieval of aerosols and clouds for ACA scenes. In this study, an improved ACA identification and retrieval methodology was developed to provide a new global view of the ACA distribution by combining three-channel CALIOP (The Cloud−Aerosol Lidar with Orthogonal Polarization) observations. The new method can reliably identify and retrieve both thin and dense ACA layers, providing consistent results between the day- and night-time retrieval of ACAs. Then, new four-year (2007 to 2010) global ACA datasets were built, and new seasonal mean views of global ACA occurrence, optical depth, and geometrical thickness were presented and analyzed. Further discussion on the relative position of ACAs to low clouds showed that the mean distance between the ACA layer and the low cloud deck over the tropical Atlantic region is less than 0.2 km. This indicates that the ACAs over this region are more likely to be mixed with low-level clouds, thereby possibly influencing the cloud microphysics over this region, contrary to findings reported from previous studies. The results not only help us better understand global aerosol transportation and aerosol−cloud interactions but also provide useful information for model evaluation and improvements. |
| first_indexed | 2024-12-24T03:31:26Z |
| format | Article |
| id | doaj.art-9ea8921b31f643fcb32a6e6fa680d9b8 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-12-24T03:31:26Z |
| publishDate | 2019-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-9ea8921b31f643fcb32a6e6fa680d9b82022-12-21T17:17:11ZengMDPI AGRemote Sensing2072-42922019-10-011120239610.3390/rs11202396rs11202396New Global View of Above-Cloud Absorbing Aerosol Distribution Based on CALIPSO MeasurementsWenzhong Zhang0Shumei Deng1Tao Luo2Yang Wu3Nana Liu4Xuebin Li5Yinbo Huang6Wenyue Zhu7Key Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, ChinaSchool of Environment and Energy Engineering, Anhui Jianzhu University, Hefei 230031, ChinaKey Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, ChinaKey Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, ChinaKey Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, ChinaKey Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, ChinaKey Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, ChinaKey Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, ChinaAbove-low-level-cloud aerosols (ACAs) have gradually gained more interest in recent years; however, the combined aerosol−cloud radiation effects are not well understood. The uncertainty about the radiative effects of aerosols above cloud mainly stems from the lack of comprehensive and accurate retrieval of aerosols and clouds for ACA scenes. In this study, an improved ACA identification and retrieval methodology was developed to provide a new global view of the ACA distribution by combining three-channel CALIOP (The Cloud−Aerosol Lidar with Orthogonal Polarization) observations. The new method can reliably identify and retrieve both thin and dense ACA layers, providing consistent results between the day- and night-time retrieval of ACAs. Then, new four-year (2007 to 2010) global ACA datasets were built, and new seasonal mean views of global ACA occurrence, optical depth, and geometrical thickness were presented and analyzed. Further discussion on the relative position of ACAs to low clouds showed that the mean distance between the ACA layer and the low cloud deck over the tropical Atlantic region is less than 0.2 km. This indicates that the ACAs over this region are more likely to be mixed with low-level clouds, thereby possibly influencing the cloud microphysics over this region, contrary to findings reported from previous studies. The results not only help us better understand global aerosol transportation and aerosol−cloud interactions but also provide useful information for model evaluation and improvements.https://www.mdpi.com/2072-4292/11/20/2396above-cloud aerosollow-level cloudcalipso |
| spellingShingle | Wenzhong Zhang Shumei Deng Tao Luo Yang Wu Nana Liu Xuebin Li Yinbo Huang Wenyue Zhu New Global View of Above-Cloud Absorbing Aerosol Distribution Based on CALIPSO Measurements Remote Sensing above-cloud aerosol low-level cloud calipso |
| title | New Global View of Above-Cloud Absorbing Aerosol Distribution Based on CALIPSO Measurements |
| title_full | New Global View of Above-Cloud Absorbing Aerosol Distribution Based on CALIPSO Measurements |
| title_fullStr | New Global View of Above-Cloud Absorbing Aerosol Distribution Based on CALIPSO Measurements |
| title_full_unstemmed | New Global View of Above-Cloud Absorbing Aerosol Distribution Based on CALIPSO Measurements |
| title_short | New Global View of Above-Cloud Absorbing Aerosol Distribution Based on CALIPSO Measurements |
| title_sort | new global view of above cloud absorbing aerosol distribution based on calipso measurements |
| topic | above-cloud aerosol low-level cloud calipso |
| url | https://www.mdpi.com/2072-4292/11/20/2396 |
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