DOI: 10.1002/2014GL061896
论文题名: CALIPSO observations of near-cloud aerosol properties as a function of cloud fraction
作者: Yang W. ; Marshak A. ; Várnai T. ; Wood R.
刊名: Geophysical Research Letters
ISSN: 0094-9465
EISSN: 1944-9196
出版年: 2014
卷: 41, 期: 24 起始页码: 9150
结束页码: 9157
语种: 英语
英文关键词: aerosol
; CALIPSO
; cloud
; cloud fraction
; sampling
; transition zone
Scopus关键词: Backscattering
; Clouds
; Optical radar
; Sampling
; Statistics
; CALIPSO
; Cloud enhancements
; Cloud fraction
; Composite statistics
; Fraction variation
; Logarithmic functions
; Sampling artifacts
; Transition zones
; Aerosols
; aerosol property
; artifact
; backscatter
; CALIPSO
; lidar
; sampling
; statistical analysis
; transition zone
; Azores
; Portugal
英文摘要: This paper uses spaceborne lidar data to study how near-cloud aerosol statistics of attenuated backscatter depend on cloud fraction. The results for a large region around the Azores show that (1) far-from-cloud aerosol statistics are dominated by samples from scenes with lower cloud fractions, while near-cloud aerosol statistics are dominated by samples from scenes with higher cloud fractions; (2) near-cloud enhancements of attenuated backscatter occur for any cloud fraction but are most pronounced for higher cloud fractions; (3) the difference in the enhancements for different cloud fractions is most significant within 5 km from clouds; (4) near-cloud enhancements can be well approximated by logarithmic functions of cloud fraction and distance to clouds. These findings demonstrate that if variability in cloud fraction across the scenes used for composite aerosol statistics is not considered, a sampling artifact will affect these statistics calculated as a function of distance to clouds. For the Azores region data set examined here, this artifact occurs mostly within 5 km from clouds and exaggerates the near-cloud enhancements of lidar backscatter and color ratio by about 30%. This shows that for accurate characterization of the changes in aerosol properties with distance to clouds, it is important to account for the impact of changes in cloud fraction. Key Points Near-cloud aerosols around the Azores are studied using CALIPSO lidar dataData show that cloud fraction affects apparent aerosol enhancement near cloudsCloud fraction variations inflate near-cloud changes in composite statistics ©2014. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84921729534&doi=10.1002%2f2014GL061896&partnerID=40&md5=aa01e7eb0632cefa00f6868ab517d95f
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/6729
Appears in Collections: 气候减缓与适应
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作者单位: Goddard Earth Sciences Technology and Research, Universities Space Research Association, Columbia, MD, United States
Recommended Citation:
Yang W.,Marshak A.,Várnai T.,et al. CALIPSO observations of near-cloud aerosol properties as a function of cloud fraction[J]. Geophysical Research Letters,2014-01-01,41(24).