DOI: 10.1002/2016JD026141
论文题名: The global aerosol-cloud first indirect effect estimated using MODIS, MERRA, and AeroCom
作者: McCoy D.T. ; Bender F.A.-M. ; Mohrmann J.K.C. ; Hartmann D.L. ; Wood R. ; Grosvenor D.P.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2017
卷: 122, 期: 3 起始页码: 1779
结束页码: 1796
语种: 英语
英文关键词: aerosol
; climate
; cloud
; microphysics
Scopus关键词: aerosol
; albedo
; climate forcing
; cloud cover
; cloud droplet
; cloud microphysics
; cloud water
; estimation method
; global climate
; MODIS
; power law
; radiative forcing
; stratocumulus
; Southern Ocean
英文摘要: Aerosol-cloud interactions (ACI) represent a significant source of forcing uncertainty in global climate models (GCMs). Estimates of radiative forcing due to ACI in Fifth Assessment Report range from −0.5 to −2.5 W m−2. A portion of this uncertainty is related to the first indirect, or Twomey, effect whereby aerosols act as nuclei for cloud droplets to condense upon. At constant liquid water content this increases the number of cloud droplets (Nd) and thus increases the cloud albedo. In this study we use remote-sensing estimates of Nd within stratocumulus regions in combination with state-of-the-art aerosol reanalysis from Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA2) to diagnose how aerosols affect Nd. As in previous studies, Nd is related to sulfate mass through a power law relationship. The slope of the log-log relationship between Nd and SO4 in maritime stratocumulus is found to be 0.31, which is similar to the range of 0.2–0.8 from previous in situ studies and remote-sensing studies in the pristine Southern Ocean. Using preindustrial emissions models, the change in Nd between preindustrial and present day is estimated. Nd is inferred to have more than tripled in some regions. Cloud properties from Moderate Resolution Imaging Spectroradiometer (MODIS) are used to estimate the radiative forcing due to this change in Nd. The Twomey effect operating in isolation is estimated to create a radiative forcing of −0.97 ± 0.23 W m−2 relative to the preindustrial era. ©2017. American Geophysical Union. All Rights Reserved. 资助项目: NNX14AG26G
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62715
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Department of Atmospheric Sciences, University of Washington, Seattle, United States; School of Earth and Environment, University of Leeds, Leeds, United Kingdom; Department of Meteorology and Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
Recommended Citation:
McCoy D.T.,Bender F.A.-M.,Mohrmann J.K.C.,et al. The global aerosol-cloud first indirect effect estimated using MODIS, MERRA, and AeroCom[J]. Journal of Geophysical Research: Atmospheres,2017-01-01,122(3)