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Influence of aerosols on the shortwave cloud radiative forcing from North Pacific oceanic clouds: Results from the Cloud Indirect Forcing Experiment (CIFEX)
Author(s) -
Wilcox Eric M.,
Roberts Greg,
Ramanathan V.
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl027150
Subject(s) - environmental science , cloud forcing , atmospheric sciences , cloud top , shortwave , effective radius , overcast , radiative forcing , forcing (mathematics) , marine stratocumulus , drop (telecommunication) , liquid water content , liquid water path , radiative transfer , cloud height , satellite , cloud albedo , aerosol , meteorology , cloud computing , cloud cover , geology , physics , telecommunications , quantum mechanics , astronomy , sky , galaxy , computer science , operating system
Aerosols over the Northeastern Pacific Ocean enhance the cloud drop number concentration and reduce the drop size for marine stratocumulus and cumulus clouds. These microphysical effects result in brighter clouds, as evidenced by a combination of aircraft and satellite observations. In‐situ measurements from the Cloud Indirect Forcing Experiment (CIFEX) indicate that the mean cloud drop number concentration in low clouds over the polluted marine boundary layer is greater by 53 cm −3 compared to clean clouds, and the mean cloud drop effective radius is smaller by 4 μ m. We link these in‐situ measurements of cloud modification by aerosols, for the first time, with collocated satellite broadband radiative flux observations from the Clouds and the Earth's Radiant Energy System to show that these microphysical effects of aerosols enhance the top‐of‐atmosphere cooling by −9.9 ± 4.3 W m −2 for overcast conditions.