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Impact of gas absorption and surface albedo on cloud radiative smoothing
Author(s) -
Schroeder Marc,
Bennartz Ralf
Publication year - 2003
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 - 10.1029/2002gl016523
Subject(s) - radiative transfer , radiance , smoothing , albedo (alchemy) , cloud albedo , environmental science , atmospheric radiative transfer codes , absorption (acoustics) , nadir , cloud top , atmospheric sciences , remote sensing , physics , meteorology , cloud computing , cloud cover , geology , optics , satellite , mathematics , art , statistics , operating system , astronomy , performance art , computer science , art history
Using visible and near infrared aircraft observations of stratocumulus clouds over land, the impact of gas absorption and surface albedo on cloud radiative smoothing has been studied. Time series of the observed nadir radiances have been converted into Fourier space, and the scale break as well as the large scale and small scale slopes of the resulting spatial power spectrum have been analyzed. An increase in gas absorption leads to a reduction in radiative smoothing due to a decreased likelihood of horizontal photon transport within the cloud. This can be seen both in the derived scale breaks and in the slope of the power spectrum at high spatial wavenumbers which exhibit a high correlation with cloud single scatter albedo. An increase in surface albedo leads to a radiative smoothing of the observed radiance field at scales proportional to the cloud height and to a decrease in the slope of the large scale spatial power spectrum.