Radiation characteristics of low and high clouds in different oceanic regions observed by CERES and MODIS

Abstract

Radiative properties measured by the Clouds and the Earth's Radiant Energy System (CERES) and the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua spacecraft are evaluated for the same types of clouds in selected areas. Individual measurements are analysed statistically to take advantage of both gridded and individual cloud characteristics. The seasonal variations of radiative fluxes for the same types of clouds from different areas are remarkably similar. Although cloud liquid water paths (LWPs) or ice water paths (IWPs) vary considerably for the same types of clouds, their statistical distributions are very stable for different periods and areas, suggesting that the regional differences in dynamics and thermodynamics primarily cause changes in the cloud frequency or coverage and only secondarily in the cloud macrophysical characteristics such as IWPs or LWPs. These results establish a systematic approach of observations for testing modelled cloud statistics and for improving cloud model parameterizations.

Acknowledgements

We thank B. Wielicki, G. Gibson, K.-M. Xu, D. Young and D. Garber for their invaluable comments and suggestions. This research was supported by NASA's CERES mission and the NASA Energy and Water cycle Studies (NEWS) program. The CERES products were obtained from the NASA Langley Atmospheric Sciences Data Center in Hampton, Virginia.