Global Estimates of Changes in Shortwave Low‐Cloud Albedo and Fluxes Due to Variations in Cloud Droplet Number Concentration Derived from CERES‐MODIS Satellite Sensors

Painemal, David [Point of Contact]

关键词: DROPS (LIQUIDS);    MODIS (RADIOMETRY);    SATELLITE OBSERVATION;    SOLAR RADIATION;    ALBEDO;    AEROSOLS;   

RP-ID  :  NF1676L-30145

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

Fifteen years of Aqua Clouds and the Earth's Radiant Energy Systems (CERES) and MOderate resolution Imaging Spectroradiometer (MODIS) observations are combined to derive nearly global maps of shortwave albedo (A) and flux (F) response to changes in cloud droplet number concentration (N(sub d)). Absolute (S(sub a) = ∂A/∂N(sub d)) and relative (S(sub r) = ∂A/∂In(N(sub d)) albedo susceptibilities are computed by exploiting the linear relationship between A and ln (N(sub d)) for shallow liquid clouds. Subtropical stratiform clouds over the eastern Pacific, eastern Atlantic, and off the coast of eastern Asia yield the highest S(sub r), followed by the extratropical oceans during their hemispheric summer. When S(sub r) is cast in terms of F, the eastern Pacific clouds dominate S(sub r). S(sub a) is mainly governed by N(sub d), with offshore clouds producing high S(sub a). While both S(sub a) and S(sub r) are advantageous for understanding radiative aspects of the aerosol indirect effect, S(sub r) is more suitable for calculating changes in A and F due to the linearity of the A‐ln (N(sub d)) relationship.