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.

ABSTRACT: 15 years of Aqua CERES and 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_d ). Absolute (Sa=?A?Nd) and relative (Sr=?A?ln(Nd)) albedo susceptibilities are computed seasonally by exploiting the linear relationship between A and ln(N_d ) for shallow liquid clouds. Subtropical stratiform clouds (eastern Pacific, eastern Atlantic, and Australia) yield the highest S_r , followed by the extratropical oceans during their hemispheric summer. When S_r is cast in terms of F, the eastern Pacific clouds dominate S_r , with a secondary maximum offshore eastern Asia. S_a is mainly governed by N_d , with more pristine environments being more susceptible to change their albedo. While both S_a and S_r are advantageous for understanding radiative aspects of the aerosol indirect effect, S_r is more suitable for calculating changes in A and F due to the linear relationship between A and ln(N_d ).

SUBMITTER: Painemal D 

PROVIDER: S-EPMC7787139 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature