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 = /) and relative (Sr = /) 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) ).