Global identification of warm cloud microphysical processes with combined use of A-Train observations

The layer-mean radar reflectivity (Z) over bar (e) observed by CloudSat and the columnar effective particle radius Re obtained from a combined microwave-shortwave analysis are combined to investigate the joint relationships between (Z) over bar (e) and (R) over bar (e) for warm clouds. Global statistics for seasonally averaged data reveals that radar reflectivities (Z) over bar (e) less than about -10 dBZ tend to relate to the effective radius via a sixth-power dependency, corresponding to a constant number concentration implying that the condensation particle growth process mainly takes place within the cloud layer for (Z) over bar (e) < -10 dBZ. For <(Z)over bar>(e) > -10 dBZ, (Z) over bar (e) depends on R-e through a cubic relation, corresponding to a constant mass concentration implying coagulation as the dominant particle growth process. These microphysical regimes so identified are shown to be consistent with CloudSat-inferred rainfall rate.