The layer-mean radar reflectivity Z 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 e and Re for warm clouds. Global statistics for seasonally averaged data reveals that radar reflectivities Z 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 e < -10 dBZ. For Z e > -10 dBZ, Z e depends on Re 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.