Deep Convective Cloud Top Altitudes at High Temporal and Spatial Resolution

Abstract

We describe and validate a method of calculating convective cloud top altitudes and potential temperatures up to 50° latitude at high spatial (0.25°) and temporal (3 hr) resolution. The approach uses the statistics of the CloudSat cloud radar deep convective cloud classification product coupled with nighttime CALIOP lidar measurements to effectively “calibrate” the high frequency, high resolution global rainfall and brightness temperature data that is used to derive convective cloud top altitudes. Thus, our product agrees well with the statistics of the CloudSat/CALIOP convective cloud tops, especially in the tropics and over oceanic regions. Agreement is reasonable, but not as good, for land-based convection. The estimated uncertainty in cloud top altitudes in our product is 0.5–1.0 km over land areas, with smaller uncertainties over the oceans. The diurnal cycle of the new convection data set is in good agreement with precipitation radar convective climatology.