Deep Convective Cloud Top Altitudes at High Temporal and Spatial Resolution

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. Plain Language Summary Convection modifies the water vapor concentration and injects trace gases into the upper troposphere and the lower stratosphere. To quantify the impact of convection, we have developed a data set of convective cloud top altitudes. Our algorithm uses lidar and cloud radar data to calibrate a combination of rainfall and geostationary satellite brightness temperature data to produce a database of convective cloud top altitudes. The statistics of our high-resolution convective cloud top altitudes agree well with the statistics of other more limited convective cloud top data sets, especially over the oceans and in the tropics.