Entrainment Rates Associated with Deep Convection Estimated by Aura and CloudSat Observations

Convective entrainment rates are often derived from in-situ measurements or cloud-resolving model simulations. Global distributions of entrainment rates are not yet available. This study attempts to estimate convective entrainment rates from satellite observations using Aura carbon monoxide (CO) measurements associated with deep convective cases identified by CloudSat data. CO is treated as a conserved quantity over convective transport time scales and a simple entraining-plume model is used to derive entrainment rates. The model assumes a constant entrainment rate and iteratively determines the entrainment rate for each deep convective case using Aura TES and MLS joint retrieval of CO profiles. We find that the average entrainment rates are roughly ~10%/km for deep convection but with large uncertainties associated with the Aura CO data quality. The geographic and seasonal variations of convective entrainment rates over the globe are examined. The results will serve as a reference to help improve parameterizations of convective entrainment in general circulation models.