Estimating Convective Entrainment Rates Associated with Deep Convection Using Aura CO, CALIPSO/CloudSat, and AIRS Observations and Comparison with GEOS-5 Simulations

Entrainment rates (ER) in convective parameterizations remain as sensitive parameters with much uncertainty in model simulations. This study attempts to estimate convective entrainment rates from satellite observations using Aura TES and MLS carbon monoxide (CO) measurements associated with deep convective cases as identified by CloudSat/CALIPSO data. CO is treated as a conserved quantity over convective transport time scales and a simple entraining-plume model is used to derive ER. The model currently 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. The relationships of the observational estimates of ER with convective height, environmental relative humidity, and convective available potential energy derived from AIRS data are compared with those from GEOS-5 simulations. The results of this study will serve as a reference to help improve parameterizations of convective entrainment in general circulation models.