Response of a GCM with a Hybrid Convection Scheme to a Tropical Pacific Sea Surface Temperature Anomaly

Abstract

Abstract A tropical Pacific sea surface temperature (SST) anomaly is included in a global general circulation model with a hybrid convection scheme. Results are compared with a similar version of the same model that includes a simple moist convective adjustment scheme and with observed data analyses from the European Centre for Medium-Range Weather Forecasts. The model with the hybrid scheme transports proportionately more heat and moisture higher into the troposphere in the vicinity of the SST anomaly, and the extratropical sensitivity to the SST anomaly is greater (larger-amplitude anomalies). Improvements in the simulated mean climate with the hybrid scheme result in an altered and more realistic extratropical response to the tropical SST anomaly. This is especially true for the Southern Hemisphere where the improvements to the mean climate simulation are most dramatic. This result is consistent with linear models that show a great dependence on the mean extratropical climate simulation for the type of...