Linear response functions of two convective parameterization schemes

Abstract

[1] Two 1-D atmospheric column models containing convective parameterization schemes are compared to a 3-D cloud system resolving model (CSRM) using a recent technique that admits study of responses of convection to small temperature and moisture anomalies. The MIT Single-Column Model (MSCM) and Diabat3 (D3) are the column models of study. There exist notable differences between the responses of the column models and those of the CSRM. Both column models retain prescribed temperature anomalies and MSCM retains moisture anomalies for much longer than the CSRM. D3 excessively warms anomalous moist layers. Neither column model warms the upper troposphere following moist anomalies or cools the upper troposphere following warm anomalies in the middle troposphere. Responses in both column models are mostly local—suggesting that a significant attribute of the CSRM response is missing from these models. Such differences have implications to the simulation of large-scale convective phenomena, such as the growth and propagation of convectively coupled waves (CCW). The technique employed herein can be used as a basis for tuning and modifying convective parameterization schemes.