Hogan, T.F., 1995: Identifying sensitivities in GCM's parameterizations using the Koeppen climate classification (NRL). Abstracts of the First International AMIP Scientific Conference, Monterey, California, 97.

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Identifying the differences between the observed and modeled Koeppen climate classification is an excellent tool in determining both the systematic errors in general circulations models' rainfall patterns and the improvements due to changes in physical parameterizations. Several 10 year integrations have been performed and the Koeppen climates computed with the Navy Operational Global Atmospheric Prediction System (NOGAPS) with different planetary boundary layer, surface parameterizations and upper air vertical diffusion schemes. When compared with the Louis scheme, the Troen and Mahrt planetary boundary layer formulation substantially reduces the ocean regions where the rainfall is deficient and slightly improves the land precipitation. Inclusion of an advanced surface vegetation atmospheric transfer scheme further improves the overall climate of NOGAPS. However, multi-year runs with different formulations of mixing above the planetary layer height also show large differences in the rainfall distribution. It is believed a better understanding and modeling of the momentum and heat mixing above the PBL is needed in the models before truly accurate climate modeling is to be achieved.