The Hadley Centre Atmospheric General Circulation Model (HadAM2b): An evaluation of the Southern Hemisphere synoptic pattern simulation

An evaluation of the Hadley Centre atmospheric general circulation model, HadAM2b, is pre-sented, mainly focused on the ability of the model to simulate Southern Hemisphere (SH) storm tracks and the assessment of the effects of changing resolution. Standard resolution (2.5° latitude by 3.75° longitude) and high resolution (0.833° latitude by 1.25° longitude) AMIP (Atmospheric Model Intercomparison Project) runs, in which the models are forced with ob-served monthly varying sea surface temperature (SSTs), are compared with NCEP re-analyses data for the period 1982-1995.

We focus on the model’s simulation of selected variables representative of the mean state and eddy properties which characterize high frequency activity of the SH. Some relevant features of the mean climate simulated at the standard and high resolutions are compared with stan-dard climatology. Comparison of some transient diagnostics is also presented in this paper and a summary of the strengths and deficiencies of the simulations are discussed.