Evaluation and Investigation of E3SMv1 Simulations of Clouds and Radiation Over the Southern Polar Region
This work is part of the systematic evaluation of E3SMv1 simulations over the southern polar region to provide an assessment of the simulated atmospheric forcings that exert a strong influence on the cryosphere system around the Antarctica. The atmosphere model simulations used are part of the E3SMv1 DECK (Diagnostic, Evaluation and Characterization of Klima) experiments, with prescribed observational sea surface temperature and ice coverage. Preliminary analysis shows that the simulated cloud, precipitation, and radiation fields, in comparison with limited available observations, exhibits large discrepancies that are with strong seasonality and sharp contrast over ice sheets, on the periphery of the ice sheets and over the circumpolar southern oceans. These are clear indications that issues in cloud physics, surface-air interactions and the ability to reproduce synoptic scale weather systems over the region may all have a large influence on the model results. Statistics of cloud and radiation measurements from the AWARE (ARM West Antarctic Radiation Experiment) campaign will provide an additional reference to aid the evaluation, while cases representative of the polar environment and the associated model characteristics will be used to investigate the processes contributing to the model behavior. Case studies over the AWARE campaign sites will be used to investigate the simulated cloud processes with single column version of the E3SMv1 atmosphere model. Meanwhile, CAPT (Cloud Associated Parameterizations Testbed)-based hindcasts with the full atmosphere model will also be used to examine the model skill in reproducing synoptic weather systems and the impact of synoptic-scale environment in conjunction with the model physical processes. The outcome of this work will be used to guide the improvement of the simulations of the atmospheric forcings important to modeling the cryosphere system.