A29. Metrics for evaluation of E3SM atmospheric simulations over the Antarctica and Southern Ocean

Title

Metrics for evaluation of E3SM atmospheric simulations over the Antarctica and Southern Ocean

Authors

Wuyin Lin, Shaocheng Xie, Qi Tang, Yuying Zhang, Xianglei Huang

Abstract

This work establishes metrics for comprehensive assessment of the E3SM atmospheric simulations over the Southern Oceans and Antarctica. Large changes in atmospheric conditions over Antarctica and the surrounding oceans could have tremendous impact on the cryosphere system and the cascading effect on the Earth’s climate system could have important implications for the societies. Surface conditions exert direct influence on the cryosphere system as atmospheric forcing. Upper air conditions serve to portray the overall climate in the region  Model performance in simulating the surface and upper air conditions must be evaluated and well understood in order to be used for climate changes due to anthropogenic activities. Key metrics need to be established to facilitate such evaluation and track the progress of the model development in simulating the climate over this region. Southern Hemisphere can potentially have a tremendous impact on the environment and society globally. Global climate system in turn can exert influences on the cryosphere system around the Antarctica partly via the atmospheric forcing. The metrics for evaluating the linkage between polar climate and large-scale systems in lower latitudes will also be included. The atmosphere model simulations used here 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. The outcome of this work will be used to guide the improvement of the simulations of the atmospheric forcing important to modeling the cryosphere system.