Assessing Models' Realization of the Large-Scale Teleconnections Between Drought in Central-Southwest Asia and Tropical Sea Surface Temperatures

Observational analysis has shown a strong link between drought in Central-Southwest Asia and tropical sea surface temperatures (SSTs) via changes to tropical precipitation and an associated circulation response.  Here we analyze how well a range of current models, including those in the North American Multi-Model Ensemble, reproduce this link and the associated teleconnections.  We consider the models run in an AMIP context (specified SSTs), a seasonal forecasting context (coupled mode, but initial conditions still important), and a free-running context (coupled mode, where initial conditions have lost their influence).  We find a wide range in the ability of individual models to realistically capture the observed relationship and even important differences between the teleconnections realized in 1-2 month forecasts and in 6 month forecasts from the same model.  The results have important implications for seasonal forecasting, climate change projections, and model development.