Using Global and Regional Model Simulations to Understand Maritime Continent Wet-Season Rainfall Variability

Abstract

The Maritime Continent is a densely populated area of complex topography located between the Pacific and Indian Oceans. It is an area where model skill is particularly important but also difficult to obtain. In this study we examine interannual austral summer rainfall variability in the region and the teleconnection to the El Niño–Southern Oscillation (ENSO) in observation-based data, reanalyses, and global and regional atmosphere-only model simulations. We show that model ability to capture interannual rainfall variability is strongly related to model skill in reproducing the ENSO teleconnection to the region, despite strong spatial variability in the ENSO-rainfall response in coastal areas. Model ability in capturing the spatial pattern of both the midtropospheric moisture and circulation response to ENSO is a strong predictor for model performance in capturing the ENSO-Maritime Continent rainfall teleconnection. High-resolution regional simulations and better performing models have opposing ENSO-rainfall teleconnections between land and sea areas.