Assessment of GCM-based rainfall simulations for the Austral-Indonesian region

Abstract

[Summary]: Our assessment shows considerable discrepancies between observed and simulated rainfall amongst the 21 models. Generally, the representation of rainfall is better for northern Australia during seasonally dry periods (Austral winter and spring). More than half of the models reproduce unrealistic rainfall distributions, particularly due to overestimation of rainfall in the Indonesian region. The CADS shows that MIUB-ECHO-G model has the lowest eviation from recorded seasonal rainfall in summer and winter, while MRI-CGCM2.3.2a performs best during transition periods in autumn and spring. The late 21st century rainfall assessments of these two models indicate considerable rainfall changes particularly over Indonesia for all seasons. Rainfall projections for northern Australia, however, show little changes in rainfall patterns. Structural differences between these two models and other GCMs need to be investigated to pinpoint the physical causes of differences in performance.