Role of monsoon interannual variability on the climate model prediction of seasonal rainfall over Indonesia

Abstract

Hindcast produced by a model used in a numerical model-based seasonal prediction system is an essential part of the operational seasonal prediction system. This paper is aimed at evaluating the performance of POAMA and CFSv2 models in predicting the interannual variability of seasonal rainfall over Indonesia. The data used in this research are obtained from POAMA m24 model and CFSv2 model. A seasonal empirical orthogonal function analysis is used for examining the year-to-year variation of seasonal rainfall. The results reveal the influence of ENSO on seasonal rainfall over Indonesia. These results are well simulated by both models, although there is a decrease in the accuracy of the models for longer lead-time. The areal average may suggest that POAMA m24 model with a resolution of T24 has better accuracy for longer lead time, but CFSv2 with a resolution of T126 is superior in simulating the spatial pattern of rainfall over Indonesia.