Evaluation of High-Resolution Regional Climate Model Performance over Surabaya Metropolitan Area Using RegCM5 MOLOCH Core

Abstract

As climate change continue to impact weather patterns globally, understanding regional effects has become more important. Traditional global climate model lacks the resolution to capture the dynamics of regional climate, leading to uncertainties in predicting local climate. There has been some research about high-resolution regional climate model, but not specific to Indonesia especially Surabaya. This paper aim is to evaluate the new MOLOCH non-hydrodynamical core of RegCM5 in producing high-resolution regional climate model. This study covers Surabaya Metropolitan Area, with a resolution of 5 km spanning 60 cells both on longitudinal and latitude. We compared 3 different scheme combinations, 2 of them based on previous research and one is a new combination. We utilized ERA5 0.25° surface and sea surface temperature datasets as global climate model. We found that the model had cold bias for maximum temperature and warm bias for minimum temperature. As for precipitation and surface upwelling longwave radiation the model performed a good result, it had a similar pattern with a small bias. Overall, the MOLOCH core performed a good result, but bias correction is needed for both maximum and minimum temperature. The findings might shed light to the future of regional climate modelling.