Climate Change Projection for the western North Pacific Ocean by Dynamical Downscaling

Abstract

Global climate models (GCMs) provide future climate projection on global scale. However, assessments of climate change (CC) impacts, adaptation to CC, and mitigation of CC require detailed regional-scale information which can be obtained by regional climate models (RCMs) mainly through their ability to accommodate much higher spatial resolution. This study aims to develop a RCM for the western North Pacific Ocean where considerable climate changes have been occurred, and to apply them to future climate change projection. The RCM consists of the Regional Ocean Modeling System (ROMS) as an oceanic component and the Weather Research Forecast (WRF) as an atmospheric component. The ocean model has horizontal resolution of 1/12 degrees, while the atmospheric model, covering the East Asia region, has horizontal resolution of 50km. As a first step for future climate projection with the RCM, we used future climate changes by CanESM2 that well reproduces the East Asian monsoon. Both ocean and atmospheric RCM projections with a pseudo global warming method show some prominent features including considerable surface warming in the East/Japan Sea, in the Yellow Sea, and Okhotsk Sea, an overall freshening concentrated near the Kuroshio-Oyashio, and an opposite trend in precipitation change between the southern and northern regions over the Korean Peninsula. Detailed regional patterns in future changes will be presented and compar regional climate models (RCMs) mainly through their ability to accommodate much higher spatial resolution. This study aims to develop a RCM for the western North Pacific Ocean where considerable climate changes have been occurred, and to apply them to future climate change projection. The RCM consists of the Regional Ocean Modeling System (ROMS) as an oceanic component and the Weather Research Forecast (WRF) as an atmospheric component. The ocean model has horizontal resolution of 1/12 degrees, while the atmospheric model, covering the East Asia region, has horizontal resolution of 50km. As a first step for future climate projection with the RCM, we used future climate changes by CanESM2 that well reproduces the East Asian monsoon. Both ocean and atmospheric RCM projections with a pseudo global warming method show some prominent features including considerable surface warming in the East/Japan Sea, in the Yellow Sea, and Okhotsk Sea, an overall freshening concentrated near the Kuroshio-Oyashio, and an opposite trend in precipitation change between the southern and northern regions over the Korean Peninsula. Detailed regional patterns in future changes will be presented and compar