Projection of late 21st century (2071–2100) fine-scale climate changes over the Korean Peninsula using RegCM4 based on four RCP scenarios

English Abstract:

In this study, we projected late 21st century (2071–2100) fine-scale climate changes over the Korean Peninsula using RegCM4 based on the four Representative Concentration Pathway (RCP) scenarios (2.6, 4.5, 6.0, and 8.5). HadGEM2-AO data provided by the National Institute of Meteorological Research was used as the lateral boundary conditions for RegCM4 with a horizontal resolution of 12.5 km. The simulation skills of RegCM4 for the spatio-temporal variations of current climate (1981-2010) over Northeast Asia are evaluated using CRU data. The annual mean temperature over South Korea in the late 21st century is expected to increase by about +1.62ᵒC, +2.71ᵒC, +2.76ᵒC, and +4.53ᵒC, respectively, compared with the present climate under the RCP scenarios. Annual precipitation is projected to increase by about +0.24 mm/day and +0.40 mm/day under the RCP2.6 and RCP8.5 scenarios, respectively. Interannual variability (IAV) of temperature is projected to increase and decrease significantly under RCP6.0 and RCP8.5 and RCP2.6 and RCP4.5, respectively. The significant increase in IAV of temperature under RCP6.0 and RCP8.5 indicates the possibility that abnormal temperatures may be increased in the late 21st century. Additionally, the IAV of summer precipitation is also projected to clearly increaseunder RCP6.0. The portion of heavy rainfalls (> 50 mm/day) is also expected to increase irrespective of scenarios, which indicates the possibility that extreme droughts and heavy rainfalls may be increased.This is considered to be related to the fact that destabilized atmospheric environmentsby the combined effects of increased temperature and mixing ratio at the lower troposphere and the increased cold advection at the upper troposphere.