Projected Change in Mean and Extreme Climate over Korea from a Double-Nested Regional Climate Model Simulation

Abstract

We present an analysis of a simulated climate projection covering the period 1971-2080 over the Korean Peninsula with a regional climate model (RegCM3) using a one-way double-nested system. The mother and nested domain cover the East Asian region at 60 km grid spacing and the Korean Peninsula at 20 km grid spacing, respectively. The mean climate state as well as the frequency and intensity of daily extreme events are investigated at various temporal and spatial scales, with a focus on surface air temperature and precipitation. Our analysis is primarily centered on the comparison of two 30-year climate periods between 2021-2050 and 2051-2080, in order to assess climatic changes at different time periods in response to anthropogenic forcings under the IPCC B2 emission scenario.Regarding the interdecadal variation of projected temperature and precipitation over the whole integration period, we find that the temperature change gradually increases by 3.2 K for the 2070s, with a persistently increasing trend. The projected precipitation in the future shows generally greater amounts than in the reference run despite significant interdecadal variation. A substantial increase (decrease) of hot (frost) spells is projected along with increasing of maximum and minimum temperature. Wet spells of long periods tend to be more frequent, accompanying the increase of precipitation amounts. The temperature changes are statistically significant at the 90% confidence level in all seasons and regions, indicating robustness of the projected change while the precipitation changes show low statistical confidence, especially summer season, due to the large natural variability. Based on the spatial distribution, although the general pattern between the mother and nested domain simulations shows similarity, more detailed structure over Korea is found in the nested domain simulation. By comparison of the change between 2021-2050 and 2051-2080 periods, the climate change signal of both temperature and precipitation becomes more pronounced in the late 21 st century as the greenhouse gas concentration is increased.

On the Elevation Dependency of Present-day Climate and Future Change over Korea from a High Resolution Regional Climate Simulation

“…6), and the results are averaged over all grid points in each elevation category. As expected, all temperature fields show considerable warming (more than 2.5 K) in response to emission forcing (A1B), which is in line with previous climate change studies over Korea (Im et al 2007a(Im et al , 2009Im and Kwon 2007). Interesting point is that this warming is quite inhomogeneous in various respects.…”

“…The mean, maximum, and minimum temperatures and precipitation from the inner nested domain of 20 km grid spacing (248 grid points) are compared to corresponding values from the 57 ASOS 30-year (1974-2005) data, as well as the 352 ASOS+AWS 10-year (1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006) data. The relatively high model resolution justifies the comparison between station data and grid point model data (Im et al 2007a). Note that, since the climatology of the recent 10 years (352 ASOS+AWS) could be different from that of the 30-year (57 ASOS) climatology, this comparison is not intended to provide quantitatively accurate validation.…”

Hydroclimatological response to dynamically downscaled climate change simulations for Korean basins

“…Recent studies have indicated that the Korean Peninsula appears to be particularly responsive to possible anthropogenic climatic changes (Boo et al 2004;Chung et al 2004;Im et al 2007b). The average temperature over South Korea has increased by approximately 1.5 • C during the twentieth century (Kwon 2005), which is more than twice the corresponding global warming reported by the Intergovernmental Panel on Climate Change (IPCC 2007).…”

“…In particular, Korean water resources are vulnerable to climate change because Korea is small, it has complicated mountainous terrain, and the climate of Korea is characterized by the occurrence of extreme precipitation episodes in the summer monsoon season (Chang et al , 2009Im et al 2007a). As support for this, Im et al (2007bIm et al ( , 2008a have reported a significant change in the projected future climate of Korea using a high resolution regional climate change simulation. The regional distribution of heavy precipitation (over 80 mm/day) changes considerably under enhanced greenhouse conditions, indicating changes in the flood vulnerable regions (Im et al 2008a).…”

Projecting Future Paddy Irrigation Demands in Korea Using High-resolution Climate Simulations

“…In Korea, concerning climate change modeling, several studies have been done using the MM5 and RegCM3 regional models along with ECHO-G GCM model outputs for Special Report on Emission Scenarios (SRES) A2 scenario (e.g., METRI, 2004;Oh et al, 2004;Im et al, 2007). Chang et al (2007) studied the vulnerability of Korean water resources to climate change and Bae et al (2008) studied potential changes in Korean water resources.…”