Regional Climate Simulation for Korea using Dynamic Downscaling and Statistical Adjustment

Abstract

Recently the regional impact assessment due to global warming is one of the urgent tasks to every country in the world, under the circumstances of increasing carbon dioxide in the atmosphere. This assessment must include not only meteorological factors, such as surface air temperature and precipitation, etc., but also the response of the local ecosystem. Based on a previous study, for example, it has been known that Phyllostachys' habitation, which is one of the bamboo species popular in Korea, is quite sensitive to temperature change, in particular during the winter season. Thus, adequate climate information is essential to derive a solid conclusion on the regional impact assessment for future climate change.In this study, we adopted a dynamical downscaling technique to get regional future climate information, with the regional climate model (MM5, Pennsylvania State University/National Center for Atmospheric Research mesoscale model) from the Max-Planck Institute for Meteorology Models and Data Group's Atmosphere-Ocean General Circulation Model (AOGCM) ECAHM4, and HOPE-G (ECHO-G) simulation for future climate, based on future greenhouse gas (GHG) emission scenario of the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios (SRES) A2. Through this nesting process we got reasonable regional climate change information. However, we found a couple of systematic differences, such as a cold bias in the surface air temperature, simulated by MM5 compared to that by the AOGCM ECHO-G. This cold bias may cause to loose credibility on the future climate scenario to the impact assessment studies. Accordingly, we introduced a transfer function to correct the systematic bias of the dynamic model in the regional-scale, and to predict the regional cliCorresponding author: Jai-Ho Oh, Integrated Climate System Modeling Group, Department of Environmental Atmospheric Sciences, Pukyong National University, 599-1 Daeyeon3-dong, Namgu, Busan 608-737, South Korea. E-mail: jhoh@pknu.ac.kr ( 2004, Meteorological Society of Japan mate from large-scale predictors. These transfer functions are obtained from the daily mean temperature of 17 surface observation stations in Korea for 10 years from 1992 to 2001, and 10-year simulation data obtained from regional climate model (RCM) for each mode of EOFA to correct the systematic bias of RCM data.With these transfer functions, we can correct the RMS error of the daily mean temperature in RCM as much as 47.6% in winter and 86.5% in summer. After dynamical downscaling and statistical adjustment, we may provide adequate climate change information for regional assessment studies.

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

“…The horizontal resolution of HOPE-G corresponds to a Gaussian T42 grid (@2.8 ) and the model employs 20 vertical levels (Min et al 2005). Analysis of results using the ECHO-G scenario (Oh et al 2004) showed that the A2 [B2] scenarios over East Asia (defined as grid box of 80 E-180 E, and 20 N-60 N) by 2100 result in an increase in temperature of 6.5 [4.5] K and an increase in precipitation of 10.5 [6.0]%, respectively.…”

“…The climate of Korea also has experienced a gradual warming (Oh et al 2004), as indicated by a significant warming trend from the observed record. In South Korea, the increasing rate of the average temperature is reported to be about 1.5 K during the 20th century mainly due to the greenhouse effect and rapid urbanization (Kwon 2005), which is almost three times of global warming trend.…”

“…In South Korea, the increasing rate of the average temperature is reported to be about 1.5 K during the 20th century mainly due to the greenhouse effect and rapid urbanization (Kwon 2005), which is almost three times of global warming trend. This indicates that Korea will be strongly expected to be vulnerable to climate change (Oh et al 2004;Boo et al 2006). In fact, there is discernable evidence that recent climate changes over Korea have already affected many environmental and biological systems (Boo et al 2004;Im et al 2007a).…”

“…In order to derive a meaningful interpretation about climate change and to project the potential future change, scenario simulations have been performed in numerous climate change studies (Gao et al 2001;Gallardo et al 2001;Giorgi et al 2004a,b;Mearns et al 1999;Oh et al 2004;Rä isä nen et al 2004;Kitoh et al 2005; Kusunoki et al 2006). Projections carried out based on future emission scenarios of greenhouse gases could provide useful insights for possible consequences due to climate change (Boo et al 2004).…”

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.…”