Assessment of the RegCM4 over East Asia and future precipitation change adapted to the RCP scenarios

Abstract

In this study, we investigated spatial and temporal changes in precipitation over the Coordinated Regional Climate Downscaling Experiment (CORDEX) East Asia domain, for present (1986)(1987)(1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005) and future (2031-2050) periods using the Regional Climate Model version 4 (RegCM4). Future meteorology produced by the Hadley Center Global Environmental Model version 2 coupled with the Atmosphere-Ocean (HadGEM2-AO) following global climate change scenarios (Representative Concentration Pathways (RCP) 4.5 and 8.5) was used as meteorological boundary conditions for the RegCM4. Six subregions (South Korea, North China, South China, Japan, Mongolia, and India) in the CORDEX East Asia domain were considered for analysis. The RegCM4 simulated spatial distributions of precipitation over East Asia with a correlation coefficient of 0.7 against Climate Research Unit data. The simulation skills of its temporal variability varied based on geographical regions and seasons, showing relatively poorer performance (underestimation in rainfall amount) in summer than in winter, in general. The future climate simulations by the RegCM4 presented that the East Asian continental regions will be warmer and more humid, leading to increased precipitation amounts, especially in the summer. The summer precipitation amount was projected to increase by about 5%, on average, over the East Asian domain, 5À15% in most subregions, and even higher (44% and 24%) in the South Korean region for the RCP 4.5 and 8.5 scenarios, respectively. It was also expected that heavy rainfall (> 50 mm/d) events may occur more frequently in the future possibly owing to meteorological changes that are favorable to convective heavy precipitation.

Multi-year downscaling application of two-way coupled WRF v3.4 and CMAQ v5.0.2 over east Asia for regional climate and air quality modeling: model evaluation and aerosol direct effects

“…As a result of these deficiencies, the dynamical downscaling technique has been widely used in regional climate studies (Oh et al, 2014;Wang and Kotamarthi, 2015;Xu and Yang, 2015). Dynamical downscaling uses initial conditions (ICs) and boundary conditions (BCs) from global models to drive regional models for high-resolution simulations.…”

Regional climate projection over South Korea simulated by the HadGEM2-AO and WRF model chain under RCP emission scenarios

“…In particular, numerous modeling studies have confirmed that RCMs with relatively high resolution simulate climatic characteristics more skillfully than do GCMs over East Asia (e.g. Gao et al 2001, Im et al 2007, Yu et al 2010, Zou & Zhou 2013, Oh et al 2014). Based on a series of simulations, Gao et al (2006) highlight the role of adequate spatial resolution to resolve the physical and dynamical process in simulating the climate over East Asia.…”

Simulating the Impacts of Tree, C3, and C4 Plant Functional Types on the Future Climate of West Africa

“…These changes may be associated with the differences in the identified biases from the two dynamic vegetation simulations. PRESd2 introduced the highest magnitude of cold biases among the three historical climate simulations over most parts of West Africa, but PRES and PRESd1 underestimated temperature along the coast, orographic region, and north of 18° N. with [39,[65][66][67]. RegCM4 The model reproduced reasonably well the amplitude of the seasonal variations of temperature and precipitation over West Africa in all seasons with a strong correlation, which ranged from 0.5 to 0.9 (Figures 8 and 9).…”

“…Previous regional climate model simulations over West Africa reported similar biases [18,30,[60][61][62][63][64]. The model biases were associated with different factors, such as the absence of sufficient observing stations in the mountainous region, the influence of land/sea boundary conditions, physics configuration of the model, inherited biases from the driving global circulation models (GCMs), or the choice of cumulus convective parameterization [39,[65][66][67].…”

“…RegCM4.4 has demonstrated robust capability in the simulation of the mean climate over different regions [37][38][39][40], and is therefore useful for climate projections and paleoclimate studies. The model has 18 vertical sigma levels extending from the surface to 50 hPa level, and provides different options for cumulus convection parameterizations and land surface schemes.…”