Future change of thermal environment in a megacity projected by the regional climate model (RegCM4) and the vegetated urban canopy model (VUCM)

A dynamic downscaling approach using a regional climate model has been popularly used to simulate current and future climate in order to overcome drawbacks relevant to low spatial and temporal resolution of global climate models. we investigated changes in near surface temperature in an East Asian megacity of the coordinated regional climate downscaling experiment (CORDEX) domain for present (1986–2005) and future (2031–2050) periods using the Regional Climate Model version 4 (RegCM4) and the vegetated urban canopy model (VUCM). The regional climatic simulations were done with a grid spacing of 50 km and forced by two different global meteorological conditions that were produced by the Atmosphere–Ocean coupled Hadley Center Global Environmental Model version 2 (HadGEM2-AO) representing the representative concentration pathways (RCP) 4.5 and 8.5 scenarios. In order to better represent the urban area and associated physical processes, the VUCM was applied as a stand-alone mode using meteorological forcing of the RegCM4's climatic simulations. Both the model's ability in simulating near surface temperature was evaluated against surface meteorological observation from an urban site in the megacity. We will discuss projected climatic changes of thermal environment adapted to the RCP scenarios in an East Asian megacity and the capability of the urban canopy model for use in climatic simulation.