Climate Change Research ›› 2021, Vol. 17 ›› Issue (4): 420-429.doi: 10.12006/j.issn.1673-1719.2020.197

• Changes in Climate System • Previous Articles     Next Articles

Evaluation of RegCM4 downscaling simulations on regional rainstorm events in China

CAI Yi-Heng1,2(), HAN Zhen-Yu3, ZHOU Bo-Tao1,2()   

  1. 1 School of Atmospheric Sciences, Nanjing University of Information Science and Technology, Nanjing 210044, China
    2 Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster, Ministry of Education/Joint International Research Laboratory of Climate and Environment Change, Nanjing University of Information Science and Technology, Nanjing 210044, China
    3 National Climate Center, China Meteorological Administration, Beijing 100081, China
  • Received:2020-09-04 Revised:2020-11-01 Online:2021-07-30 Published:2021-08-11
  • Contact: ZHOU Bo-Tao E-mail:1952943140@qq.com;zhoubt@nuist.edu.cn

Abstract:

Based on the Regional Climate Model Version 4 (RegCM4) simulations (named CdR, EdR, HdR, and MdR, respectively) dynamically downscaling from four global climate models (GCMs) as well as the observed high-resolution grid dataset CN05.1, the regional rainstorm events that occurred in China during 1981-2005 were identified by using a “tracing” objective method. On this basis, the fidelity of the RegCM4 downscaling in simulating the climate features of regional rainstorm events in China was evaluated. The results show that the four RegCM4 simulations and their ensemble can reasonably capture the observed annual cycles and climate mean values of the frequency, duration, rainfall amount, extent, and comprehensive intensity of regional rainstorm events averaged in China. They can also well reproduce the probability of duration, rainfall amount, extent and comprehensive intensity of regional rainstorm events in different bands and the climatologically spatial distribution of accumulative frequency, duration and rainfall amount of regional rainstorm events in the observation. The spatial correlations of the simulations with the observation are all above 0.9 and the root-mean-square errors are generally below 0.4. However, the simulations slightly underestimate the frequency of regional rainstorm events, mainly due to the underestimation of moderate regional rainstorm events. The average duration and average rainfall amount are slightly overestimated, while the average extent is slightly underestimated. The comprehensive intensity is overestimated by the simulations (especially by MdR) with the exception of HdR. For spatial distribution, the performance of CdR is relatively lower than that of other simulations. The relative errors of the ensemble simulation with reference to the observation are 13%, 2%, -11%, and 3% for the average duration, rainfall amount, extent, and comprehensive intensity of regional rainstorm events, respectively.

Key words: Regional rainstorm event, Dynamical downscaling, Model evaluation, Climate feature

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