Projecting Spring Consecutive Rainfall Events in the Three Gorges Reservoir Based on Triple-Nested Dynamical Downscaling

• Published in: Advances in atmospheric sciences Vol. 41; no. 8; pp. 1539 - 1558
• Main Authors: Zheng, Yanxin, Li, Shuanglin, Keenlyside, Noel, He, Shengping, Suo, Lingling
• Format: Journal Article
• Language: English
• Published: Heidelberg Science Press 01.08.2024; Springer Nature B.V; Nansen-Zhu International Research Centre,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China%Nansen Environmental and Remote Sensing Center and Bjerknes Centre for Climate Research,Bergen 5007,Norway; Nansen Environmental and Remote Sensing Center and Bjerknes Centre for Climate Research,Bergen 5007,Norway; Department of Atmospheric Science,CMA-CUG Joint Centre for Severe Weather and Climate and Hydro-geological Hazards,China University of Geosciences,Wuhan 430074,China; Nansen Environmental and Remote Sensing Center and Bjerknes Centre for Climate Research,Bergen 5007,Norway%Geophysical Institute,University of Bergen and Bjerknes Centre for Climate Research,Bergen 5007,Norway; Three Gorges National Climatological Observatory,Yichang 443099,China%Geophysical Institute,University of Bergen and Bjerknes Centre for Climate Research,Bergen 5007,Norway; Geophysical Institute,University of Bergen and Bjerknes Centre for Climate Research,Bergen 5007,Norway%Institute of Atmospheric Physics and Climate Change Research Center,Chinese Academy of Sciences,Beijing 100029,China
• Subjects: Advection; Atmospheric Sciences; Canyons; Climate; Climate models; Duration; Earth and Environmental Science; Earth Sciences; Fossil fuels; Fossils; Geological hazards; Geophysics/Geodesy; Global climate; Global climate models; Interdisciplinary research; Interdisciplinary studies; Luminous intensity; Meteorology; Ocean; Original Paper; Precipitation; Probability distribution; Rainfall; Rainfall amount; Rainfall duration; Regional development; Reservoirs; Sea Ice and Northern Hemisphere Climate: In remembrance of Professor Yongqi Gao’s key contributions; Spring (season); Uncertainty; Weather forecasting; Three Gorges Reservoir; consecutive rainfall events; triple-nested downscaling; Three Gorges Reservoir area; geological hazards; projection; 三层嵌套; 连阴雨; 地质灾害; 三峡库区; 预估
• ISSN: 0256-1530; 1861-9533
• DOI: 10.1007/s00376-023-3118-2

Spring consecutive rainfall events (CREs) are key triggers of geological hazards in the Three Gorges Reservoir area (TGR), China. However, previous projections of CREs based on the direct outputs of global climate models (GCMs) are subject to considerable uncertainties, largely caused by their coarse resolution. This study applies a triple-nested WRF (Weather Research and Forecasting) model dynamical downscaling, driven by a GCM, MIROC6 (Model for Interdisciplinary Research on Climate, version 6), to improve the historical simulation and reduce the uncertainties in the future projection of CREs in the TGR. Results indicate that WRF has better performances in reproducing the observed rainfall in terms of the daily probability distribution, monthly evolution and duration of rainfall events, demonstrating the ability of WRF in simulating CREs. Thus, the triple-nested WRF is applied to project the future changes of CREs under the middle-of-the-road and fossil-fueled development scenarios. It is indicated that light and moderate rainfall and the duration of continuous rainfall spells will decrease in the TGR, leading to a decrease in the frequency of CREs. Meanwhile, the duration, rainfall amount, and intensity of CREs is projected to regional increase in the central-west TGR. These results are inconsistent with the raw projection of MIROC6. Observational diagnosis implies that CREs are mainly contributed by the vertical moisture advection. Such a synoptic contribution is captured well by WRF, which is not the case in MIROC6, indicating larger uncertainties in the CREs projected by MIROC6.