Changes in tropical cyclone response to the Boreal Summer Intraseasonal Oscillation in the western North Pacific under global warming in EC-Earth3P-HR  

作　　者：Zhefan Gao Chaoxia Yuan 

机构地区：[1]Key Laboratory of Meteorological Disaster of Ministry of Education,Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Institute for Climate and Application Research(ICAR),Nanjing University of Information Science&Technology,Nanjing,China [2]Application Laboratory,Japan Agency of Marine-Earth Science and Technology,Yokohama,Japan

出　　处：《Atmospheric and Oceanic Science Letters》2025年第2期22-28,共7页大气和海洋科学快报(英文版)

基　　金：financially supported by the National Natural Science Foundation of China[grant number 42088101]。

摘　　要：EC-Earth3P-HR reproduces well the observed Boreal Summer Intraseasonal Oscillation(BSISO)and its impacts on tropical cyclone genesis(TCG)in the western North Pacific(WNP).Hence,the historical simulation(1950-1979)and future projection under the SSP5-8.5 scenario(2020-2049)in EC-Earth3P-HR are adopted to explore possible changes in the BSISO’s modification of WNP TCG under global warming to enhance the understanding of TC activities in the WNP.Results show that the BSISO circulation in the WNP shifts northeastward under global warming.This leads to enhanced convection in a northwest-southeast-oriented band crossing the WNP.Along the band,the BSISO-related TCG anomalies are enhanced.Analyses of genesis potential index show that changes in the BSISO-related mid-tropospheric relative humidity play the dominant role in modifying the BSISO’s impacts on WNP TCG under global warming.The enhanced BSISO convection in the band moistens the middle troposphere,which helps reduce the entrainment of generally dry mid-tropospheric air in the updrafts and the modification of the boundary layer by the downdraft of generally dry mid-tropospheric air,leading to enhanced TCG.北半球夏季季内振荡(BSISO)对西北太平洋(WNP)热带气旋形成(TCG)有显著的影响,并且为TC的次季节预报提供重要依据,因此研究其在全球变暖下的变化有重要意义.EC-Earth3P-HR模式较好地再现了观测到的BSISO及其对TCG的影响.因此,采用EC-Earth3P-HR的历史模拟(1950–1979)和SSP5-8.5情景(2020–2049)下的未来预估,探讨全球变暖下BSISO对WNP上TCG调制的可能变化.结果表明,在全球变暖影响下,WNP上的BSISO环流向东北方向移动,表现为西北-东南方向分布的增强对流带.在对流带上,BSISO相关的TCG异常增强.成因潜力指数分析表明,全球变暖背景下,与BSISO相关的对流层中部相对湿度的变化对BSISO对TCG的调制起主导作用.带内增强的BSISO对流使对流层中部空气变湿润,这有利于减少上升气流对通常干燥的对流层空气的夹带以及下沉气流对边界层的修正,从而导致TCG的增强.

关 键 词：Global warming Tropical cyclones BSISO 

分 类 号：P73[天文地球—海洋科学]