广西前汛期大范围持续性暴雨的月际特征及环流差异性分析  

Monthly characteristics and circulation difference analysis of large-scale continuous torrential rain during the pre-flood season in Guangxi

作　　者：吴玉霜 黄小燕[2] 林开平[3] 赵华生[2] 黄颖[2] Wu Yushuang;Huang Xiaoyan;Lin Kaiping;Zhao Huasheng;Huang Ying(Guangxi Teachers Education University,Guangxi Nanning 530001;Guangxi Research Institute of Meteorological Disasters Mitigation,Guangxi Nanning 530022;Guangxi Meteorological Observatory,Guangxi Nanning 530022)

机构地区：[1]广西师范学院,广西南宁530001 [2]广西区气象减灾研究所,广西南宁530022 [3]广西区气象台,广西南宁530022

出　　处：《气象研究与应用》2018年第4期9-13,106,共6页Journal of Meteorological Research and Application

基　　金：国家自然科学基金项目(41575051;41765002);广西自然科学基金重点项目(2017GXNSFDA198030)

摘　　要：基于1961～2017年广西87个地面观测站逐日降水资料,利用NCEP/NCAP逐日再分析资料并综合运用诊断分析方法,从月际变化的角度分析广西前汛期大范围持续性暴雨的气候特征、大气环流特点以及水汽、动力等物理机制的差异。结果表明:(1)广西前汛期大范围持续性暴雨出现频数在4、5和6月份中呈逐月递增趋势。(2)不同月份发生大范围持续性暴雨的影响机制各异,500hPa表现为4月的两槽两脊并在低纬度地区有分裂出的短波槽影响广西;5月为两脊一槽形势;6月份的一槽一脊配合中低纬度的东亚槽。低层850hPa表现为异常的气流辐合,随着月份增加辐合不断加强。(3)4～6月的主要水汽来源和水汽含量各异。(4)4～6月广西上空不稳定能量增强,为广西暴雨的产生提供了有利的触发机制。Based on daily precipitation data of 87 ground observation stations in Guangxi from 1961 to 2017,using NCEP/NCAP daily reanalysis data and the diagnostic analysis methodcomprehensively,from the perspective of monthly changes,to analyze the climatic characteristics,atmospheric circulation characteristics and the differences of physical mechanismsof the large-scale continuous torrential rain in Guangxi during the pre-flood season.The results show that(1) the frequency of largescale continuous torrential rain in Guangxi pre-flood season increases month by month in April,May and June.(2) The impact mechanisms of large-scale persistent rainstorms in different months are all different.At 500 hPa,there are two troughs and two ridges in April and split short-wave troughsat low latitude affects Guangxi;in May,there are two ridges and one trough;a trough and a ridge in June match with the East Asian trough at middle and low latitudes.850 hPa shows abnormal convergence,which strengthens by month.(3) The main water vapor sources and water vapor content vary from April to June.(4) The increase of unstable energy over Guangxi during April to June provides a favorable triggering mechanism for the occurrence of Guangxirainstorm.

关 键 词：前汛期 大范围持续性暴雨 气候特征 影响机制 广西 

分 类 号：P466[天文地球—大气科学及气象学]