粤东暴雨中心前汛期降水异常的环流特征及前兆性信号分析  

On the circulation feature of early rainy season and its precursors in storm center of eastern Guangdong

作　　者：李明华 李超 陈芳丽[3] 郑群峰 陈潜[1,4] 张超 赵春阳[1,4] 周佐欢 LI Minghua;LI Chao;CHEN Fangli;ZHENG Qunfeng;CHEN Qian;ZHANG Chao;ZHAO Chunyang;ZHOU Zuohuan(Meteorological Bureau of Shenzhen Municipality,Shenzhen 518040,China;Shenzhen Key Laboratory of Severe Weather in South China,Shenzhen 518040,China;Meteorological Bureau of Huizhou,Huizhou 516001,China;Shenzhen National Climate Observatory,Shenzhen 518040,China)

机构地区：[1]深圳市气象局(台),广东深圳518040 [2]深圳南方强天气研究重点实验室,广东深圳518040 [3]惠州市气象局,广东惠州516001 [4]深圳市国家气候观象台,广东深圳518040

出　　处：《中山大学学报（自然科学版）》2020年第5期113-125,共13页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：广东省科技计划项目(2019B020208016,2016A020223016,2019A1515010814);国家自然基金(91544102,41405047);中国气象局预报员专项(CMAYBY2020-091)。

摘　　要：研究了1967~2018年粤东暴雨中心前汛期降水的年际变化,以及降水异常对应的环流异常特征,并对降水异常的前兆性信号特征进行分析。研究结果表明:1990年以后粤东暴雨中心前汛期降水年际变率增强,2005年以后降水偏多年异常增多。降水异常年的环流特征差异显著,偏多年对流层中上层高空急流增强,副热带高压范围偏大西脊点偏西,东亚大槽偏深,江南地区偏南风减弱,有利于粤东辐合增强;偏少年高空急流减弱位置偏北,副热带高压范围偏小,大陆高压增强,底层我国东部地区偏南风一致减弱,不利于粤东辐合。降水偏多(偏少)年的前兆性信号主要表现为极地海冰偏少(偏多)以及赤道东太平洋暖(冷)海温异常。进一步研究表明,高空急流以及东亚大槽和前期极地海冰异常有关,而副热带高压和前期赤道东太平洋海温有关。The interannual variation of early rainy season precipitation over the storm center of eastern Guangdong from 1967 to 2018,and the association with the large-scale atmospheric circulation characteristics and the precursory oceanic conditions were analyzed in this present paper.The interannual variation has strengthened since 1990 s.The years with rainfall amount above normal have occurred more frequently since 2005.The circulation features were significantly between wet and dry years.The atmospheric conditions of enhanced upper-tropospheric jet,the larger subtropical high area than normal,the deepened East Asian trough,as well as the weakened southerly wind over Jiangnan area were favorable for the convergence over the storm center of eastern Guangdong in wet years.The atmospheric features of northward shift of upper-tropospheric jet,the smaller subtropical high area,strengthened continental high over East Asia,and consistent weakened southerly winds went against the convergence over the storm center of eastern Guangdong in dry years.The less(more)ice concentration in polar area and warm(cold)SST over eastern Pacific Ocean were the most significant precursors responsible for the precipitation anomalies.Further investigation showed the significant relation between ice concentration in polar area and upper-tropospheric jet,East Asian trough.On the other hand,the strong association between SST over eastern Pacific Ocean and subtropical high over western Pacific was also confirmed.

关 键 词：前汛期降水 高空急流 副热带高压 极地海冰 赤道东太平洋海温 粤东暴雨中心 

分 类 号：P448[天文地球—大气科学及气象学]