摘要
利用NCEP/NCAR逐日再分析资料和辽宁省逐日站点降水资料,分析了2015年初夏辽宁降水异常偏少的大尺度环流特征。结果表明:2015年初夏是1962年以来辽宁同期降水最少的年份。2015年初夏辽宁降水异常偏少的大尺度环流特征并不是共性,高空急流、西太副高的强度和位置以及是否有西南暖湿气流输送在6个典型少雨年里各有不同。大尺度环流系统的异常配置是导致2015年初夏辽宁降水严重偏少的主要原因,高空急流较气候平均偏南偏强,辽宁位于急流轴以北,高层辐合不利于上升运动发展;西太平洋副热带高压较气候平均偏东偏南,冷空气位置偏北,辽宁缺少冷暖空气交绥;低空急流较气候平均偏东偏南,辽宁缺少暖湿水汽输送及低层辐合上升运动。2015年初夏辽宁降水异常偏少与北太平洋海表面温度“东高西低”导致的大规模上升和下沉运动密切相关。
Based on the NCEP/NCAR daily reanalysis data and daily rainfall data of 53 stations in Liaoning province,circulation characteristics of little rainfall in Liaoning province during earlysummer in 2015 were analyzed.The results showed that the rainfall was seriously less,which is the most serious events for the same period since 1962.Mutual disposition of large-scale circulation in higher and lower levels was the primary circulation cause of seriously little rainfall in Liaoning province during early summer in 2015.The upper jet stream is more southerly and stronger than the climatic,Liaoning province was located in the north of upper jet stream axis,which was not in favor of the development upward movement.The location of the west Pacific subtropical high was to the south and east compared with the climatic,the cold air was to the north compared with the climatic,so cold and warm air didn’t meet in Liaoning province.The location of lower jet stream was more southward and eastward than the climatic,lacking of warm and wet airflow transportation,convergence,and ascending motion.The precipitation anomaly of Liaoning province in early summer of 2015 was closely related to large scale rising and sinking motion caused by the“higher east and lower west”pattern of the north Pacific sea surface temperature.Further analysis showed that large scale circulation in early summer was not universal,the intensity and position of upper jet stream and west Pacific subtropical high,whether existing warm and wet air transport varied over six typical years.
作者
焦敏
李辑
胡春丽
周斌
黄岩
JIAO Min;LI Ji;HU Chunli;ZHOU Bin;HUAGN Yan(Ecological Meteorology and Satellite Remote Sensing Center of Liaoning Province,Shenyang 110166,China)
出处
《沙漠与绿洲气象》
2019年第6期73-81,共9页
Desert and Oasis Meteorology
基金
国家重点研发计划课题(2018YFC1505601)
国家自然科学基金(41605087)
辽宁省科学事业公益研究基金(20180050)
辽宁省气象局科学技术研究课题(BA201907)。
关键词
降水异常
大尺度环流
辽宁
初夏
precipitation anomaly
large scale circulation
Liaoning province
earlysummer
作者简介
焦敏(1987—),女,工程师,主要从事气候变化及农业气象研究。E-mail:minminjiao2006@163.com;通讯作者:李辑(1963—),男,正研级高级工程师,主要从事气候变化及农业气象研究。E-mail:cqliji@sina.com。
