摘要
利用1961~2019年中国东北地区测站逐日降水资料、美国国家环境预报中心/大气研究中心的月平均再分析资料、NOAA重构的月平均海温和向外长波辐射资料,采用统计诊断方法,从年际时间尺度上分析了东北春季透雨早晚环流特征和前期海温,尤其是热带印度洋海温强迫的联系。结果表明:春季透雨日期与4月降水量的变化具有显著的一致性,典型透雨偏早年的开始时间集中在4月中下旬,偏晚年的开始时间集中在5月中下旬;4月东北亚上空500 hPa位势高度场上,若呈自西向东的“-+”异常环流分布,东北地区以偏南风和气旋性环流为主,有利于水汽输送,春季透雨开始偏早,反之,春季透雨开始偏晚;2~3月热带印度洋暖海温异常是中国东北地区春季透雨偏早的重要稳定影响源之一,其可能机制是,若热带印度洋全区一致海温模态呈正位相,有利于4月西北太平洋地区呈异常反气旋,东北亚地区500 hPa环流异常类似春季透雨偏早年形势,东北地区位于200 hPa西风急流出口区右侧,垂直上升运动增强,呈现出多雨形势。
We analyzed the climatic characteristics of early and late years of spring soaking rain(SSR) in Northeast China(NEC) and the relationship with sea surface temperature(SST) especially the tropical Indian Ocean SST forcing from the interannual time scale on the basis of the daily precipitation data from 1961 to 2019 at stations in NEC, monthly mean data of the National Centers for Environmental Prediction/National Center for Atmospheric Research(NCEP/NCAR) reanalysis, sea surface temperature(SST) data reconstructed using NOAA, and outgoing longwave radiation(OLR) data using statistical diagnostic methods such as causal analysis, correlation analysis and regression analysis. Results showed that the onset date of SSR and April precipitation were considerably consistent. The onset date of typical SSR was concentrated in mid–late April during the early years(1964, 1968, 1969, 1979, 1983, 1988, 1990,1991, 1999, 2002, 2005, 2010, 2013, 2015, 2016) and in mid–late May during late years(1965, 1970, 1971, 1972, 1985,1986, 1989, 1993, 1994, 1997, 2001, 2003, 2006, 2014, 2017, 2019). If 500-hPa geopotential height fields over Northeast Asia in April showed a “-+” anomalous circulation distribution from west to east with southerly winds and cyclonic circulation dominating in Northeast Asia, which were conducive to water vapor transport, SSR started early, and vice versa. The warm sea surface temperature anomaly(SSTA) in the tropical Indian Ocean during February–March was one of the important sources of stable influence in the early years of the SSR in NEC. The possible impact mechanism was that the Indian Ocean Basin warming(IOBW) in a positive phase was favorable to the anomalous anticyclone in Northwest Pacific during April and the 500-hPa atmospheric circulation anomaly over Northeast Asia was similar to that of the early years of SSR. The NEC was situated in the right of the 200-hPa westerly jet stream exit area with an enhanced vertical upward motion, resulting in increased precipitation.
作者
徐士琦
刘刚
杨雪艳
廉毅
刘柏鑫
房一禾
胥珈珈
Shiqi XU;Gang LIU;Xueyan YANG;Yi LIAN;Baixin LIU;Yihe FANG;Jiajia XU(Climate Center of Jilin Province,Changchun 130062;Emergency Warning Information Distribution Center of Jilin Province,Changchun 130062;Regional Climate Center of Shenyang,Shenyang 110016;Key Open Laboratory of Northeast Cold Vortex Research,Shenyang 110016;Laboratory of Research for Middle–High Latitude Circulation System and East Asian Monsoon,Changchun 130062;Baishan Meteorological Bureau of Jilin Province,Baishan 134300)
出处
《大气科学》
CSCD
北大核心
2022年第4期873-885,共13页
Chinese Journal of Atmospheric Sciences
基金
国家自然科学基金项目41975101、41630424、41875119、42005037
中国气象局创新与发展专项CXFZ2021J022
辽宁省自然科学基金项目博士启动研究基金2019-BS-214
吉林省气象局科研课题项目201711。
