西南地区东部前后冬气温反位相异常特征及成因分析  

Characteristics and Causes Analysis of Anomalous Temperature Reversalin the Eastern Southwest China During Early and Late Winter

作　　者：吴遥 唐红玉[1,2] 董新宁[1,2] 周杰 魏麟骁[1,2] WU Yao;TANG Hongyu;DONG Xinning;ZHOU Jie;WEI Linxiao(CMA Key Open Laboratory of Transforming Climate Resources to Economy,Chongqing 401147;Chongqing Climate Center,Chongqing 401147)

机构地区：[1]中国气象局气候资源经济转化重点开放实验室,重庆401147 [2]重庆市气候中心,重庆401147

出　　处：《气象》2024年第7期847-858,共12页Meteorological Monthly

基　　金：重庆市自然科学基金面上项目(CSTB2022NSCQ-MSX0558);中国气象局创新发展专项(CXFZ2022J031);中国气象局复盘总结专项(FPZJ2023-106);重庆市气象部门人才支持性项目(RCZC-202303)共同资助

摘　　要：利用西南地区东部台站观测和ERA5再分析等资料,分析该地区冬季气温前后冬反位相异常转折(以下简称异常转折)特征及其成因。结果表明:该地区冬季气温在2000年以后易出现前冷后暖(P1型)的异常转折变化,而前暖后冷(P2型)则在20世纪70年代出现最多。冬季气温发生异常转折时,500 hPa位势高度场上反映出青藏高原高度场是最为关键的环流系统,甚至超过了乌拉尔山阻塞高压的影响。200 hPa风场上,西风急流等系统通过影响东亚冬季风进而影响冬季气温季节内变化。海平面气压场上,当蒙古高压在冬季呈显著前强后弱异常变化时,冬季气温易出现P1型异常转折,反之易出现P2型异常转折。冬季气温季节内发生异常转折时,北大西洋、赤道中东太平洋和赤道印度洋海温均表现出较为明显异常信号;当前期夏、秋季这三个海域海温异常偏高时,冬季气温易出现P1型异常转折,反之则易出现P2型异常转折,夏、秋季异常海温可作为预测前兆信号。This study uses observation data from stations in the eastern Southwest China and ERA5 reanalysis data andanalyzes the characteristics and causes of the inverse phase shift anomalies in winter temperatures (referred to asanomalous shifts) in this region. The findings indicate that after 2000, this region tended to experience a pattern ofcolder temperatures earlier in the winter followed by warmer temperatures later (referred to as P1 type), whereas apattern of warmer temperatures followed by colder ones (referred to as P2 type) was more prevalent in the 1970s.During the occurrence of these anomalous shifts in winter temperatures, the 500 hPa geopotential height fieldreveals that the Tibetan Plateau plays a cru- cial role in the circulation system, even surpassing the influence of theUral blocking high. At the 200 hPa wind field, systems such as the westerly jet stream affect the East Asian wintermonsoon influencing the intra-seasonal variation of temperature in winter. In terms of sea-level pressure fields, when the Mongolian highexhibits significant weakening after an initial strengthening in winter, P1 type temperature shifts are more likely tooccur, and vice versa for P2 type shifts. Additionally, during these anomalous temperature shifts within the winterseason, significant anomaly signals have been observed in the North Atlantic, the equatorial central and easternPacific and the equatorial Indian Ocean. High sea surface temperature anomalies in these three areas during thepreceding summer and autumn seasons tend to cause P1 type shifts in winter temperatures, whereas the oppositeconditions tend to result in P2 type shifts. Thus, abnormal sea surface temperature can serve as potential precursorsfor prediction.

关 键 词：西南地区东部 冬季气温 异常转折 成因分析 

分 类 号：P461[天文地球—大气科学及气象学]