气象学报2024，Vol.82Issue(4)：459-475,17.DOI:10.11676/qxxb2024.20230131
西南地区冬季异常冷湿/暖干的气候背景分析
Analysis on the climate circulation patterns for abnormal cold-wet and warm-dry winters in Southwest China
摘要
Abstract
Based on data collected at 409 surface meteorological observation stations in Southwest China(SWC)and reanalysis data from NCEP/NCAR and NOAA from 1981 to 2022,this study analyzes climate change characteristics and formation mechanisms of abnormal cold-wet/warm-dry winter climate patterns in SWC.The results show that cold-wet and warm-dry are the most common climate configurations in SWC during winter.Since the 1980s,the entire region shows a significant increase trend of warm-dry winters.A stronger(weaker)Baikal lake high and a weaker(stronger)Qinghai-Xizang plateau high in the upper and middle troposphere as well as a stronger(weaker)Siberian high in the middle and lower troposphere synergistically form a quasi-barotropic"north positive south negative"("south positive north negative")circulation pattern,which is the key atmospheric circulation background for the cold-wet(warm-dry)winter in SWC.Sea surface temperatures(SSTs)over the area to the south of Aleutian Islands,regions in the southern and northern sides of the eastern equatorial Pacific and the region to the southwest of Australia during autumn are key precursor signals of the circulation background.Higher(lower)SSTs over the area to the south of Aleutian Islands can enhance(weaken)the Azores high continuously from autumn to winter and then strengthen(weaken)the Baikal lake high and the Siberian high with eastward propagation of Rossby waves from the enhanced(reduced)Azores high.Lower(higher)SSTs over the regions in the southern and northern sides of the eastern equatorial Pacific can weaken(strengthen)geopotential height over the low latitudes of the Northeast Pacific and the North Atlantic in winter,which will then trigger positive(negative)abnormal Rossby waves sources that spread eastward by Rossby waves,resulting in lower(higher)Qinghai-Xizang plateau high.Moreover,higher(lower)SSTs in the region to the southwest of Australia can enhance cross-equatorial southerlies(northerlies)in upper levels and subsequently strengthen(weaken)the Middle East jet,leading to lower(higher)Qinghai-Xizang plateau high.关键词
西南地区冬季/冷湿/暖干气候配置/气候背景/青藏高原高压/贝加尔湖高压Key words
Winter climate in SWC/Cold-wet/warm-dry climate configuration/Climate background/Qinghai-Xizang plateau high/Baikal lake high分类
天文与地球科学引用本文复制引用
庞轶舒,周长艳,王顺久,罗玉..西南地区冬季异常冷湿/暖干的气候背景分析[J].气象学报,2024,82(4):459-475,17.基金项目
国家自然科学基金联合基金项目(U2342209)、中国气象局复盘总结专项(FPZJ2024-115)、中国气象局气候预测研究重点开放实验室青年开放课题(CMA-LCPS-23-02)、中国气象局青年创新团队(CMA2024QN06)、国家自然科学基金面上项目(41772173)、高原与盆地暴雨旱涝灾害四川省重点实验室科技发展基金项目(SCQXKJQN20223010)、中国气象局气象能力提升联合研究专项(22NLTSZ005). （U2342209）
