大气科学2025，Vol.49Issue(5)：1407-1421,15.DOI:10.3878/j.issn.1006-9895.2404.23141
斜脊斜槽与瞬变波相互作用对我国干旱半干旱区极端低温事件的影响
Interactions between Tilted Ridge-Trough and Transient Waves and Their Impact on Extreme Low-Temperatures Events in the Arid and Semiarid Regions of China
摘要
Abstract
This study used the ERA5 reanalysis data to investigate the atmospheric circulation configurations and their evolution processes for three types of extreme low-temperature events in the arid and semiarid regions of China(hereinafter referred to as"dryland")during the winter half-year(November-March).The activity characteristics of transient eddies under different circulation configurations and their feedback forcing the abnormal circulation were examined.The results showed that the continuous amplification of the tilted ridge and trough systems over the Eurasian Continent was the key factor causing extreme low-temperature events in the dryland.This ridge-trough pair was primarily maintained by the incoming low-frequency Rossby wave energy.Under its influence,transient eddies were abnormally active on the southern and northern sides of the tilted ridge and trough.The transient eddies to the south of the trough guided a part of the cold air masses southward,further intensifying the extreme low-temperature events.In addition,the convergence and divergence of transient vorticity fluxes favored the continuous maintenance of the tilted ridge and trough.This condition was conducive to the amplification and eastward expansion of the low-level Siberian cold high pressure,resulting in extreme low temperatures over the entire dryland.When the tilted ridge and trough were elongated longitudinally,the ridge over the Ural Mountains weakened and moved eastward as a Rossby wave,emitting energy downward.Correspondingly,the low-level Siberian cold high pressure also exhibited an eastward displacement,and the activity of the transient waves was suppressed.The extreme low temperatures were mainly confined to the eastern dryland.关键词
斜槽斜脊/瞬变波/极端低温/寒潮/干旱半干旱区Key words
Tilted ridge and trough/Transient eddy/Extreme low-temperature/Cold wave/Arid and semi-arid region分类
天文与地球科学引用本文复制引用
李妍,谢作威,丁敏,布和朝鲁,王月,韩琛惠,苏同华..斜脊斜槽与瞬变波相互作用对我国干旱半干旱区极端低温事件的影响[J].大气科学,2025,49(5):1407-1421,15.基金项目
国家自然科学基金项目41875078,山西省气象局项目SXKMSQH20226313,福建省自然科学基金项目2022J01441 National Natural Science Foundation of China(Grant 41875078),Program of Shanxi Meteorological Administration(Grant SXKMSQH20226313),Natural Science Foundation of Fujian Province of China(Grant 2022J01441) （Grant 41875078）
