{"title":"两种El Niño对南极半岛和南极西部春季降水的显著影响","authors":"Xueyang Chen , Shuanglin Li , Chao Zhang","doi":"10.1016/j.aosl.2023.100387","DOIUrl":null,"url":null,"abstract":"<div><p>Based on multiple reanalysis data, the authors investigated the distinct impacts of central Pacific (CP) and eastern Pacific (EP) El Niño events on precipitation over West Antarctica and the Antarctic Peninsula in austral spring (September–November). The results demonstrate that EP and CP events have similar impacts on precipitation over the Amundsen–Bellingshausen seas, but opposite impacts on that over the Weddell Sea, especially the Antarctic Peninsula. Mechanistically, the tropical heat sources associated with EP events drive two branches of Rossby wave trains, causing an anomalous anticyclone and cyclone over the Ross–Amundsen–Bellingshausen seas and the Weddell Sea, respectively. Anomalous southerly winds to the east (west) of the anomalous anticyclone (cyclone) advect colder and drier air into the Bellingshausen–Weddell seas and the Antarctic Peninsula, which jointly result in negative precipitation anomalies there. CP events, however, trigger only one weak and westward-shifted Rossby wave train, which induces an anomalous anticyclone and cyclone in the Ross–Amundsen seas and Bellingshausen–Weddell seas, respectively, both 20°–30° west of those generated by EP events. Consequently, anomalous northerly (southerly) winds to the east (west) of the anomalous cyclone cause an increase (a decrease) in precipitation over the Weddell Sea (Amundsen–Bellingshausen seas).</p><p>摘要</p><p>本文基于多种再分析资料, 研究了中部型 (CP) 和东部型 (EP) El Niño事件对南半球春季 (9–11月) 西南极和南极半岛降水的不同影响. 结果显示, EP和CP事件对阿蒙森-别林斯高晋海的降水具有相似影响, 而对威德尔海, 特别是南极半岛的降水影响相反. 由于EP事件激发两支罗斯贝波列, 分别引起罗斯-阿蒙森-别林斯高森海和威德尔海上空的异常反气旋和气旋, 从而导致别林斯高晋-威德尔海和南极半岛受到干冷的异常偏南风影响, 降水减少. 然而, CP事件仅激发一支相对较弱且偏西的罗斯贝波列, 分别引起罗斯-阿蒙森海和别林斯高晋-威德尔海上空的异常反气旋和气旋, 从而导致南极半岛以西 (东) 受异常偏南 (北) 风影响, 降水减少 (增加).</p></div>","PeriodicalId":47210,"journal":{"name":"Atmospheric and Oceanic Science Letters","volume":null,"pages":null},"PeriodicalIF":2.3000,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"Distinct impacts of two kinds of El Niño on precipitation over the Antarctic Peninsula and West Antarctica in austral spring\",\"authors\":\"Xueyang Chen , Shuanglin Li , Chao Zhang\",\"doi\":\"10.1016/j.aosl.2023.100387\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Based on multiple reanalysis data, the authors investigated the distinct impacts of central Pacific (CP) and eastern Pacific (EP) El Niño events on precipitation over West Antarctica and the Antarctic Peninsula in austral spring (September–November). The results demonstrate that EP and CP events have similar impacts on precipitation over the Amundsen–Bellingshausen seas, but opposite impacts on that over the Weddell Sea, especially the Antarctic Peninsula. Mechanistically, the tropical heat sources associated with EP events drive two branches of Rossby wave trains, causing an anomalous anticyclone and cyclone over the Ross–Amundsen–Bellingshausen seas and the Weddell Sea, respectively. Anomalous southerly winds to the east (west) of the anomalous anticyclone (cyclone) advect colder and drier air into the Bellingshausen–Weddell seas and the Antarctic Peninsula, which jointly result in negative precipitation anomalies there. CP events, however, trigger only one weak and westward-shifted Rossby wave train, which induces an anomalous anticyclone and cyclone in the Ross–Amundsen seas and Bellingshausen–Weddell seas, respectively, both 20°–30° west of those generated by EP events. Consequently, anomalous northerly (southerly) winds to the east (west) of the anomalous cyclone cause an increase (a decrease) in precipitation over the Weddell Sea (Amundsen–Bellingshausen seas).</p><p>摘要</p><p>本文基于多种再分析资料, 研究了中部型 (CP) 和东部型 (EP) El Niño事件对南半球春季 (9–11月) 西南极和南极半岛降水的不同影响. 结果显示, EP和CP事件对阿蒙森-别林斯高晋海的降水具有相似影响, 而对威德尔海, 特别是南极半岛的降水影响相反. 由于EP事件激发两支罗斯贝波列, 分别引起罗斯-阿蒙森-别林斯高森海和威德尔海上空的异常反气旋和气旋, 从而导致别林斯高晋-威德尔海和南极半岛受到干冷的异常偏南风影响, 降水减少. 然而, CP事件仅激发一支相对较弱且偏西的罗斯贝波列, 分别引起罗斯-阿蒙森海和别林斯高晋-威德尔海上空的异常反气旋和气旋, 从而导致南极半岛以西 (东) 受异常偏南 (北) 风影响, 降水减少 (增加).</p></div>\",\"PeriodicalId\":47210,\"journal\":{\"name\":\"Atmospheric and Oceanic Science Letters\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.3000,\"publicationDate\":\"2023-09-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Atmospheric and Oceanic Science Letters\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1674283423000739\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"METEOROLOGY & ATMOSPHERIC SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Atmospheric and Oceanic Science Letters","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1674283423000739","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"METEOROLOGY & ATMOSPHERIC SCIENCES","Score":null,"Total":0}
引用次数: 1
摘要
基于多个再分析资料,研究了中太平洋(CP)和东太平洋(EP) El Niño事件对南极南部春季(9 - 11月)西南极洲和南极半岛降水的显著影响。结果表明,EP和CP事件对阿蒙森-别令斯豪森海降水的影响相似,而对威德尔海特别是南极半岛降水的影响相反。从机制上讲,与EP事件相关的热带热源驱动了罗斯比波列的两个分支,分别在罗斯-阿蒙森-别林斯高森海和威德尔海上空造成了异常的反气旋和气旋。异常反气旋(气旋)东(西)的异常偏南风将较冷、较干的空气平流到别灵高森-威德尔海和南极半岛,共同造成该地区的负降水异常。然而,CP事件只触发了一个弱的、向西移动的罗斯比波列,分别在Ross-Amundsen海和Bellingshausen-Weddell海诱发了一个异常的反气旋和气旋,它们都是由EP事件产生的,在20°-30°以西。因此,异常气旋东面(西面)的异常北风(南风)导致威德尔海(阿蒙森-别令斯豪森海)降水增加(减少)。摘要本文基于多种再分析资料,研究了中部型(CP)和东部型(EP)厄尔尼诺事件对南半球春季(9 - 11月)西南极和南极半岛降水的不同影响。结果显示,EP和CP事件对阿蒙森——别林斯高晋海的降水具有相似影响,而对威德尔海,特别是南极半岛的降水影响相反。由于EP事件激发两支罗斯贝波列,分别引起罗斯-阿蒙森——别林斯高森海和威德尔海上空的异常反气旋和气旋,从而导致别林斯高晋-威德尔海和南极半岛受到干冷的异常偏南风影响,降水减少。然而,CP事件仅激发一支相对较弱且偏西的罗斯贝波列,分别引起罗斯-阿蒙森海和别林斯高晋-威德尔海上空的异常反气旋和气旋,从而导致南极半岛以西(东)受异常偏南(北)风影响,降水减少(增加)。
Distinct impacts of two kinds of El Niño on precipitation over the Antarctic Peninsula and West Antarctica in austral spring
Based on multiple reanalysis data, the authors investigated the distinct impacts of central Pacific (CP) and eastern Pacific (EP) El Niño events on precipitation over West Antarctica and the Antarctic Peninsula in austral spring (September–November). The results demonstrate that EP and CP events have similar impacts on precipitation over the Amundsen–Bellingshausen seas, but opposite impacts on that over the Weddell Sea, especially the Antarctic Peninsula. Mechanistically, the tropical heat sources associated with EP events drive two branches of Rossby wave trains, causing an anomalous anticyclone and cyclone over the Ross–Amundsen–Bellingshausen seas and the Weddell Sea, respectively. Anomalous southerly winds to the east (west) of the anomalous anticyclone (cyclone) advect colder and drier air into the Bellingshausen–Weddell seas and the Antarctic Peninsula, which jointly result in negative precipitation anomalies there. CP events, however, trigger only one weak and westward-shifted Rossby wave train, which induces an anomalous anticyclone and cyclone in the Ross–Amundsen seas and Bellingshausen–Weddell seas, respectively, both 20°–30° west of those generated by EP events. Consequently, anomalous northerly (southerly) winds to the east (west) of the anomalous cyclone cause an increase (a decrease) in precipitation over the Weddell Sea (Amundsen–Bellingshausen seas).