大气科学2017，Vol.41Issue(3)：561-577,17.DOI:10.3878/j.issn.1006-9895.1609.16163
索马里急流与南亚高压年代际变化的可能联系
The Correlation of Somali Jet Strength with South Asia High on Interdecadal Timescale
摘要
Abstract
The relationship between the Somali jet strength and the summertime South Asia high on interdecadal timescale is analyzed using the nearly 60-y NCEP/NCAR reanalysis data.The results are shown as follows.On interdecadal timescale,positive correlation between Somali jet strength and South Asia high is found.If the Somali jet strength is weak (strong),the summertime South Asia high is also weak (strong) and retreats westward (advances eastward).In different interdecadal backgrounds of Somali jet strength,meridional circulations of the eastern (75°-120°E) and western (20°-70°E) South Asia high are just opposite.During the period when the Somali jet is weak,the meridional circulation of the western South Asia high is strong,whereas the meridional circulation of the eastern South Asia high is dramatically weak,and vice versa.Meanwhile,zonal circulations to the south (20°-27.5°N) and north (27.5°-35°N) of the South Asia high also change differently.The zonal circulation of the northern South Asia high over the Tibetan Plateau is weaker (stronger) than normal,while the zonal circulation of the southern South Asia high over Iranian Plateau is significantly weaker (stronger) than normal during the stronger (weaker) Somali jet period.Further studies verify that the interdecadal relationship between the Somali jet strength and South Asia high is related to the Pacific Decadal Oscillation (PDO).The phase transition of PDO first changes the subtropical westerly jet on interdecadal time scale,which causes the interdecadal variation in the strength of the South Asia high and the tropical easterly jet over the tropical northern Indian Ocean.The tropical easterly jet then sends signals of anomalies to lower level of the atmosphere by the zonal circulation over the tropical Indian Ocean.Finally,the strength of the Somali jet changes.关键词
索马里急流强度/南亚高压/年代际变化/太平洋年代际振荡/纬向东风Key words
Somali jet strength/South Asia high/Interdecadal variability/Pacific Decadal Oscillation (PDO)/Zonal easterlies分类
天文与地球科学引用本文复制引用
石文静,肖子牛,孙杭媛..索马里急流与南亚高压年代际变化的可能联系[J].大气科学,2017,41(3):561-577,17.基金项目
国家自然科学基金项目91637208、41375069、41175051,云南省重点基金项目2016FA041 （）
National Natural Science Foundation of China (Grants 91637208,41375069,41175051),the Key Fund Project of Yunnan Province (Grant 2016FA041) （Grants 91637208,41375069,41175051）
