高原夏季风强弱和南亚高压的关系研究

Relationship between Variation of the Tibetan Plateau Summer Monsoon and South Asian High

为进一步认识高原夏季风和南亚高压的关系,利用1948~2013年NCEP/NCAR日平均再分析资料,采用相关分析和合成分析,探讨高原夏季风异常对南亚高压活动的影响。研究表明,高原夏季风强时,南亚高压中心位置偏东偏南,呈＂青藏高压模态＂,高原夏季风弱时,南亚高压中心偏西偏北,呈＂伊朗高压模态＂。在非绝热加热场上,高原夏季风强时,青藏高原南侧感热偏强,青藏高原以西到伊朗高原东部感热偏弱。高原夏季风弱时,青藏高原南侧及西南侧为感热偏弱,高原西北部感热偏强。值得注意的是,地表感热的正负异常分布与南亚高压中心位置的分布较一致,夏季南亚高压中心位置的变化可能与地表感热加热密切联系。

In order to further acquire the relationship between the Tibetan Plateau Summer Monsoon （TPSM） and South Asian High （SAH）. Using the 66-year （1948-2013） NECP/NCAR daily reanalysis data, the impact of TPSM anomaly on SAH activities are investigated by the correlation analysis and the composite analysis. The results show that a stronger （weaker） TPSM is associated with the center of the SAH shifting eastward （westward） and southward （northward） , and SAH presenting its Tibetan high （Iranian high） pattern. Meanwhile, when TPSM is stronger, sensible heat over south- ern TP has positive anomalies and it over western TP and eastern IP has negative anomalies. When TPSM is weaker, sensible heat over southern TP and southwestern TP has negative anomalies and it over northwestern TP has positive a- nomalies. It＇ s important to note that the distribution of sensible heat anomalies are consistent with SAH＇ s center loca- tion, which reveal that the distribution of SAH＇ s center in summer may be closely associated with sensible heating.