夏季新疆降水异常与印度降水的关系  

Relationships between Rainfall Anomalies in Xinjiang Summer and Indian Rainfall

作　　者：杨莲梅[1] 肖开提.多莱特 张庆云[3] 

机构地区：[1]中国气象局乌鲁木齐沙漠气象研究所,新疆乌鲁木齐830002 [2]新疆气象局,新疆乌鲁木齐830002 [3]中国科学院大气物理研究所,北京100029

出　　处：《高原气象》2009年第3期564-572,共9页Plateau Meteorology

基　　金：国家自然科学基金项目(40775056);科技部公益性行业科研专项(GYHY200706008);中央级公益性科研院所基本科研业务项目(IDM200802)共同资助

摘　　要：利用1960—2003年6~8月新疆75个气象站降水量、印度地区降水量和NCEP/NCAR再分析资料,分析了新疆夏季降水量与印度降水之间的关系,以及印度降水变化与新疆降水异常联系的可能的物理机制。研究表明,印度降水与新疆夏季降水量之间存在显著的反相关关系,它们之间的线性相关系数为-0.39。夏季印度降水变化与其西北侧的西亚—中亚地区对流层平均温度呈显著正相关,从而与对流层高层南亚高压中心东西振荡和高压西部强弱,西亚地区副热带西风急流（西亚急流）强度和南北位置振荡,500 hPa伊朗高压南北和东西振荡密切联系,夏季印度降水变化通过与这些影响新疆降水的系统联系而与新疆夏季降水呈显著的反相关关系。Eliassen-Palm通量（EP通量）的动力学诊断分析进一步表明,印度季风偏强（偏弱）导致南亚高压西侧由南向北进入亚洲西风急流入口处的波作用通量偏强（偏弱）,使得西亚急流偏强（偏弱）、偏北（偏南）。The relationships between the summer rainfall in Xinjiang and Indian rainfall as well as and possible physics mechanism of their relationships are investigated using the monthly rainfall data of India monsoon areas and 75 stations in Xinjiang and NCEP/NCAR reanalysis dataset from June to August 1960--2003. It is found that there is remarkably negative correlation between summer rainfall in Xinjiang and Indian rainfall which the linear correlation coefficient is --0.39. There is prominent positive correlation between Indian rainfall and troposphere temperature over west Asia-middle Asia area which is to the northwest of coagulate latent heat released by India rainfall, as a result, the center of South Asia high （SAH） is favorable for moving westward （eastward） to Iran Plateau （Tibetan Plateau）, the west SAH and west Asia westerly jet stream （WAWJS） strengthens （weakens）. At the same time, heating atmosphere inducing by strong coagulate latent heat brings about Iran high northward and eastward at 500 hPa to extend over Xinjiang, so that it is favorable for less rainfall in Xinjiang. By contrast, cooling atmosphere causing by weak coagulate latent heat induces Iran high southward and westward resulting in the middle Asia low system activity to impress Xinjiang; consequently there is prominent positive correlation between Indian rainfall and summer rainfall in Xinjiang. Further, Eliasson-Palm flux diagnoses confirm that waves activity flux propagation entering into WAWJS along west side of SAH from low latitude to middle latitude is stronger （weaker） than normal while Indian rainfall is more （less） than climatic average resulting in strengthened （weakened） WAWJS.

关 键 词：新疆夏季降水 印度降水 南亚高压 西亚西风急流 

分 类 号：P457.6[天文地球—大气科学及气象学]