沱沱河冬季降水对北极涛动的响应  

Response of Winter Precipitation in the Tuotuo River to the Arctic Oscillation

作　　者：邵骏 彭万兵 梅同单 张智敏 段仙琼 SHAO Jun;PENG Wan-bing;MEI Tong-dan;ZHANG Zhi-min;DUAN Xian-qiong(Bureau of Hydrology,Changjiang Water Resources Commission,Wuhan 430010,China)

机构地区：[1]长江水利委员会水文局,武汉430010

出　　处：《长江科学院院报》2025年第3期188-192,201,共6页Journal of Changjiang River Scientific Research Institute

基　　金：第二次青藏高原综合科学考察研究项目(2019QZKK0203)。

摘　　要：沱沱河冬季降水直接影响高原积雪,并通过热通量和辐射通量影响局地气候和大气环流。采用北极涛动指数提取了北极涛动正、负异常年份,研究了北极涛动异常对沱沱河站冬季降水的丰枯影响,分析了沱沱河站冬季降水与北极涛动间的多时间尺度相关关系,并探讨了沱沱河冬季降水对北极涛动异常的可能响应机制。研究结果表明,长江源区沱沱河站冬季降水受北极涛动影响较为明显,两者之间存在年代际尺度上的显著正相关:①对于北极涛动正异常年,对应沱沱河站冬季降水偏丰概率较大。冬季北极涛动正异常年,高原东亚冬季风减弱,高原南部南支槽(印缅槽)增强,使得来自北印度洋、孟加拉湾的西南暖湿气流相对偏强,导致降水偏多。②对于北极涛动负异常年,对应沱沱河站冬季降水偏枯概率较大;冬季北极涛动负异常年,高原冬季风偏强,引起南支槽减弱,西南暖湿气流相对偏弱,水汽难以北上进入高原,导致降水明显减少。Winter precipitation in the Tuotuo River directly affects plateau snow cover,through heat and radiation fluxes,impacts the local climate and atmospheric circulation.We utilized the Arctic Oscillation Index to identify the years with positive and negative arctic oscillation anomalies and investigated the effects of these anomalies on winter precipitation at Tuotuo River meteorological station.We also analyzed the multi-time scale correlation between winter precipitation and arctic oscillation,and explored the possible response mechanism of winter precipitation to arctic oscillation anomalies.Results indicate that winter precipitation at Tuotuo River station is significantly affected by arctic oscillation,with a notable positive correlation on inter-decadal scale.Positive-anomaly years of arctic oscillation coincide with higher probability of abundant winter precipitation.This can be attributed to the weakening of east Asian winter monsoon over the plateau and the strengthening of the India-Burma trough in the southern part of the plateau which enhance the southwest warm and humid airflows from the northern Indian Ocean and the Bay of Bengal.Conversely,negative-anomaly years of arctic oscillation correspond with scarce winter precipitation.Because in negative-anomaly years,winter monsoon on the plateau intensifies,while the India-Burma trough weakens.As a result,the southwest warm and humid airflows are relatively weaker,hindering the northward movement of water vapor onto the plateau and causing a significant reduction in precipitation.

关 键 词：北极涛动 冬季降水 交叉小波分析 沱沱河 

分 类 号：P333[天文地球—水文科学] TV211[水利工程—水文学及水资源]