厄尔尼诺现象对西藏5月降水的影响

Effect of El Nino on may precipitation of Tibet

利用1979—2017年NOAA海温距平场数据、NCEP/DOE风场和大气可降水量场数据以及PREC/L降水数据对厄尔尼诺现象影响西藏5月降水进行了分析。结果表明,厄尔尼诺发生年,中南半岛700hPa出现反气旋环流差值,形成下沉气流,大气可降水量偏少,西藏降水偏少;拉尼娜发生年,中南半岛700 hPa出现气旋环流差值,形成上升气流,大气可降水量偏多,西藏降水偏多。

Based on the data of NOAA sea surface temperature anomaly field,NCEP/DOE wind field,atmospheric perceptible water field data and PREC/L precipitation data from 1979 to 2017,the effects of El Ni?o on May precipitation of Tibet were analyzed. The results shows that during the year of El Ni?o,there is an anti-cyclone circulation deviation at 700 hPa in the Indo-China peninsula,which form subsidences,and there is less perceptible water in the atmosphere and less rainfall in Tibet. In the year of La Nina,a cyclone in the Indo-China peninsula occurs at 700 hPa,resulting in updrafts. The amount of perceptible water in the atmosphere is high,and precipitation in Tibet is high.