山东省远距离热带气旋暴雨研究

应用1971—2003年的山东降水资料、常规天气图资料、台风年签和NCEP资料，对在华沿海登陆和活动的热带气旋在山东造成远距离暴雨的气候特征进行统计分析，对环流形势场进行合成分析。建立了山东省远距离热带气旋暴雨的天气学模型。分别计算分析了山东有和无远距离热带气旋暴雨合成的水汽和温湿能的收支。结果表明：在华南沿海登陆和活动的热带气旋与西风带环流系统和副热带高压相互作用在山东造成的远距离热带气旋暴雨年均2.5次。暴雨的范围广、强度大。出现暴雨的时间比热带气旋登陆时间滞后。在山东造成远距离暴雨的热带气旋在华南沿海登陆时，中心东部有一股东南风或偏南风低空急流指向内陆。中高纬度中低层西风带环流弱，位置偏北。500 hPa西风带中的偏北气流与副高边缘的偏南气流在山东境内汇合。低层850—700 hPa伴有低值系统影响，山东为气旋性环流控制。热带气旋登陆后其中心附近的中低层偏南风急流向北伸展，绕过副高脊线直达山东。在台风中心附近至山东之间建立起水汽和温湿能的输送通道，把高温高湿的暖湿空气源源不断地向山东输送。在台风登陆后12—48小时内，山东暴雨区上空有大量的水汽和温湿能的净流入。暖湿气流与西风带气流相汇合，产生辐合上升，造成暴雨。

A study of the far distance tropical cyclone torrential rainfalls in Shandong Province

Using data of precipitation in Shandong province,normal meteorological observation data, typhoon yearbooks and NCEP/NCAR data during 1971-2003, the statistical climate characteristics and the composing circumfluence of the torrential rainfalls in Shandong province caused by remote tropical cyclones landing or activating on the coast of South China were analyzed. The synoptic model of the far distance tropical cyclone torrential rainfalls in Shandong province was established. The budgets of composed water vapor and enthalpy of having and not having far distance tropical torrential rainfalls in Shandong were analyzed. The result indicated: the annual average of far distance tropical cyclone torrential rainfalls in Shandong caused by the interaction of the tropical cyclone landing or activating on the coast of South China, the west wind system in middle latitude and the subtropical high is 2.5/year. This torrential rainfall's range was very wide; its intensity was very strong. The torrential rainfalls occurring time were lagged the tropical cyclone landing time. When the tropical cyclone which caused the torrential rainfall in Shandong was landing on the coast of South China, there were south-easterly or southerly jets at the low level of troposphere in the eastern part of center of the tropical cyclones toward Mainland China; westerly circulations at mid-high-latitude were weaker and lay over higher latitudes. The northerly winds in westerly band met the southerly winds on the west edge of subtropical high over western Pacific in Shandong region at 500 hPa. Effected by low system at the lower layer of troposphere (850-700 hPa), Shandong was dominated by cyclonic circulation. After tropical cyclone landing, the southerly jet near the center of cyclone extended northwardly and arrived at Shandong through the ridge line of the subtropical high over western Pacific. The transportation channels of water vapor and enthalpy between the center of tropical cyclone and Shandong was established and the warmer and wetter atmosphere carried toward Shandong continuously. From 12 to 48 hours after tropical cyclone landing, there were a great deal of water vapor and enthalpy importing, the wet and warm airflow and the westerly wind band airflow converged, and then updraft was produced, so the torrential rainfall occurred.