中国台风降水的气候特征

CLIMATIC CHARACTERISTICS OF TYPHOON PRECIPITATION OVER CHINA

关键词:  台风降水  变化趋势  台风暴雨

Key words:  typhoon precipitation  long-term trends  typhoon torrential rain

摘要:

对中国台风降水的时空分布特征进行研究,发现台风降水分布在中国中东部广大地区,台风降水量自东南沿海向西北内陆逐渐减少。台风降水最大值出现在台湾岛的中东部地区和海南岛的个别地区,年平均台风降水量大于700mm,最小值出现在内蒙古、山西、陕西、四川的部分地区,年平均台风降水量不足10mm。台风降水一般出现在4～12月,峰值出现在8月。1957～2004年期间台风降水呈下降趋势。台风降水的异常主要由于亚洲地区大气环流和赤道中东太平洋沃克环流的异常变化所引起。进一步分析发现,台风降水在中国大部分地区为减少趋势,且这种趋势在台湾岛、海南岛、东南沿海部分地区和东北南部较显著。台风暴雨是我国东南沿海及部分内陆地区的极端强降水事件之一,这些地区的暴雨和大暴雨很大程度上是台风带来的。

Abstract:

The spatio-temporal characteristics of typhoon precipitation over China were analyzed in this paper.Results show that typhoon precipitation covers most of central-eastern China.Typhoon precipitation gradually decreases from the southeastern coastal regions to the northwestern mainland.The maximum annual typhoon precipitation exceeds 700mm in central-eastern Taiwan and locations of Hainan,while the minimum annual typhoon precipitation occur in parts of Inner Mongolia,Shaanxi,Shanxi and Sichuan,with values less than 10mm.Generally,typhoons produce precipitation over China during April-December,with maximum amount appearing in August.The annual typhoon precipitation time series for stations were examined for the long-term trends.Results show that decreasing trends exist in most of the stations and are statistically significant in parts of Taiwan,Hainan,the southeastern coastal regions and the southern Northeast.Typhoon torrential rain is one of the extreme rainfall events in the southeastern coastal regions and parts of central mainland.In these regions,torrential rains are mostly caused by typhoons.