近40年江浙沪及其周边地区可降水量的时空分布特征

The spatial and temporal feature of precipitable water vapor over Jiangsu,Zhejiang,Shanghai and their surrounding areas in recent 40 years

为了深入地认识江浙沪地区气候变化趋势与该区的极端气候,利用ECMWF提供的可降水量数据,运用Mann-Kendall检验法对可降水量的时间变化趋势及突变进行分析,并分析了极端年份可降水量的时空特征.结果表明:1)可降水量季节分布不均,夏高冬低.2)海陆对比明显:春夏海洋可降水量小于大陆,冬季海洋可降水量大于陆地;2006年之前海洋上空可降水量小于大陆上空,2006年之后,出现了逆转.3)1998年春夏、2004年夏秋、2016年春秋季节可降水量距平显著偏高或偏低,与研究区洪涝和干旱灾害相应.这3 a可降水量异常偏高或偏低的时段与区域洪涝和干旱在时间上也比较一致.

In order to understand the trend of climate change in Jiangsu,Zhejiang and Shanghai and the extreme climate in this area deeply,it was analyzed the trend and change of precipitable water vapor（ PWV）with Mann-Kendall（ M-K） test by using the data of PWV provided by ECMWF and the spatial and temporal characteristics of PWV in extreme years. The results showed that： 1） the seasonal distribution of PWV in the study area was uneven and the PWV of summer was higher than that of winter. 2） the sea-land PWV contrast showed seasonal and inter annual variations. The PWV over sea surface was less than that over land surface in spring and summer which tended to be opposite in winter. The annual precipitable water over sea surface was less than that over land surface prior to 2006. However,after 2006,there was a reverse phenomenon. 3） in spring and summer of 1998,summer and autumn of 2004,spring and autumn of 2016,the PWV anomaly was significant,and there were regional differences. The period of high or low PWV anomalies was also consistent with the regional floods and drought in time.