2018年金华地区冬季异常降水的水汽输送特征

Water vapor transport characteristics of winter abnormal precipitation in Jinhua area in 2018

利用NCEP再分析资料和实测降水数据,运用HYSPLIT轨迹模式对金华地区2018—2019年冬季连阴雨事件的水汽输送特征进行分析。模拟计算了3个月不同高度层的水汽输送通道和不同来源的水汽贡献率,并结合水汽通量场分析影响金华地区降水异常增多的原因。结果表明:2018—2019年冬季的水汽输送通道主要有四支:欧亚非大陆-北大西洋、太平洋、印度洋孟加拉湾-南海和局地水汽通道;局地水汽通道是低层的主贡献通道,中高层12月份来自孟湾和南支槽的水汽贡献较大,1月份以西太平洋和南海的水汽输送为主,2月份南海和西南急流的水汽贡献较大;2018—2019年冬季副热带高压偏西偏强和厄尔尼诺繁盛期也是这次连阴雨灾害产生的原因,但其影响强度和发展机理还需进一步探讨。

Based on the NCEP reanalysis data and measured precipitation data,the HYSPIT trajectory model was used to analyze the water vapor transport characteristics of continuous rain events in winter from 2018 to 2019 in Jinhua Area.The water vapor transport channels and contribution rates of water vapor from different sources at different altitudes in three months are simulated,and the reasons for the abnormal increase of precipitation in Jinhua Area are analyzed by combining the water vapor flux field.The results show that:There are four main water vapor transport channels in the winter of 2018-2019:Afro-Eurasia and North Atlantic channel,Pacific channel,bay of Bengal and South China Sea channel,local water vapor channel.Local water vapor channel is the main contribution channel in the lower layer.In the middle and upper layers,the water vapor from the bay of Bengal and south branch channel in December contributes more,and the water vapor transport in the West Pacific and South China Sea in January,and in February,the contribution of water vapor in the South China Sea and the Westerlies is relatively large.The strong subtropical high and the high El Nino period in winter of 2018-2019 are also the causes of this continuous rain disaster,but the impact intensity and development mechanism need to be further discussed.