西太平洋副热带高压耦合模态对台风生成的影响

西太平洋副热带高压(西太副高)是影响东亚夏季气候的主要环流系统。利用再分析资料和美国联合台风预警中心的热带气旋最佳路径资料,研究了西太副高耦合模态对西北太平洋7—9月的台风生成的影响。结果表明:西太副高耦合模态与西太平洋地区的台风生成有显著抑制作用,且主要发生在西北太平洋北部;当西太副高偏强(弱)时,西北太平洋地区的台风生成频数偏少(多)。进一步研究表明西太副高耦合模态可以通过调节影响台风生成的850hPa涡度、垂直速度、600hPa相对湿度、垂直风切变等关键大尺度环境参数进而影响台风活动。

Effects of coupling mode of the Western Pacific Subtropical High on typhoon generation

The Western Pacific Subtropical High is the main circulation system that affects the summer climate in East Asia.Based on the reanalysis data and the best track data of tropical cyclones from Joint Typhoon Warning Center of the United States,this paper studied the influence of the coupling mode of the West Pacific Subtropical High on the typhoon generation in the Northwest Pacific from July to September.The results showed that the coupling mode of the West Pacific Subtropical High had a significant inhibitory effect on typhoon generation in the Western Pacific,mainly in the northern part of the Northwest Pacific.When the West Pacific Subtropical High was strong(weak),the typhoon frequency in the Northwest Pacific was less(more).Further research showed that the coupling mode of the West Pacific Subtropical High could affect typhoon activity by adjusting the key large-scale environmental parameters such as 850 hPa vorticity,vertical velocity,600 hPa relative humidity,and vertical wind shear.