利用GPS Dropsonde资料研究“龙王”台风的结构特征

"龙王"台风是2005年登陆中国的典型强台风。在海上观测资料较为稀缺的情况下,应用DOTSTAR(Dropsonde Observations for Typhoon Surveillance near the Taiwan Region)对"龙王"不同发展时段的两次GPS Dropsonde观测资料,对其动力、热力及非对称结构的变化情况进行分析。结果表明,第二次观测到的"龙王"无论在动力结构还是在热力结构上都较第一次观测有所发展,显示"龙王"强度压缩增强。进一步研究表明,环境垂直风切变是造成台风结构不对称分布的主要原因,较大的垂直风切变不但导致台风产生明显的非对称性结构,而且不利于台风的进一步增强。

ANALYSIS ON STRUCTURE OF TYPHOON LONGWANG BASED ON GPS DROPSONDE DATA

As one of the most severe typhoons making landfall in China in the year 2005, Longwang is chosen here for case study. Being different from previous studies, global positioning system(GPS) Dropsonde data collected during the Dropwindsonde Observations for Typhoon Surveillance near the Taiwan Region (DOTSTAR) were chosen to study the thermal and dynamic structure for its two typical periods of life. Two surveillance flights were carried out throughout its lifetime. The result shows that both dynamic and thermal structures of Longwang are more robust in the second observation than in the first, which are manifested by stronger and larger circulation and the presence of a warm core. Further research shows that the environmental vertical wind shear mainly contributes to the asymmetric structure of the typhoon. Large vertical wind shear not only results in a significantly asymmetric structure, but also restrains the development of the typhoon.