基于FFT和小波变换的台风天气GNSSZTD周期特征分析

Typhoon Weather GNSS ZTD Cycle Characteristics Analysis Based on FFT and Wavelet Transform

利用中国内地构造环境监测网络GNSS观测数据,结合台风事件资料,开展台风事件对中国内地地区水汽变化周期影响研究。分析发现,在台风影响下,GNSS天顶对流层延迟(zenith tropospheric delay,ZTD)水汽变化周期与正常天气相比会缩短,同时降水增加。通过与降雨进行对比发现,台风过程中降雨发生之前ZTD会发生较为剧烈的变化,并保持在一个峰值。通过选取台风中心不同距离的GNSS站点进行对比分析发现,台风最先经过的区域站点ZTD产生波动要比之后经过的站点早,且台风先经过区域的降水量比后经过区域的降水量大。本文研究可为台风轨迹预报和气象部门的台风灾害及极端降水等预警提供参考。

Using GNSS observation data of CMONOC,combned with typhoon event data,we study the influence of typhoon events on water vapor cycle in Chinese mainland area.We find that under the influence of typhoon,the change period of GNSS ZTD will be shortened compared with normal weather,and precipitation will increase.Compared with the rainfall process,we find that before the rainfall occurs in the typhoon process,ZTD will change violently and keep at a peak value.By comparing and analyzing GNSS stations with different distances from the typhoon center,a typhoon’s first passing through the regional station fluctuates earlier than ZTD’s later passing station,and typhoon precipitation in the first area is greater than in the second area.This analysis of the periodic variation characteristics of water vapor in Chinese mainland during typhoon events,can provide reference value for typhoon track forecast,typhoon disaster warning and extreme precipitation warning of meteorological departments.