LOW-FREQUENCY RAINFALL CHARACTERISTICS OF THE TYPICAL FLOOD YEARS IN THE ANNUALLY FIRST RAINY SEASON OF SOUTH CHINA AND THEIR RELATIONSHIPS WITH LOW-FREQUENCY MOISTURE TRANSPORTATION
Abstract：Based on 753-stations' daily rainfall data provided by the National Meteorological Information Center and the NCEP/NCAR daily reanalysis data from 1961-2013,and HYSPLIT model synchronous driving data from NOAA,the low-frequency variability of the precipitation of nine typical flood years and its relationships with moisture transport in the annually first rain season (AFRS) of South China is investigated,and the source regions and transportation paths of low-frequency water vapor are discussed.The results show that the precipitation of the nine typical flood years is mainly controlled by 10 ～20 d oscillation in the AFRS,and 30～60 d low frequency oscillation is also significant in the area connecting Jiangxi with Fujian.Both the longitudinal and zonal water vapor flux have remarkable 10～20 d low frequency oscillation in the AFRS.There are four 10～20 d water vapor reference sources and transportation paths which affect the 10～20d low frequency precipitation of the nine flood years in the AFRS.These sources lie in the part of the Indian Ocean north of Madagascar Island and equatorial middle India Ocean(the southeast moisture transport channel),the ocean to the southeast of Japanese archipelago and the equatorial middle Pacific (the southeast moisture transport channel),north of the Caspian Sea and southeast of Lake Baikal (the northwest cold air channel),and Bering Sea (the northeast cold moisture transport channel).The above four water vapor transportation paths are verified by the backward trajectory simulations of water vapor in typical flood years of the AFRS at Fogang and Guangchang stations respectively,and the simulation sources all lie in the key areas of the moisture transport channels.Both the reference and simulation sources can be taken as important areas to make extended-period(2～6 days ahead)prediction.
Keywords：annually first rain season of South Chinatypical flood yearslow frequency oscillationwater vapor transport path and source
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：14( 299-312 )