1961-2017年青海高原雨季和降水的变化特征  

Variation Characteristics of Rainy Season and Precipitation on the Qinghai Plateau from 1961 to 2017

作　　者：李红梅[1] 申红艳[1] 汪青春[1] 马有绚 LI Hongmei;SHEN Hongyan;WANG Qingchun;MAYouxuan(Qinghai climate center,Xining 810001,Qinghai,China)

机构地区：[1]青海省气候中心,青海西宁810001

出　　处：《高原气象》2021年第5期1038-1047,共10页Plateau Meteorology

基　　金：青海省科技厅基础研究项目(2019-ZJ-7060);中国科学院寒旱区陆面过程与气候变化开放基金项目(LPCC2019009)。

摘　　要：基于青海高原46个气象观测站1961-2017年逐日降水观测资料,采用REOF方法将整个高原分为3个区域,分析不同区域雨季起讫期、降水量的分布态和变化特征。结果表明:(1)自高原东南部向西北部雨季开始期逐渐推迟、结束期逐渐提前、持续期逐渐缩短、降水量逐渐减少;(2)在高原西北部和南部地区经度变化对雨季影响明显,经度每增加1°,雨季开始期分别提前2.4 d和2.0 d;结束期分别推迟2.3 d和1.2 d;持续期分别延长4.6 d和3.2 d。(3)海拔对整个高原的雨季降水量影响很大,在海拔相对较低的高原西北部和东部地区,每上升100 m,降水量分别增加46.8 mm和8.3 mm,而在平均海拔4000 m以上的高原南部地区,每上升100 m,降水量减少20.3 mm。(4)1961-2017年高原平均雨季开始期平均每10年提前1.4 d,结束期推迟0.8 d,持续期延长2.2 d,降水量增加6.5 mm。(5)高原雨季降水极端性增强,尤其是2007年以来表现明显,2007年前后中雨日数、1日最大降水量、强降水量和降水强度分别增加1.0 d、9.3%、16.9%和0.4 mm·m^(-1)。Based on the daily precipitation data from 46 meteorological stations in the Qinghai Plateau from 1961 to 2017,the whole plateau was divided into three regions using the REOF method.The variable characteristics of the beginning and ending of the rainy season,and the precipitation in different regions were analyzed.The results shows:(1)From the southeast to the northwest in the plateau,the rainy season beginning delays,the rainy season ending advances,the duration period of the rainy season is short and the precipitation decrease gradually;(2)The change in longitude had a significant impact on the rainy season in the northwest and south of the plateau.For each increase of 1°,the rainy season beginning advanced 2.4 d and 2.0 d;the end was delayed 2.3 d and 1.2 d;and the duration period was extended 4.6 d and 3.2 d,respectively;(3)Altitude has a great influence on the precipitation across the plateau.In the northwest and east area of the plateau where the altitude is relatively low,with an increase of 46.8 mm and 8.3 mm for every 100 m rise,while in the southern area of the plateau where the average altitude is above 4000 m,and a diminish of 20.3 mm for every 100 m rise;(4)The mean rainy season beginning was advanced by 1.4 d,the end period was delayed by 0.8 d,the duration was extended by 2.2 d,and the precipitation increased by 6.5 mm respectively per 10 years from 1961 to 2017.(5)The extreme precipitation during the rainy season in the plateau has Intensified significantly,especially since 2007.Comparison of the mean value from 1961 to 2017 with the mean value from 1985 to 200,the days of moderate rain,maximum precipitation within 1 day,heavy precipitation and precipitation intensity increased by 1.0 d,9.3%,16.9%and 0.4 mm·m^(-1),respectively.

关 键 词：青海高原 雨季开始期 雨季结束期 雨季降水量 空间分布 

分 类 号：P467[天文地球—大气科学及气象学]