ENSO事件对东莞气候特征的影响

Effect of ENSO Events on the Climatological Characteristics of Dongguan

利用1963—2021年东莞国家气象观测站的气象观测资料,运用数理统计、趋势分析和Mann-Kendall突变检测等方法从台风、降水和气温等角度进行分析,研究厄尔尼诺和拉尼娜事件对东莞气候特征的影响,分析表明:(1)2000年以前发生厄尔尼诺事件概率更大,2000年以后ENSO事件持续时间变短,厄尔尼诺和拉尼娜事件发生概率基本相当;(2)厄尔尼诺(或拉尼娜)年影响东莞的台风频数减少(或增多);拉尼娜年台风季偏长,初台偏早、终台偏晚;(3)厄尔尼诺事件发生当年东莞非汛期和次年汛期降水偏多,当年汛期和次年非汛期降水偏少;拉尼娜事件发生当年汛期和非汛期降水都偏少;厄尔尼诺和拉尼娜事件都对后汛期降水影响更明显,ENSO事件强度越强,对降水影响越大;(4)东莞气温受ENSO事件影响较小,厄尔尼诺年东莞气温偏高,拉尼娜年东莞气温偏低;高低温日数受ENSO事件影响较小,有明显的年代变化特征。

Using the meteorological observations from a national station in Dongguan from 1963 to 2021 and with the methods of mathematical statistics,tendency analysis and Mann⁃Kendall abruptness test,this paper studied from the aspect of typhoon,precipitation and air temperature,the effect of El Niño and La Niña episodes on the climatological characteristics of the city.The study has the following findings.(1)The probability for the El Niño episode to happen was larger before 2000 than after it.In addition,it lasted for shorter duration and had comparable occurrence probabilities with the La Niña episode after 2000.(2)For the El Niño(La Niña)year,there were decreased(increased)frequencies for typhoons to affect Dongguan,and the typhoon season was longer in the La Niña year,with earlier⁃than⁃usual dates of the annually first ty⁃phoon effect but later⁃than⁃usual dates of the annually last typhoon effect.(3)For Dongguan,in the non⁃rainy season of the El Niño year and the rainy season of the following year there was more precipitation,and in the rainy season of the El Niño year and the non⁃rainy season of the following year there was less precipita⁃tion,and in the year when the La Niña episode took place,there was less precipitation in both the rainy and non⁃rainy seasons.Both the El Niño and La Niña episodes affected the rainfall more significantly in the July⁃September rainy season;the stronger the ENSO event,the greater its effect on the precipitation.(4)The air temperature of Dongguan was little affected by the ENSO event,with relatively high temperature in the El Niño year and relatively low temperature in the La Niña year.The ENSO event also exerted little effect on the numbers of high⁃and low⁃temperature days in Dongguan,which varied much on the decadal scale.