El Nino/La Nina事件对许昌气候的影响

Impact of El Nio /La Nia Event on Climate in Xuchang

根据1971～2009年期间发生的El Nino/La Nina事件和许昌市气象资料,利用统计分析的方法分析了1971年以来许昌气温、降水、旱涝灾害与El Nino/La Nina事件之间的关系,初步揭示了El Nino/La Nina事件对许昌气候的影响。结果表明,许昌市39年来温度和降水均有升高的趋势;厄尔尼诺年平均气温比正常年份高0.1℃,平均降水量比正常年份少34mm,厄尔尼诺次年降水增加,降水量多于正常年份35.3mm;拉尼娜年气温上升且波动较大,拉尼娜发生年平均气温比正常年份高0.3℃,拉尼娜年降水量多于正常年份2.3mm,拉尼娜次年降水量少于正常年份15.5mm;从气温来讲,拉尼娜年许昌气温的上升幅度要大于厄尔尼诺年气温的上升幅度。从降水量上来讲,厄尔尼诺年对许昌降水量的影响度要大于拉尼娜年对降水的影响度。El/La事件对许昌市旱涝灾害影响显著,拉尼娜年发生大涝灾害的几率较大。

According to the statistical data of El Nio /La Nia event in the world and the meteorological data of Xuchang city in Henan province during the years of 1971-2009,this article used statistical analysis method to analyze the relationships between El Nio /La Nia event and Xuchang temperature,rainfall,drought,flood disaster since 1971.The results showed that both the temperature and rainfall of Xuchang have been increasing since 1971.In El Nio year,the average temperature was 0.1 ℃ higher than that in the normal year,and the average rainfall was 34.0 mm less than that in the normal year.While the average rainfall in the next year of El Nio year was 35.3 mm more than that in the normal year.In La Nia year,the yearly temperature ascended and greatly fluctuated,the average temperature was 0.3 ℃ higher than that in the normal year,and the average rainfall was 2.3 mm more than that in the normal year.While the average rainfall in the next year of La Nia year was 15.5 mm less than that in the normal year.So La Nia event had greater influence on the average temperature in Xuchang than El Nio event,while the former had less effect on the average rainfall than the latter.El Nio /La Nia event had significant effects on the drought and flood disasters of Xuchang,and in La Nia year flood disaster was more likely to occur.