延吉市日照与厄尔尼诺和拉尼娜事件的关系

Relation with Sunshine Duration in Yanji and El Nino/La Nina

根据延吉市延吉站1954年至2002年49年的日照时数观测资料，分析了厄尔尼诺和拉尼娜发生时延吉市日照时数的变化特征．结果表明，延吉市日照时数具有与厄尔尼诺和拉尼娜发生周期相一致的3～8年的变化周期；厄尔尼诺和拉尼娜事件均使延吉市的年日照时数增加．研究还表明，延吉市日照时数滞后赤道东太平洋Nino3区海温5个月和27～36个月时达到显著负相关，超前6个月时达到显著正相关；厄尔尼诺和拉尼娜事件发生前的5～9月农作物生长季延吉市日照时数有较明显的减少．厄尔尼诺和拉尼娜事件对延吉市日照时数的影响是通过东亚大槽的异常变化导致延吉市总云量的异常改变而造成的．

Based on the data of daily sunshine duration in Yanji from 1954 to 2002, the relationship between the sunshine duration and EL Nino and La Nina is analized by statistical methods. The result shows that the sunshine duration in Yanji has several significant inter-annual oscillation periods, namely 8-year period and 3-year period. El Nino and La Nina events make the sunshine duration increasing. The result also shows that the sunshine duration is related to the El Nino and La Nina events what is shown as a significant correlation in 5 months lag or any one of 27 to 36 months lags and in 6 months leading. The sunshine duration during 5 to 9 months has decreased before El Nino and La Nina events period. The impact of El Nino/La Nina on the sunshine duration in Yanji is caused by change of total cloud cover and the East Asia deep trough.