【摘要】 利用1981-2010年ERA-I再分析资料和探空资料,分析了海南岛夏半季、冬半季平均大气可降水量(PW)的年际变化趋势、时空分布特征及影响因素。结果表明:海口和三亚月平均PW年变化均存在一个单峰结构,最高值(8月)与最低值(1月)的比值均大于1.8。冬夏半季PW差异值为18.1~20.0mm,夏半季和冬半季平均PW与海拔高度存在负相关,季节和五指山地形因素对PW空间分布有重要影响;夏半季和冬半季平均PW距平曲线正负极值所在年份分别与El Nio和La Nia事件年有比较明显的对应关系;EOF分析显示,夏半季和冬半季平均PW的第1模态空间分布均呈现全区域一致性负值分布,其时间系数正负值转变均发生于2003年,即大气可降水量呈现先减少后增加的趋势。更多还原

【Abstract】 Based on ERA- I re- analysis and Radiosonde data during the years 1981- 2010,the variation trend,spatiotemporal distributions and influencing factors of precipitable water( PW) in Hainan Island were analyzed.Results show that,the annual variations of monthly average of PW present a single peak in both Haikou and Sanya.The ratio of maximum to minimum at two stations are both more than 1. 8. The difference of PW between dry- season and rainy- season is at 18. 1mm ~ 20. 0mm. There is a significant negative correlation between the two seasons’ mean PW and altitude. Season and Wuzhi Mountain terrain are important factors influencing PW spatial distributions. There is obvious corresponding relation between the years with positive( negative) extreme value of PW anomaly and El Nio( La Nia) event year. EOF analysis indicates that,the spatial distribution of the first mode of the mean PW in the two seasons all present consistent negative- value distribution in the whole region,the PC value of which exhibits a positive to negative change in 2003,that is,first increase and then decrease.更多还原