海南岛夏季降水的时空演变特征

Space-Time Characteristics of Hainan Island’s Precipitation in Summer

摘要: 利用1970~2013年6~8月份海南岛18个气象观测站月降水资料，通过EOF、REOF、Morlet小波分析方法研究了海南岛夏季降水的时空演变特征，结果表明：海南岛夏季降水的EOF分析前3个特征向量场较好地反映了降水异常的空间分布，分别为整体一致、东南与西北相反、中、西部与北、东部相反的空间结构。经REOF分析可以将海南岛夏季降水的空间结构划分为4个区域：I区为北部和东北部地区、II区为南部和东南部地区、III区为中部和西北部地区、IV区为西部和西南部地区，通过小波分析得出，I区典型代表站海口观测站夏季降水的特征时间尺度是2年、5年、11~12年，而且在11~12时间尺度上降水将开始逐渐增加，II区典型代表站保亭观测站夏季降水的特征时间尺度是6年、15~16年，而且在15~16年时间尺度上仍然处于降水偏少期，Ⅲ区典型代表站琼中观测站夏季降水的特征时间尺度是3年、7年、12年，而且在12年时间尺度上仍然处于降水偏少期，Ⅳ区典型代表站东方观测站夏季降水的特征时间尺度是4年、8年、18年。

Abstract: With the help of EOF, REOF, and Morlet wavelet analysis, the space-time characteristics of Hainan Island’s summer precipitation are studied by using June-August precipitation data during the period 1970-2013 from 18 observational stations. Results show that: the first three EOFs for summer precipitation in Hainan Island are enough to explain the spatial distribution of precipitation anomaly. The spatial structure is respectively as the same as the whole, in contrast to the southeast and northwest; the middle and the west are opposite to the north and the east. According to REOF analysis, the study region should be divided into 4 subregions, namely: Subregion I is the north and northeast area; Subregion II is the south and the southeast area; Subregion III is the northwest and the central area; Subregion IV is the southwest and the west area. According to the result of Morlet wavelet analysis, for the typical station (e.g. Haikou) in Subregion I, there are 2-year, 5-year and 11 - 12-year periods and the precipitation is gradually increasing at the 11 - 12-year timescale; for the typical station (e.g. Baoting) in Subregion II, there are 6-year and 15 - 16-year periods and the precipitation is small yet at 15 - 16-year period; for the typical station (e.g. Qiongzhong ) in Subregion III, there are 3-year, 7-year and 12-year periods, and the precipitation is small at 12-year period; for the typical station (e.g. Dongfang) in Subregion IV, there are 4-year, 8-year and 18-year periods.