台湾岛云量,降水量的EOF分析及其与EL Nino关系的研究

本文根据最新整理的台湾岛地面气象要素观测资料，利用ＥＯＦ方法分析了台湾总云量、低云量和降水量的年变化和年际变化特征，结果表明：季节变化中，总云量、低云量和降水量的ＥＯＦ模态一各自反映了它们的基本气候特征，即台湾岛的东北（包括台北）及东部地区全年总云量、低云量较多，除花莲以外，云量以低云为主，１２月￣５月较多，６月￣１１月较少；台湾岛的西南地区虽然全年总云量、低云量较少，但夏季云量明显增多，台湾岛的

IME AND SPATIAL DISTRIBUTION OF CLOUD AMOUNT AND PRECIPITATION IN TAIWAN ISLAND

Based on the latest surface meteorological data in Taiwan Island,the annual and inter-annual variation characteristic of total cloud amount,low-cloud amount and precipitation are a;ialyzed using EOF method. The rnain results are: 1)The total cloud amount and low-cloud amount in Taiwan distribute unevenly with time and space. 2)The largest cloud amount appears to the northeast and east part of the Island. With the exception of Hualian station, the clouds are mostly low level clouds,the seasonal variation shows that there are more clouds in winter and spring and less in surrunr and fall in this area. 3)To the southwest and west part of the Island,the annual cloud amount is smaller as compared with that in the east of the island 1but in surnxnr,the cloud amount in this region is larger, 4)The precipitation is mostly concentrated in summer.With the Central Mountain as the central boundary line,the annual oscillation period in west-east direction is clear with respect to total cloud amount,low-cloud amount as well as precipitation. The seasonal variation of cloud amount and precipitation in Taiwan can be mainly attributed to the topography and monsoon activity,the cold and /or warm ocean currencies and the relevant sea-atmosphere interaction also can play important role on it. For the inter-annual variation,the total eloud and low-cloud amount show two different types,the winter-type and surnrner-type. The possible relationship between EL Nino and the autumn precipitation in the Island is discussed as well.