我国秋季相对湿度变化特征分析

Analysis on Change Characteristic of Autumn Relative Humidity in China

利用NCEP相对湿度资料及EOF分解法对我国秋季相对湿度进行分析。结果表明,4个模态的方差贡献率分别为30.3%、11.8%、6.8%、5.9%。第一模态全国相对湿度偏低,东部地区尤为明显,且发生一次由湿度大转为湿度小的突变。第二模态自西向东呈"-+-+"的空间分布,1971年和1994年发生2次突变。第三模态自西南向东北呈"+-+"的空间分布,相对湿度变化以多波动形式展现。第四模态与第三模态完全相反,呈"-+-"的空间分布特征。

Based on NCEP data from 1956 to 2015 and EOF analysis,the temporal and spatial distribution characteristics of autumn relative humidity in China were analyzed. Results indicated that there were four typical spatial distributions and the variance contribution rate of the first four modes were 30.3%, 11.8% ,6.8% ,5.9% ,respectively. In the first mode ,the relative humidity of the whole country was low, especially in the eastern region,whieh had a sudden change from high to low.In the second mode,the spatial distribution of relative humidity showed ＂- ＋ - ＋＂from west to east and there were two sudden changes of relative humidity happened in 1971 and 1994.The third mode showed that the relative humidity from southwest to northeast was＂＋ - ＋＂and the fourth mode showed inverse pattern.