中国季降水量的气候噪声和潜在可预报性估计

利用中国130个测站1961—2004年的日降水量资料,使用低频白噪声延伸法和方差分析法估计了中国季降水量的气候噪声方差和潜在可预报性。结果表明：中国季降水量的气候噪声方差由南向北、由沿海向内陆逐渐减小,且有明显的季节变化,夏季最高,其次是春秋季,冬季最小,而且内陆的季节变化比东南沿海的季节变化显著。季降水量的潜在可预报性有较大的季节和区域差异,但总体来说,全国大部分地区的季降水量是潜在可预报的。以绝对误差小于均方差0.68倍作为预测正确标准,全国大部分地区季降水量的预报正确率上限为50%-60%。

Estimate of Climatic Noise and Potential Predictability of Seasonal Precipitation in China

Based on the daily precipitation data of 130 stations selected over China from 1961 to 2004, the variance due to climatic noise and potential predictability of seasonal precipitation over China are es- timated in terms of low frequency white noise extension method and the analysis of variance. Results show that the variance due to the climatic noise of seasonal precipitation decreases gradually from south to north and from the coastal to the inland. It varies with markedly seasonal variations, with the greatest in summer and the smallest in winter, and the seasonal variation is larger in the inland than that in the inshore. Although potential predictability of seasonal precipitation is different from season to season and from area to area, the seasonal precipitation of the most areas over China can be predicted. Regarding the absolute error which is smaller than 0.68 times of standard deviation as the criterion of correct prediction, the upper limit of the prediction accuracy would be 50% to 60% in a majority of China.