基于海洋温度分布模态最优组合的中国东部夏季降水预测研究

Summer Precipitation Prediction in Eastern China Based on Optimal Combination of Ocean Temperature Distribution Modes

通过EOF-CCA方法,以热带太平洋5月海洋表面温度为预测因子,对中国东部夏季降水进行预测研究.首先,通过热带太平洋5月海洋表面温度与中国东部夏季降水的前15个EOF模态进行CCA分析,对不同个数CCA模态,对建立的预测模型进行交叉检验.然后,通过交叉检验的技巧评分对所建预测模型进行评估.结果表明,5月热带太平洋表面温度与中国东部夏季降水有密切的联系,前7个CCA模态比15个CCA模态建立的中国东部夏季降水预测模型的预测效果好,且前7个CCA模态建立的降水预测模型对长江流域的预测效果较好,1966—2015年长江流域区域夏季平均降水的预测值与观测值的相关系数为0.41.

Through the EOF-CCA method,the tropical Pacific Ocean surface temperature in May is used as a predictor to predict summer precipitation in eastern China.Firstly,it performs CCA analysis on the first 15 EOF modes of the tropical Pacific Ocean surface temperature in May and summer precipitation in eastern China,and cross-checks the prediction models built with different numbers of CCA modalities.Then,it evaluates the built predictive model based on technique scoring for cross-checking.The results show that the sea surface temperature of the tropical Pacific is closely connected to the summer precipitation in eastern China in May,the first 7 CCA modes are better than the 15 CCA modes for the prediction of summer precipitation in eastern China,the prediction results of the first seven CCA modes are better for the Yangtze River Basin,and the correlation coefficient between the predicted values and observed values of the average summer rainfall in the Yangtze River Basin from 1966 to 2015 is 0.41.