淮河流域致洪暴雨的异常水汽输送

为了从多方面提取对致洪暴雨有指示意义的异常信息,进一步提高对致洪暴雨的判别能力,利用Box-Cox变换将信号场方法引入致洪暴雨水汽条件气候异常的诊断,并具体分析了2003年、2005年和2007年淮河流域致洪暴雨850 hPa水汽通量场的气候异常特征。结果表明:淮河流域致洪暴雨期间,850 hPa经向水汽通量信号场105°E~125°E易形成以淮河流域为中心南正北负的双极型配置;850 hPa纬向水汽通量信号场低纬的显著信号反映出各条水汽输送通道的相对重要性因致洪暴雨而异。

Water vapor transport anomalies of flood-causing rainstorms in Huaihe River basin

A signal-based anomaly detection method with the Box-Cox transformation technique are adopted in an effort to effectively extract anomalous information from multiple data sources, and to improve the identification of water vapor transport anomalies of flood-causing storms (FCSs). The combined approach is applied to the Huaihe River Basin (HRB) to studying the anomalous characteristics of 850 hPa water vapor flux for the years of 2003, 2005 and 2007. The results show that during FCS periods, the 850 hPa meridional flux of water vapor between longitude 105° E and longitude 125° E is likely to form a dipole pattern with the HRB as its center and the positive anomaly on the south and the negative on the north. The importance of water vapor transport channels varies with FCSs as revealed by the 850 hPa zonal transport anomalies of water vapor at lower latitudes.