不同季节海温与中国夏季降水的时空特征分析

ANALYSES OF SPATIAL-TEMPORAL CHARACTERISTICS FOR VARIOUS SEASONAL SEA SURFACE TEMPERATURE VERSUS SUMMER RAINFALL IN CHINA

利用季降水异常的典型集合相关降水模式,分析了不同时段和不同区域的海温场与我国夏季(6～8月)降水之间的时空分布特征。结果表明:各大洋区海温存在着明显的季节、年际和年代际变化。与中国夏季降水相联系的印度洋海温的分布特征与季节有关,存在明显的偶极和单极分布形式,这种海温的异常变化对我国夏季纬向或经向雨带有一定的影响,全球特定的海温分布可以作为中国夏季旱涝预报的信号因子。不同季节海温和中国夏季降水在1970年代末都经历了一次突变,说明海温的季节差异对中国夏季降水的影响明显地受到海洋年代际基本态的制约。

Based on the canonical ensemble correlation prediction （CECP） model for seasonal precipitation anomaly, spatial-temporal characteristics for sea surface temperature anomalies （SSTA） versus summer （JJA） precipitation in China are analyzed, using SSTA for various seasons and different regions as predictor fields. The results show that the SSTA has significant seasonal, annual and inter-decadal changes. The distribution of Indian Ocean SST associated with summer rainfall of China, mainly being dipole and unipole, are different with seasonal changes. They have most important roles in the zonal or meridional rainbelts of China. Specific global SSTA distribution modes might be used as predictors of summer precipitation in China. Furthermore, both the various seasonal SSTA and summer precipitation in China have experienced an abrupt change after the late 1970s, indicating that the impacts of the seasonal differences of SSTA on summer precipitation in China are significantly controlled by the basic state of inter-decadal oceanic changes.