江淮梅雨期降水不同尺度异常与SSTA的关系

Relationships between Different Multi-time Scales of Anomalous Precipitation in Jiang-Huai Mei-yu and SSTA

利用1959—2000年江淮地区80站的月降水量资料,研究江淮梅雨期(6—7月)不同尺度降水量异常的时间演变规律,分析江淮梅雨不同尺度降水异常与海温异常的关系。结果表明:1)近42 a来,江淮梅雨期降水异常呈明显上升趋势,同时存在显著的年际、年代际尺度变化信号。2)对江淮梅雨期降水异常进行时间尺度分离,不同尺度的降水异常序列多(少)雨年份表现出很大的不同。在少雨背景上,年代际变化序列出现多雨期。在多雨背景上,年际变化序列出现明显的少雨年份。3)分析不同时间尺度的江淮梅雨期降水异常序列与SSTA的关系,发现对应的显著相关区域有很大不同,这意味着海温异常对江淮梅雨存在多时空尺度的影响作用。

By using of the 42 a （1959-2000） monthly precipitation data at 80 sites in the ChangjiangHuaihe River valley, the temporal characteristics of Mei-yu precipitation anomalies and its related SSTA as well as its possible mechanism are investigated. It is found that the anomalies of Mei-yu precipitation in the Changjiang-Huaihe River valley exhibit an up-trend unusually, having significant interannual and interdecadal change characteristics. By filter analysis, the relationship between anomalous precipitation of different time scales and the corresponding anomaly of SST is analyed. It is found that SSTA exerts a multi-time scale infuence on Jiang-Huai Mei-yu and its precipitation anomalies as well.