华南前汛期起讫日期的年际变化及与前汛期降水的关系

根据国家气候中心最新颁布的华南前汛期业务监测标准,采用小波分析、合成分析、相关分析等统计方法研究了1961~2014年华南前汛期入汛日期、出汛日期、持续时间及前汛期累计降水量异常的变异特征。结果表明：华南前汛期入汛日期的年际变化特征主要表现为7~8 a及准2 a周期,年代际变化特征主要表现为20世纪60至70年代入汛偏晚,80年代入汛偏早;华南前汛期出汛日期的年际变化特征主要表现为6~7 a周期,年代际变化特征表现为20世纪60年代中期前出汛偏早,70年代中期以来出汛偏早。华南前汛期入汛早晚对其持续时间及累计降水量有很好的指示意义,表现为入汛越早,华南前汛期持续时间偏长的可能性越大,对应前汛期累计降水量偏多。

Inter Annual Variation of the Onset and Ending Dates of the First Rainy Season in South China and Their Relationships with the Corresponding Precipitation

Using the latest monitoring standard of the first rainy season in South China issued by National Climate Center, the characteristics of the onset date (ODFRS), the ending date(EDFRS), the duration and the precipitation of the first rainy season in South China were analyzed by utilizing the wavelet transform method and the composite as well ascorrelative analysisstatistical methods. The results showed that there were 7-8 years and quasi-2 years oscillation cycles of the ODFRS. The decadal variation indicates the ODFRS were later than normal from the 1960s to 1970s while they were earlier in the 1980s. The EDFRS has 6-7 years oscillation cycles, and they were in the earlier during the middle of 1960s, but gradually advanced after the middle of 1970s. The ODFRS in South China has indicative function to the duration time and the precipitation of the first rainy season in South China. The earlier the ODFRS comes, the more likely that the first rainy season will be longer. Correspondingly, the precipitation will be above normal.