Interannual Variations and Causes of the Pre-flood Season Onset Date in Fujian during 1961 to 2023
According to the South China flood monitoring operation regulations,the interannual variation characteristics of the pre-flood season onset date in Fujian over the past 63 years were analyzed using statistical methods such as correlation analysis,wavelet analysis,and composite analysis.The relationship between the pre-flood season onset date and precipitation in various regions of Fujian was studied,and the anomalies in the pre-flood season onset date in Fujian were discussed in relation to sea surface temperatures in early winter and atmospheric circulation in early spring(March-April).The results showed that the interannual variation characteristics of the pre-flood season onset date in Fujian were significant,with a main oscillation period of 25 years.The earliest onset occurred on April 2 in 1973 and 1979,while the latest onset occurred on June 1 in 1963.The av-erage onset date of the pre-flood season in Fujian from 1961 to 2023 was April 27.The onset date of the pre-flood season in Fu-jian was well correlated with the spring precipitation in most parts of Fujian,the March precipitation in the central coastal are-as,and the April precipitation across the province.In years with early pre-flood season onsets,the sea surface temperature in the central northwest Pacific in the preceding winter was lower,while the sea surface temperature in the eastern tropical Pacific was higher.Additionally,in early spring,the subtropical westerly jet stream was stronger,the subtropical high was stronger and westward-shifted,and the southwest airflow over the South China Sea to Fujian was stronger.Conversely,in years with delayed pre-flood season onsets,the opposite conditions prevailed.
pre-flood season onsetinterannual variationatmospheric circulationsea surface temperature
万方数据
