Multi-Temporal-Scale Variation of Annual Precipitation in Zhuhai
Wen Min(Zhuhai Meteorological Bureau, Zhuhai, China 519000)
Morlet wavelet is applied to the analysis of the 40-year (1961～2000) annual precipitation and temperature data from Zhuhai. Results show that the annual precipitation has a complete quasi-22-year periodic oscillation with two low centers (1960～1970 and 1980～1990) and two high centers (1970～1980 and 1999～2000), which can benefit the long-term forecast to some extent. And there is no global trend for other relatively short period oscillations. Time series of the wavelet variance for 28, 12, and 4-year periods show that, for the 28-year period, precipitation and temperature data follow the same trend with two abrupt change points (in 1974 and 1987), while for 12 and 4 year periods, the trend of precipitation is just opposite to that of temperature.