Statistical Aspects of the Precipitation Regimes at Miami International Airport(MIA) and Palm Beach International Airport (PBI): 1961-1990

摘要

Low-frequency components of the time series of mean annual precipitation for 1961-1990 at Miami International Airport (MIA) and Palm Beach International Airport (PBI) are closely in phase. The data show a decadal-scale variation with relatively high precipitation in the l960's and 1980's and relatively low precipitation in the l970's. This fluctuation is concomitant with a statistically significant decadal-scale fluctuation in tropical weather system frequency. MIA precipitation is systematically related to tropical weather system frequency on monthly and seasonal time scales but not so precisely that one can conclude a cause and effect relationship exists. Spectral analysis showed well marked peaks in the MIA and PBI spectra (computed from annual precipitation totals) at a period of 15 years. Cospectral calculations indicated that the covariance of the MIA and PBI annual precipitation totals was primarily the result of fluctuations with periods of 10 years or more. The time series of annual rainfall totals at both stations, when smoothed with five-year running means, showed maxima in the decade of the 1960's. Analyses of year-month cross sections showed that these maxima were the result of anomalously high rainfall in June and September-October during the later half of that decade.