Original scientific paper
Stationarity, Trend and Periodicity of Precipitation at the Zagreb-Grič Observatory from 1862 to 1990
Marjana Gajić-Čapka
; Državni hidrometeorološki zavod, Zagreb, Hrvatska
Abstract
This paper deals with the climatic change in the annual, warm half-year and cold half-year precipitation data during the last 129 years, since the beginning of the series in 1862 to 1990, at the Zagreb-Grič Observatory (φ = 45° 49', λ = 15° 59', H = 159 m a.s.l.) located in the northwestern part of Croatia. The analysis has been deduced by using tests for normality, the "quick test" for stationarity according to Schönwiese and Malcher, weighted moving average filters, the Mann-Kendall rank statistic for trend, and the power spectrum analysis.
This analysis shows the stationarity of time series of precipitation amounts. A generally decreasing, not statistically significant trend is present over the entire time interval (1862-1990). The annual and warm half-year precipitation spectra can be fitted by Markov "red noise" continuum and the cold half-year precipitation series by that of "white noise". Quasi-periodic oscillations appear in two spectra ranges: short (2 - 6 years) and medium (16 - 43 years).
Keywords
precipitation; stationarity; trend; periodicity; power spectrum; Zagreb; Croatia
Hrčak ID:
68291
URI
Publication date:
16.12.1992.
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