Estimation of tendencies, homogeneity and stationarity of air temperature at the Ukrainian Antarctic Akademik Vernadsky station during 1951—2020

Abstract

In this paper results of the complex analysis of surface air temperature tendencies investigations at the Ukrainian Antarctic Akademik Vernadsky station are represented. Antarctica is a region that has a high rate of surface air temperature increase. The Antarctic Peninsula has experienced particularly fast warming, which has the highest temperature rise in the Southern Hemisphere. Therefore, in Antarctica, the study of surface air temperature change is important. The Ukrainian Antarctic Akademik Vernadsky station is located on Galindez Island near the Antarctic Peninsula. Investigation of the surface air temperature is especially relevant to the Akademik Vernadsky station, because it has difficult conditions for its formation. The research goal is the estimation of tendencies, homogeneity and stationarity of the annual and mean monthly values of surface air temperature at the Ukrainian Antarctic Akademik Vernadsky station based on a combined approach with the use of several statistical and graphical methods. The use of various statistical methods that differ in characteristics (sensitivity to the law of distribution, autocorrelation, etc.) allows obtaining more reliable estimates. Graphic methods give an opportunity to analyze the tendencies over time and its change periods, the cyclical fluctuations and their characteristics (phases of increase and decrease, their duration, synchronicity, in-phase). Therefore, 4 statistical tests (standard normal Alexandersson test, Buishand test, Pettitt test, von Neumann relation) and 2 graphical methods (mass curve and residual mass curve) were used in the study. At the Ukrainian Antarctic Akademik Vernadsky station, the observation series of the mean annual air temperature are quasi-homogeneous and quasi-stationary, as it has only a cooling phase and a warming phase of long-term cyclical fluctuations, which are also unfinished. The transition from the cooling phase to the warming phase took place in 1982. Tendencies in mean monthly air temperatures are similar to tendencies in mean annual temperatures. The differences are only for some months, namely, for the period from September to December.