МЕЖГОДОВАЯ ИЗМЕНЧИВОСТЬ СЕЗОННЫХ КОЛЕБАНИЙ УРОВНЯ НА РОССИЙСКОМ ПОБЕРЕЖЬЕ БАЛТИЙСКОГО МОРЯ

Abstract

Seasonal oscillations, expressed by the annual and semi-annual components, is one of the main types of long-period sea level variability of the World Ocean. Seasonal sea level oscillations of the Baltic Sea have significant interannual variations. In this study, the features of changes in seasonal sea level oscillations in the Baltic Sea during the XX-XXI centuries were studied on the basis of long-term coastal observations. To distinguish seasonal sea level oscillations in the Baltic Sea, the present study used the seasonal correction procedure X-12- ARIMA. The results of this study have shown that the amplitude and the moment of the maximum in the seasonal sea level significantly vary from year to year. In the period from 1990 to 2005, there was a significant shift in the maximum of the annual cycle for several months from October-December to January-February, which was noted also from the data of the coast of the southeastern part of the Baltic Sea and in the Gulf of Finland. These features of annual sea level oscillations are formed under the influence of large-scale factors affecting the entire Baltic Sea, for example, changes in wind and atmospheric pressure. The series of seasonal sea level oscillations to estimate their average and maximum amplitudes during the second half of the XX-XXI centuries. The average long-term height (2o) of seasonal sea level variations in the eastern part of the Gulf of Finland is 25-27 cm. The maximum range of seasonal sea level variations in this sea area can reach 56-59 cm.