Wpływ Oscylacji Północnoatlantyckiej na zmiany stabilności reżimu stanów wody jezior w Polsce

Abstract

The paper presents results of research on the stability of water stage regime of Polish lakes in different phases of the North Atlantic Oscillation. The stability of the regime was defined as the degree of regularity of occurrence of a particular phase of the hydrological regime, i.e. high and low water stages. The determination of the stability of water stage regime in lakes applied the stability coefficient. The analysis covered data concerning mean monthly values of water stages from 1976–2010 for 34 lakes located in Polish lakelands. According to the study, the effect of changes in the North Atlantic Oscillation on water stages in lakes is variable in time and space. In the positive NAO phase, maximums on lakes occur earlier than on average – in winter and spring, and in the negative phase - later. Minimums change in a lower range, particularly in the positive NAO phase. In the negative phase, on the majority of lakes, the term of appearance of Imin was later than on average. The term of occurrence of minimums is considerably variable, particularly in the positive phase, and in the negative phase it is usually later, and occurs in autumn.