Effect of teleconnection patterns on ice conditions in lakes in lowland Poland

Ice conditions in lakes are one of the basic factors considerably affecting the functioning of lake ecosystems, and the term of ice end modifies the course of further processes (thermal stratification, biological conditions, etc.) occurring outside the winter season. The paper presents the analysis of the effect of teleconnection patterns (NAO, SCAND, EA, EAWR) on ice conditions in lakes in North Poland, determining the relations between the teleconnection conditions in the cold half-year and selected features of the ice regime, i.e. dates of ice start and ice end, ice duration, and maximum ice thickness. Deviations of values of the aforementioned parameters in positive and negative phases of the considered teleconnection patterns were calculated in reference to mean values from the years 1956–2014. Two of them were determined to have considerable effect on the parameters of the ice regime, namely NAO, modifying ice start and ice end, ice duration, and maximum ice thickness in the season, and SCAND, considerably changing ice end, ice duration, and maximum ice thickness. The EA teleconnection pattern only affects ice end, and EAWR shows no correlations with the analysed ice parameters in lakes.