Long-term trends in water level fluctuations in lowland lakes in central Europe (Northern Poland).

Water level fluctuations in lakes are one of the key parameters affecting their functioning and other environmental elements present in their vicinity. They also provide information about the entirety of processes occurring in the catchment area, both natural and anthropogenic, the result of which is the filling of the lake basin with water. This study analyses changes in water levels of 25 lakes in Poland based on maximum, average, and minimum annual values from the period 1963-2022.

Occurrence and synoptic background of strong and very strong frost in spring and autumn in Central Europe.

The objective of the paper was the determination of the circulation conditions of occurrence of strong and very strong frost in Central Europe. A frost day was defined as a day with the minimum temperature lower than 0 °C and maximum temperature higher than 0 °C. Moreover, a division of frost was performed in terms of value of minimum temperature, resulting in the designation of mild frost (up to - 2.