Geographic variation and temporal trends in ice phenology in Norwegian lakes over a century
L’Abée-Lund, Jan Henning; Vøllestad, Leif Asbjørn; Brittain, John Edward; Kvambekk, Ånund Sigurd; Solvang, Tord
Abstract
Observations from 1890 to 2020 of ice phenology for 101 Norwegian lakes were used to detect variation in ice phenology. The average date of ice break-up occurred later in spring with increasing altitude, latitude and longitude. The average date of freeze-up and the length of the ice-free period decreased with altitude and longitude. Lakes were completely frozen later recently later in autumn. A significant trend for earlier break-up, later freeze-up and completely frozen lakes after 1991.