Author(s): Matti Lepparanta

Linked Author(s):

Keywords: Lake ice; ice thickness; porosity; solar radiation; climatology

Abstract:

An overview of lake ice decay is presented based on field data, modelling, and climatology. The time scale of the decay is one month for half meter thick seasonal lake ice. Field data are limited because it is dangerous to work on a weakening ice cover, and modelling efforts suffer from good validation data as well as from parameterization problems with albedo and light transmittance. Remote sensing methods suffer from the co-presence of liquid water with ice. Lake ice decay is a chaotic process where thermal, radiative, and mechanical processes drive the deterioration in intense interaction. Melting at the ice surface and bottom decrease ice thick-ness while internal melting increases the porosity and, consequently, the decreases the strength of the ice. In cli- matological analyses a common approach has been to estimate the melting using the positive degree-days of air temperature. To include properly for the role of the solar radiation, a latitude dependent term must be added to the picture. The climate sensitivity of ice decay and break-up is in the local heat balance in the maximum annul ice thickness and snow accumulation on ice.

DOI: https://doi.org/10.5281/zenodo.14507163

Year: 2024