Lumipeitteen

Lumipeitteen is the layer of snow that covers the ground during winter in cold climates. It forms when atmospheric precipitation falls as snow and accumulates when temperatures remain cold enough to prevent immediate melting. The extent and thickness of lumipeitteen vary with weather conditions, wind, topography, vegetation, and land use. Snow can be redistributed by wind, creating uneven coverage and drifts.

The snow cover consists of accumulated snow grains that change through metamorphism as temperature and moisture conditions evolve. Freshly fallen snow is light and loose, while older layers can become denser and crusted or develop grain types such as depth hoar. These internal changes influence properties such as porosity, density, thermal conductivity, and stability, which in turn affect soil temperature, insulation, and the potential for avalanches or ice formation at the surface.

Monitoring lumipeitteen involves measuring snow depth and the snow water equivalent (SWE), which estimates how much liquid water the snow would yield when melted. Methods include manual snow pits, automated sensors, snow pillows, and satellite or aircraft observations. Data are used for weather forecasting, hydrological planning, and climate research.

Ecological and climatic significance includes the albedo effect, where snow reflects sunlight and reduces local warming, and insulation of soil and plant roots, which influences ecosystem timing in spring. Changes in snow cover patterns are among the observable indicators of regional climate variability and change.