Snjólag

Snjólag is the layer of snow that covers the ground during winter in cold regions. Its thickness and duration depend on weather, topography, and climate. A snowpack can include fresh snow, settled layers, and crusts, with properties described by depth, density, and snow water equivalent.

Snow forms when atmospheric moisture falls as flakes and accumulates. Over time, compaction and metamorphism create a stratified snowpack with layers such as recent snowfall, wind slabs, and depth hoar near the ground. Density increases with aging, affecting strength, insulation, and melt behavior.

Seasonal patterns and measurements: In temperate and polar regions snjólag builds in autumn or winter and melts in spring, sometimes persisting into early summer at high elevations. Snow water equivalent measures the liquid water content. Monitoring uses ground gauges, snow pillows, and remote sensing data from radar and satellites.

Impacts: Snow cover alters surface albedo and insulates soils, influencing soil temperature and hydrology. Melt timing affects river flows and groundwater recharge, and snowpack instability can trigger avalanches. Snow also supports ecosystem habitats and affects human activities such as transportation and agriculture.

Climate context: Climate variability and change affect snjólag through altered snowfall, temperature, and melt rates. In many regions, snow cover duration decreases, while in others it may become more intermittent. Snow remains a key indicator for hydrology and climate studies.