GGR217H5 Lecture Notes - Lecture 3: Transect, Lake Huron, Vehicle Emissions Control
Document Summary
Consists of ice crystals air and water. Sig portion of ppt falls as snow above 45 latitudes: determines the availability of water to vegetation, amount and timing in stream flow and ground water recharge. Snow modifies energy balance of earth"s surface. Requires: presence of water vapour, saturation, temp < 0 , presence of condensation nuclei. Nucleation ice crystals snow: three ways for snow to form, vapor deposition on crystals (sublimation, water droplets adhere to crystals (riming, crystals adhere to each other (aggregation) Snowflakes are the aggregation of many ice crystals. All cool or cold clouds produce snow. Temp of the air below the cloud determines the eventual type of ppt out of the clouds. Snow cover: areal or fractional area covered by snow (m^2, fraction or %) Surface snowfall rate: amount of snow received at surface per unit area and time (kg/m^2/hour) Snow mass: amount of snow per unit area per unit depth (kg/m^2)
