Snow studies
SNOW PROTOCOLS
Snow cover is important to global systems because it influences climate, hydrology, ecological processes, and human activities. Snow cover changes the energy transfer between the ground and atmosphere. Snow cover also is the frozen storage of water that affects soil moisture, runoff and stream flow. As an insulating layer snow provides cold weather habitat for a diversity of life. Humans shovel snow, use it, try to move in it and play in it.
Snow cover is a critical component of the climate system (Robinson, 1987), interacting with the atmosphere over a range of time- and space-scales. Although the major changes in spatial extent of snow cover occurs on the seasonal scale, a single weather event can extend continental snow lines equatorwards by up to 1000 km (Cohen & Rind, 1991). Snow cover influences the thermal stability of the air immediately above it, but it also interacts on the synoptic, regional or hemispheric scales.
Snow cover is a radiative sink. Its high short-wave albedo is combined with a high thermal emissivity which increases the amount of infrared radiation lost near the Earth's surface. The radiative losses are not replaced quickly by heat fluxes from below because of the thermal insulating properties of the snow. It is a particularly good insulator at night when radiative exchange is concentrated in the surface layers of the snow. The temperature of the snow surface may drop by > 10°C overnight, but the soil surface underlying snow cover as thin as 10 cm may drop by < 1 °C. When the melt occurs, the snow cover is a sink for latent heat because of the large amounts of energy required to change water phase. The surface energy balance is, thus, very strongly influenced by changing distributions of snow cover. Surface exchange processes are further modified by the small aerodynamic surface roughness of snow cover (typically 0.5 to 10.0 x 10-4 m) which reduces turbulence and vertical transfer. (Davies 1993)
(Davies 1993) In northern climates, snow generally begins to fall and accumulate during the late fall and early winter and melt during the late winter and spring. There is considerable variation in the amount of snow that falls, accumulates, the periods of accumulation and ablation (melting), the amount of water equivalence in the snow and the amount of snow that sublimes (evaporates directly from the crystal form into vapour). The layer of accumulated snow behaves in a number of ways which affects climate. Snow reflects more sunlight than soils and snow acts as an insulator which keeps the soil from cooling. Snow acts as a water source that is released in the spring.
Studies of the snow pack provide information about snow’s insulating qualities, the water that is stored in the snow pack, the changes that occur within the snow pack over a period of time, how the snow pack provides a special habitat of a variety of plants and animals, and the stability (how likely it is to avalanche) of the snow pack.
PURPOSE
The field observations are designed to provide information that relates to climatology, hydrology and our use of snow. These observations examine properties such as date of snowfall, snow accumulation and depth, layers of snow, temperature changes in the snow profile, crystal size and shape for different layers, density and water equivalent of the snow pack, and hardness of layers.
Snow Temperature Variation: Snow insulates the ground and moderates the temperature changes between the air and the ground. Temperature measurements should be taken as soon as the snow pit has been dug. The thermometer should be carefully inserted to its full extent into the snow. Be careful, thermometers will break very easily! Sufficient time should be allowed for the thermometer to equilibrate (approx. 3 minutes). Temperatures are taken at five regular intervals between the ground and the snow surface. Also record the air temperature in the shade. Record and plot these snow temperatures on the data chart.
LINKS
Canadian Avalanche Association
Catch Some Snowflakes
black velvet or black construction paper
Magnifying Glass
Since snowflakes melt so quickly you need to freeze your cloth or paper. Have it ready frozen and ready to go for the next snowfall, and go outside and let some snowflakes land on the dark surface. Quickly, before they melt, examine the flakes with a magnifying glass. Many snowflakes are "broken" and so you don't see the whole six-sided crystal, but with persistence you'll see some beautiful examples. Keep Some Snowflakes
Piece of glass Hairspray You can have a permanent record of your caught snowflakes if you freeze a piece of glass and the hairspray before the next snowfall. (Both may be stored in the freezer until you need them.) When your ready to collect some snowflakes, spray your chilled glass with the chilled hairspray and go outside and let some snowflakes settle on the glass. When you have enough flakes bring the glass indoors and allow it to thaw at room temperature for about 15 min. Now you have a permanent record of your snowflakes!
Snow pit analysis, profile stability, subniven habitats, hydrology
rates for sublimation, evapotransportation
water - snow storage, atmospheric uptake
insects under snow, insect traps, winter activity
microtines under snow, mouse tracks at snow base
quinzie and igloo construction, stability and insulating qualities
development of snow pit charts, snow depth measures
track and track casts in snow
Caribou behaviour in different snow depths
Mt Sima keep snow in cold climates, destructive metamorphism
effects on ground temp. packing snow
permafrost active layer studies, ground temp variation
SNOW PROTOCOLS
Snow cover is important to global systems because it influences climate, hydrology, ecological processes, and human activities. Snow cover changes the energy transfer between the ground and atmosphere. Snow cover also is the frozen storage of water that affects soil moisture, runoff and stream flow. As an insulating layer snow provides cold weather habitat for a diversity of life. Humans shovel snow, use it, try to move in it and play in it.
Snow cover is a critical component of the climate system (Robinson, 1987), interacting with the atmosphere over a range of time- and space-scales. Although the major changes in spatial extent of snow cover occurs on the seasonal scale, a single weather event can extend continental snow lines equatorwards by up to 1000 km (Cohen & Rind, 1991). Snow cover influences the thermal stability of the air immediately above it, but it also interacts on the synoptic, regional or hemispheric scales.
Snow cover is a radiative sink. Its high short-wave albedo is combined with a high thermal emissivity which increases the amount of infrared radiation lost near the Earth's surface. The radiative losses are not replaced quickly by heat fluxes from below because of the thermal insulating properties of the snow. It is a particularly good insulator at night when radiative exchange is concentrated in the surface layers of the snow. The temperature of the snow surface may drop by > 10°C overnight, but the soil surface underlying snow cover as thin as 10 cm may drop by < 1 °C. When the melt occurs, the snow cover is a sink for latent heat because of the large amounts of energy required to change water phase. The surface energy balance is, thus, very strongly influenced by changing distributions of snow cover. Surface exchange processes are further modified by the small aerodynamic surface roughness of snow cover (typically 0.5 to 10.0 x 10-4 m) which reduces turbulence and vertical transfer. (Davies 1993)
(Davies 1993) In northern climates, snow generally begins to fall and accumulate during the late fall and early winter and melt during the late winter and spring. There is considerable variation in the amount of snow that falls, accumulates, the periods of accumulation and ablation (melting), the amount of water equivalence in the snow and the amount of snow that sublimes (evaporates directly from the crystal form into vapour). The layer of accumulated snow behaves in a number of ways which affects climate. Snow reflects more sunlight than soils and snow acts as an insulator which keeps the soil from cooling. Snow acts as a water source that is released in the spring.
Studies of the snow pack provide information about snow’s insulating qualities, the water that is stored in the snow pack, the changes that occur within the snow pack over a period of time, how the snow pack provides a special habitat of a variety of plants and animals, and the stability (how likely it is to avalanche) of the snow pack.
PURPOSE
The field observations are designed to provide information that relates to climatology, hydrology and our use of snow. These observations examine properties such as date of snowfall, snow accumulation and depth, layers of snow, temperature changes in the snow profile, crystal size and shape for different layers, density and water equivalent of the snow pack, and hardness of layers.
Snow Temperature Variation: Snow insulates the ground and moderates the temperature changes between the air and the ground. Temperature measurements should be taken as soon as the snow pit has been dug. The thermometer should be carefully inserted to its full extent into the snow. Be careful, thermometers will break very easily! Sufficient time should be allowed for the thermometer to equilibrate (approx. 3 minutes). Temperatures are taken at five regular intervals between the ground and the snow surface. Also record the air temperature in the shade. Record and plot these snow temperatures on the data chart.
LINKS
Canadian Avalanche Association
Catch Some Snowflakes
black velvet or black construction paper
Magnifying Glass
Since snowflakes melt so quickly you need to freeze your cloth or paper. Have it ready frozen and ready to go for the next snowfall, and go outside and let some snowflakes land on the dark surface. Quickly, before they melt, examine the flakes with a magnifying glass. Many snowflakes are "broken" and so you don't see the whole six-sided crystal, but with persistence you'll see some beautiful examples. Keep Some Snowflakes
Piece of glass Hairspray You can have a permanent record of your caught snowflakes if you freeze a piece of glass and the hairspray before the next snowfall. (Both may be stored in the freezer until you need them.) When your ready to collect some snowflakes, spray your chilled glass with the chilled hairspray and go outside and let some snowflakes settle on the glass. When you have enough flakes bring the glass indoors and allow it to thaw at room temperature for about 15 min. Now you have a permanent record of your snowflakes!
Snow pit analysis, profile stability, subniven habitats, hydrology
rates for sublimation, evapotransportation
water - snow storage, atmospheric uptake
insects under snow, insect traps, winter activity
microtines under snow, mouse tracks at snow base
quinzie and igloo construction, stability and insulating qualities
development of snow pit charts, snow depth measures
track and track casts in snow
Caribou behaviour in different snow depths
Mt Sima keep snow in cold climates, destructive metamorphism
effects on ground temp. packing snow
permafrost active layer studies, ground temp variation