|THE COOLING EFFECTS OF SURFACE SNOW COVER
METEOROLOGIST JEFF HABY
Surface snow cover cools
high and low temperatures from the values they would be. Three types of
latent heat can be absorbed
from snow and they are melting, evaporation and sublimation. During the day, just like
clouds, snow cover is a good
reflector of shortwave radiation from the sun. This is especially true of fresh snow. At night, snow cover is a good
emitter of longwave radiation.
Often record low temperatures occur on a night with surface snow cover. The sublimational and longwave cooling
from the snow cover makes the low colder than it would otherwise would be. During the day, evaporation and
melting promote cooling. This along with reflection keeps daytime temperatures cool.