Albedo of forest with crown snow

Abstract

Follwing are results of measurements of albedo and snowfall in forests. (1) Albedo of forest without crown snow becomes large with increasing solar zenith angle and becomes small with increasing cloud amount. (2 ) Albedo of forest with crown snow increases with the increase of areal ratio of crown snow to the whole forest area ( crown-snow ratio), but its relationship is nonlinear. (3) After snowfall the crown-snow ratio decreases exponentially with time, depending on the air temperature and wind speed. The response time of the ratio is about 1/2 day when the air temperature is below0°C, and 15 hrs when it is above 0°CHowever, strong wind affects the response time shorter and the freezing of leaves after rain affects it longer. (4) The amount of crown-intercepted snow is large in dense evergreen forest, while there is no difference among deciduous forests.