|
E. Linacre |
5/'99 |
Energy fluxes, including net radiation, evaporation, and precipitation, in polar regions are much smaller than those at low latitudes. In addition, the seasonal variation of these fluxes can be very large, as in northern Canada.
The latent-heat flux (evaporation, condensation, etc) in northern Canada can be estimated as a ratio of the net radiation, for various types of terrain (1). This ratio varies from about 0.85 for a shallow tundra lake, 0.65 for tundra fens and bogs, to 0.45 for a deep large lake, and 0.15 for a young pine forest.
The water balance for a small tributary to the Mackenzie River over a year was as follows:
|
flux |
water-equivalent depth (mm) |
|
snow deposition |
190 |
|
rain |
86 |
|
net advection of blowing snow |
51 |
|
total inputs |
327 |
|
sublimation of the snow pack |
34 |
|
evaporation |
203 |
|
run-off and transport into the Mackenzie |
98 |
|
total losses |
335 |
Reference
(1) Stewart, R.E. et al. 1999. The Mackenzie GEWEX study. Bull. Amer. Meteor. Soc., 79, 2665- 83.