The Energy Balance of Dry Tundra in West Greenland

Abstract

The energy fluxes over dry tundra were measured during the period mid-May to mid-June 1988 in Western Greenland at 67°N as contribution to a field campaign of the International Satellite Land Surface Climatology Experiment (ISLSCP). In addition to the energy balance station, which was situated about 4 km west of the margin of the inland ice, standard meteorological data were collected at two stations a few kilometers south and west, respectively, from the energy balance site. While air temperature shows little differences between the stations, the wind patterns are strongly modified by comparatively small-scale topography and show clearly decreasing influence of catabatic flow already at scales of a few kilometers from the ice margin. The temporal variations of the energy fluxes are dominated by the incoming solar radiation and the availability of moisture at the soil surface. Desiccation of the soil crust during the first 2 wk of the observation period resulted in decrease of evaporation. On the average, the sensible heat flux clearly surpassed the latent heat flux. Evapotranspiration sums of various surface types, including dry tundra and a swamp, were measured twice daily with lysimeters. Daily evapotranspiration was found to be closely related to net radiation and to the difference between air temperature and surface temperature, which offers the opportunity to apply satellite data for estimation of the latent heat flux.