Mass and heat balance of snowpatches in Basen nunatak, Dronning Maud Land, Antarctica, in summer

An experimental study concerning the mass and heat balance of snowpatches was performed during the Finnish Antarctic Research Programme (FINNARP) 2004 and 2010 summer expeditions to Basen nunatak (73 degrees 03'S, 13 degrees 25'W). Data were collected from a snow stake line, snow pits and automated weather and snow recording systems. One 100 m perennial snowpatch and several smaller seasonal patches (<10 m) were monitored. Snow thickness decreased by 4.0-6.3 mm d(-1) due to sublimation, compression and, close to lateral boundaries, meltwater runoff. The vertical mass loss was 1-2 mm snow water equivalent (SWE) d(-1) and the lateral decay was similar to 10 cm d(-1). The net radiation was 20.2 W m(-2) and the mean latent heat flux was -15.5 W m(-2). The mean surface energy flux was 4.9 W m(-2) and the heat loss to the ground was 1.5 W m(-2). Thin snow decayed faster due to surface thermomechanical erosion and melt from the bottom where the soil was heated by the solar radiation. Between the summers of 2004 and 2010, the thickness of the perennial snowpatch decreased by 230 mm.