Snow-accumulation distribution in the interior of the Lambert Glacier Basin, Antarctica

A prime input variable to uncoupled ice-sheet models, or for estimating the mass budget of present-day ice sheets, is the distribution of net surface mass balance. In most cases this is extrapolated from relatively few direct measurements over a limited time period, and parameterised in terms of continentality, surface elevation and other broad-scale indicators. Between 1989 and 1995 a series of oversnow traverses around the interior of the Lambert Glacier basin gathered a comprehensive set of data on snow accumulation and surface properties, surface climatology, ice-sheet velocities, elevations and thicknesses. Above the 2000 m level accumulation averages were found to be 76 kg m(-2) a(-1) (sigma = 74), much lower than at similar elevations in Wilkes Land. The traverse route contains three distinct accumulation regimes: a relatively high accumulation zone along the western side despite higher average elevations, a very low accumulation zone in the south due to the effect of increased continentality and an eastern sector that exhibits a rain-shadow effect in predominantly easterly wind fields. Inter-annual variability is high, with 1993 a colder year. recording only half the longer term average accumulation over the portion of the route that was measured.