SIMULATION OF SUMMER SNOWMELT ON THE GREENLAND ICE-SHEET USING A ONE-DIMENSIONAL MODEL

A one-dimensional heat and mass balance model of a snowpack over froze n soil was modified for use in glacial environments. The model solves a set of governing equations for the energy and mass balances of the s now, subject to observed meteorological conditions at the upper bounda ry and the assumption of a steady state at the lower boundary. The ini tial state of the snowpack is defined by the temperature, density and grain size profiles at the beginning of the simulation period. The dat a used to test the model on the Greenland ice sheet are a subset of th e meteorological and surface data collected during the 1990 summer fie ld season by the Swiss Federal Institute of Technology (ETH) Greenland Expedition. The site was located near the equilibrium line elevation on the west slope of the ice sheet. The relatively large amount of sno wmelt experienced at this site during the summer of 1990 provides a ro bust test of the snowmelt model. Both the simulated height and mass of the snowpack agree well with the observations. The evolution of profi les of temperature, density and liquid water content also conform to o ur expectations of the physical changes taking place in the snowpack d uring melt. Results from the present model. are also compared to those from a similar model and differences between the models are discussed .