The aim of this work is to assess potential future Antarctic surface
mass balance changes, the underlying mechanisms, and the impact of these
changes on global sea level. To this aim, this paper presents
simulations of the Antarctic climate for the end of the 20th and 21st
centuries. The simulations were carried out with a stretched-grid
atmospheric general circulation model, allowing for high horizontal
resolution (60 km) over Antarctica. The simulated present-day surface
mass balance is evaluated. It is found that the simulation is good on
continental scales. Errors on regional scales are moderate when observed
sea surface conditions are used; more significant regional biases appear
when sea surface conditions from a coupled model run are prescribed. The
simulated Antarctic surface mass balance increases by 20 mm water
equivalent per year in the next century, corresponding to a sea level
decrease of 0.78 mm yr-1 by the end of the 21st century. This surface
mass balance increase is largely due to precipitation changes, while
changes in snow melt and turbulent latent surface fluxes are weak. The
temperature increase leads to an increased moisture transport towards
the interior of the continent because of the higher moisture holding
capacity of warmer air, but changes in atmospheric dynamics, in
particular off the Antarctic coast, regionally modulate this signal.

Last Updated: 2006-03-30