Present and future Greenland ice sheet surface energy balances with the help of the regional climate MAR model

• Main Author: Franco, Bruno
• Other Authors: Erpicum, Michel, Fettweis, Xavier, Laboratoire de Climatologie et Topoclimatologie, Département de Géographie, ULiège
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: ULiège - Université de Liège 2012
• Subjects: Greenland ice sheet; surface energy balance; MAR model; Physical; chemical; mathematical & earth Sciences; Earth sciences & physical geography; Physique; chimie; mathématiques & sciences de la terre; Sciences de la terre & géographie physique; Greenland; Ice Sheet; North Atlantic; North Atlantic oscillation
• Online Access: https://orbi.uliege.be/handle/2268/132087; https://orbi.uliege.be/bitstream/2268/132087/1/abstract-and-contents.pdf

See enclosed abstract-and-contents.pdf The Greenland ice sheet (GrIS) surface mass balance (SMB) was modelled at different spatial resolutions (15-50 km), using the regional climate model MAR (Modèle Atmosphérique Régional) forced by the ERA-INTERIM reanalysis over the 1990-2010 period. The comparison of these simulations revealed that (i) the inter-annual variability of the SMB components is consistent within the different resolutions investigated when they are integrated over the whole ice sheet, (ii) the MAR model simulates heavier precipitation on average over the GrIS with decreasing resolution, and (iii) the SMB components (except precipitation) can be derived from a lower-resolution simulation with an enhanced interpolation. This interpolation can also be used to approximate the SMB components over another topography/ice sheet mask of the GrIS. These results are valuable for the forcing of an ice dynamical model, needed to enable full projections of the GrIS mass balance contribution to sea-level rise (SLR) over the coming centuries. Moreover, this work showed that 25 km-resolution MAR simulation is a good compromise between computing time and results precision in the aim to perform afterwards 21st-century projections of the GrIS melt. The most suited atmosphere-ocean general circulation models (AOGCMs) for the GrIS current climate modelling were selected on the basis of comparison between the 1970-1999 outputs and reanalyses, showing that the representation quality of surface parameters (temperature, precipitation) are highly correlated to the atmospheric circulation and its inter-annual variability (North Atlantic oscillation). Future atmospheric circulation changes according to greenhouse gas (GHG) emissions scenarios were projected to dampen the zonal flow, enhance the meridional fluxes and provide additional heat and moisture to the GrIS, increasing temperature over the whole ice sheet and precipitation over its northeastern area. Moreover, future projections performed with the selected AOGCMs ...