ELSEVIER Global and Planetary Change 9 (1994) 53-67 GLOBAL AND PLANETARY CHANGE Simulation of the atmospheric circulation near the Greenland ice sheet margin A.G.C.A. Meesters, E.A.C. Henneken, N.J. Bink, H.F. Vugts, F. Cannemeijer Free UniL'ersityAmsterdam, Faculty of Earth Sciences, Department of Meteorology, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands (Received October 17, 1992; revised and accepted May 5, 1993) Abstract A two-dimensional mesoscale atmospheric model, which has been developed to simulate the air circulation at the margin of the Greenland ice sheet, is described. The model contains a detailed multi-level parameterisation of the surface of the ice sheet and the tundra. Model results for 12 July 1991, a day with calm and stationary large-scale weather, are described, and compared to the GIMEX measurements for that day. The agreement between observations and simulation is on the whole satisfactory. Above the ice sheet, good results are obtained for the temperature and wind in the (shallow) boundary layer, except at its top. At the ice margin, there is agreement concerning the temperature. The simulated wind is acceptable as a grid-point average, though the resolution is too small to reproduce some observed small-scale features. The latter is expected from the heterogeneity of the terrain. I. Introduction The Greenland Ice Margin Experiment (GIMEX, see Oerlemans and Vugts, 1993) has been set up to obtain a better understanding of the present mass balance of the Greenland ice sheet, and its response to future climate change. The location of the involved stations is shown in Fig. 1 in Van den Broeke et al. (1994), elsewhere in this volume. Especially for what concerns prediction, nu- merical simulation is a necessary complement of the observations that have been performed. A model that can execute such simulations should be well adapted to the peculiar features of the region. Such features are, for what concerns the atmosphere, the presence of a rather deep cold 0921-8181/94/$07.00 © 1994 Elsevier Science B.V. All rights SSDI 0921-8181(94)E0063-5 and stable boundary layer above the ice sheet and the almost unceasing katabatic flow. Others are the mesoscale circulations that can develop above the tundra-ice and the sea-land transitions, and that are modified by the presence of mountains at the margin of Greenland. The situation for Greenland differs strongly from the situation for Antarctica, for which numerical simulations have already been done from various viewpoints (Parish, 1984; Parish and Waight, 1987; Kottmeier 1988; Gall6e and Schayes, 1992; Fortuin, 1992). Major differences are the presence of the ex- posed tundra, and the occurrence of melting dur- ing summer. The katabatic wind is in general weaker for Greenland than for Antarctica, mainly because of the smaller area and smaller average height, and of the consequently larger incoming reserved