Meteorology and Duststorms in Central Iceland
Ian Y. Ashwell
Glaciogenic silt forms an important component of mineral soils around the coastal lowlands of Iceland, but wind erosion on and around the margin of the central plateau is a serious problem. Previous observations in central Iceland have suggested that more than one process is involved in the lifting of material of various sizes. First, winds blowing from the icecaps can raise material of sand size and transport it fairly near the ground for some distance from the ice edge. Second, clear skies in the lee of icecaps cause marked heating of the ground surface, formation of a "heat low" in the afternoon with superadiabatic lapse rates and convectional lifting of silt-sized material to be carried long distances in the atmosphere. There appear to be intermediate stages between these two types. Most situations seem to be associated with topographic disturbances in the atmospheric circulation. These hypotheses were tested in the summer of 1981 by observations made just to the north of the largest icecap, Vatnajökull (8400 km2), which would be expected to cause the greatest topographic disturbance of the southwesterly circulation with the most extensive duststorms. The hypotheses were supported and it is suggested that the atmospheric waves associated with the duststorms are not only primary, resulting from local topography, but may in some cases result from disturbances in the global wind circulation.
Citation Note: This article was published when our journal had an earlier shorter name: "Arctic and Alpine Research."