Atmospheric boundary conditions of recent Saharan dust influx into Central Europe

Abstract

During the period October 1987 to Oktober 1988 the exceptionally high frequency of eight cases of Saharan dust fallout was observed at Bochum University meteorological station, FR Germany. The main source areas of this long-range transport material were on both sides of the Atlas region, in the Algerian and Libyan Sahara and in various parts of the Sahelian zone. Surface and 500 hPa-layer chart analysis gives useful information on the trajectory evolution of the respective dust plumes. Once the material is lifted to this significant pressure level, upper tropospheric circulation leads to characteristic influx routes into Central Europe depending on the strength and position of the zonal wind component of the west wind drift in the Atlantic and European sectors. In both sectors a typical seasonal pattern of a meridional dust plume influx is confirmed. In this context, Saharan dust transport to Europe is not an anomaly in tropospheric circulation but an increased frequency of fallout events should have its reasons in variations of intercontinental atmospheric teleconnections.