Modeling dust emissions and transport within Europe : the Ukraine march 2007 event

International audienceA dust event was observed in Europe on 23-25 March 2007. Surface observations in Central Europe showed huge concentrations of particulate matter (PM). At the same time, dust models diagnosed a Saharan dust outbreak flowing from Sahara to Europe. However, lidar measurements and surface stations in Eastern Europe diagnosed a dust event originating from Ukraine related to chernozemic-erodible lands. Using surface and satellite measurements with modeling results, it is demonstrated that the finally huge surface concentrations recorded in the Netherlands, Belgium, and the north of France were mostly due to the extremely rare Ukraine dust event, whereas Saharan dust events usually produce only midtroposphere plumes. To investigate this episode, the chemistry-transport model CHIMERE is modified to account for the erodibility of chernozemic soil inside Europe. A size distribution for chernozemic dust emission is proposed. Over Western Europe, the model reproduces the observed PM concentration peaks up to 200 mu g m(-3), with a large contribution of Ukraine dust, up to 170 mu g m(-3). This first model study of dust emissions due to European arable land shows that it is possible to fairly retrieve the magnitude of surface concentrations far away from the emission source