Meridional gradients of light absorbing carbon over northern Europe

In situ measurements have been made in the upper troposphere of the properties of particles containing light absorbing carbon (LAC). These measurements, made in late November 2006 over northern Europe, show that the average LAC mass concentration varies between 1 and 5 ng m−3 over a latitude range 50° to 70°N, with maxima at 50° and 66°. The relative fraction of all particles larger than 0.1 µm that contain LAC decreases at higher latitudes. The derived extinction coefficient, which also increases with latitude, reaches a maximum of 1.4 Mm−1 at 66°. The air mass histories associated with the LAC were evaluated with back trajectory analysis using wind field analysis from the European Center …