Siberian forest-fire smoke observed over central Europe in spring/summer 2003 in the framework of earlinet

Abstract

We observed unexpectedly high particle backscattering and extinction in the free troposphere over Leipzig, Germany, in spring/summer 2003. Optical depth was about four times higher than in the respective months of 2000-2002. Satellite observations and Lagrangian particle dispersion simulations indicated that forest fires in Siberia were the source of this high aerosol load. The smoke of these fires was transported in two directions: One part of the plume travelled westward directly to central Europe, the other part of the plume travelled in easterly directions around the globe. We present a detailed measurement example of ? ay 29, 2003. On this day we observed layers of both transport paths over Leipzig,. The eastward travelling layer was observed over Tokyo, Japan, a few days before it arrived over Leipzig. The observations in the free troposphere over Leipzig and Tokyo were performed with Raman lidars which operate at 355 and 532nm wavelength. This configuration allows a clear identification of aged smoke in terms of spectrally resolved backscatter coefficients, extinction coefficients, and lidar ratios as well as Angstrom exponent and depolarization ratio. The microphysical aerosol properties effective radius, volume and surface-area concentration, and single-scattering albedo were determined from the optical data measured over Leipzig and Tokyo by inversion with regularization.