Volcanic aerosol layers observed with multi-wavelength Raman lidar over Europe since summer 2008

In the framework of regular EARLINET observations aerosol layers can be observed in the upper troposphere lower stratosphere (UTLS) region above Europe since summer 2008. FLEXPART transport simulations show that the origin of those layers are eruptions of different volcanoes on the Aleutian Islands, Kamchatka, Alaska, and on the Kuril Islands. The aerosol layers extended up to a maximum height of 30 km whereas the strongest aerosol layers could be found in the tropopause region. Optical depth at 532 nm was in the range between 0.004 and 0.016. Multi-wavelength Raman lidar observations over Leipzig show a strong wavelength dependence of the backscatter coefficients and extinction coefficients. Lidar ratios at 355 nm are significantly larger than those at 532 nm. The effective radius was estimated to be 0.1μm.