Unexpectedly High Aerosol Load in the Free Troposphere Observed With Raman Lidar in Central Europe in Spring/Summer 2003
Abstract
We present spectrally resolved backscatter and extinction coefficients, particle optical depths, {Å}ngström exponents, extinction--to--backscatter ratios, and depolarization ratios of strongly enhanced particle loading in the free troposphere. The observations were made with Raman lidar at 355 and 532~nm wavelength at Leipzig (51.3o~N, 12.4o~E), Germany. Particle extinction coefficients were 5--30~Mm-1 in the free troposphere from May to July, 2003. These numbers result in particle optical depths of 0.03--0.12 at the ultraviolet and visible wavelengths. In May and early June distinct aerosol layers could be observed above the boundary layer, which typically was between 3 and 7-km height. By the end of June and in July the aerosol distribution became vertically more homogeneous and reached up to the tropopause. On the basis of satellite imagery and backward trajectory analysis it is most likely that severe forest fires in Siberia in early spring 2003 caused this enhanced free tropospheric background. Additional significant sources of the observed aerosols may have been strong forest fires in western Canada in the summer 2003.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2003
- Bibcode:
- 2003AGUFM.A22C1089M
- Keywords:
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- 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0305 Aerosols and particles (0345;
- 4801);
- 0365 Troposphere: composition and chemistry;
- 0368 Troposphere: constituent transport and chemistry;
- 3360 Remote sensing