Articles | Volume 15, issue 9
Research article
04 May 2015
Research article |  | 04 May 2015

Lidar profiling of aerosol optical properties from Paris to Lake Baikal (Siberia)

E. Dieudonné, P. Chazette, F. Marnas, J. Totems, and X. Shang

Abstract. In June 2013, a ground-based mobile lidar performed the ~10 000 km ride from Paris to Ulan-Ude, near Lake Baikal, profiling for the first time aerosol optical properties all the way from western Europe to central Siberia. The instrument was equipped with N2-Raman and depolarization channels that enabled an optical speciation of aerosols in the low and middle troposphere. The extinction-to-backscatter ratio (also called lidar ratio or LR) and particle depolarization ratio (PDR) at 355 nm have been retrieved. The LR in the lower boundary layer (300–700 m) was found to be 63 ± 17 sr on average during the campaign with a distribution slightly skewed toward higher values that peaks between 50 and 55 sr. Although the difference is small, PDR values observed in Russian cities (>2%, except after rain) are systematically higher than the ones measured in Europe (<1%), which is probably an effect of the lifting of terrigenous aerosols by traffic on roads. Biomass burning layers from grassland or/and forest fires in southern Russia exhibit LR values ranging from 65 to 107 sr and from 3 to 4% for the PDR. During the route, desert dust aerosols originating from the Caspian and Aral seas regions were characterized for the first time, with a LR (PDR) of 43 ± 14 sr (23 ± 2%) for pure dust. The lidar observations also showed that this dust event extended over 2300 km and lasted for ~6 days. Measurements from the Moderate Resolution Imaging Spectrometer (MODIS) show that our results are comparable in terms of aerosol optical thickness (between 0.05 and 0.40 at 355 nm) with the mean aerosol load encountered throughout our route.

Short summary
In June 2013, a ground-based mobile lidar performed the 10,000km ride from Paris to Ulan-Ude, near Lake Baikal. Aerosols have been characterized using two intensive properties: extinction-to-backscatter ratio and particle depolarization ratio. The results highlight spatial variations in the aerosol mix, with more terrigenous particles over Russia than Europe. Wildfire and desert dust plumes were also observed, offering the first optical characterization of dust from the Caspian–Aral region.
Final-revised paper