Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 16, 11535-11546, 2016
https://doi.org/10.5194/acp-16-11535-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
16 Sep 2016
Saharan dust contribution to the Caribbean summertime boundary layer – a lidar study during SALTRACE
Silke Groß1, Josef Gasteiger2, Volker Freudenthaler2, Thomas Müller4, Daniel Sauer1, Carlos Toledano3, and Albert Ansmann4 1Deutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Münchner Str. 20, 82234 Oberpfaffenhofen, Germany
2Ludwig-Maximilians-Universität, Meteorologisches Institut, Theresienstr. 37, 80333 München, Germany
3Universitat de Valladolid, Valladolid, Spain
4Leibniz-Institut für Troposphärenforschung (TROPOS), Permoserstr. 15, 04318 Leipzig, Germany
Abstract. Dual-wavelength lidar measurements with the small lidar system POLIS of the Ludwig-Maximilians-Universität München were performed during the SALTRACE experiment at Barbados in June and July 2013. Based on high-accuracy measurements of the linear depolarization ratio down to about 200 m above ground level, the dust volume fraction and the dust mass concentration within the convective marine boundary layer can be derived. Additional information from radiosonde launches at the ground-based measurement site provide independent information on the convective marine boundary layer height and the meteorological situation within the convective marine boundary layer. We investigate the lidar-derived optical properties, the lidar ratio and the particle linear depolarization ratio at 355 and 532 nm and find mean values of 0.04 (SD 0.03) and 0.05 (SD 0.04) at 355 and 532 nm, respectively, for the particle linear depolarization ratio, and (26 ± 5) sr for the lidar ratio at 355 and 532 nm. For the concentration of dust in the convective marine boundary layer we find that most values were between 20 and 50 µgm−3. On most days the dust contribution to total aerosol volume was about 30–40 %. Comparing the dust contribution to the column-integrated sun-photometer measurements we see a correlation between high dust contribution, high total aerosol optical depth and a low Angström exponent, and of low dust contribution with low total aerosol optical depth.

Citation: Groß, S., Gasteiger, J., Freudenthaler, V., Müller, T., Sauer, D., Toledano, C., and Ansmann, A.: Saharan dust contribution to the Caribbean summertime boundary layer – a lidar study during SALTRACE, Atmos. Chem. Phys., 16, 11535-11546, https://doi.org/10.5194/acp-16-11535-2016, 2016.
Publications Copernicus
Download
Short summary
Dual-wavelength depolarization sensitive Raman lidar measurements were used to characterize the optical properties of the dust loaded convective boundary layer over the Caribbean. Furthermore we derived the dust volume fraction and dust mass concentration within the convective boundary layer.
Dual-wavelength depolarization sensitive Raman lidar measurements were used to characterize the...
Share