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www.atmos-chem-phys-discuss.net/9/15125/2009/
doi:10.5194/acpd-9-15125-2009
© Author(s) 2009. This work is distributed
under the Creative Commons Attribution 3.0 License.
Observations of boundary layer, mixed-phase and multi-layer Arctic clouds with different lidar systems during ASTAR 2007
1Alfred Wegener Institute for Polar and Marine Research, 14473 Potsdam, Germany
2Laboratoire de Météorologie Physique UMR 6016 CNRS/Université Blaise Pascal, France
3Johannes Gutenberg-University Mainz, Institute for Atmospheric Physics, 55099 Mainz, Germany
4Institute of Atmospheric Physics, DLR Oberpfaffenhofen, 82234 Oberpfaffenhofen, Germany
5National Institute of Polar Research, Tokyo 190-8518, Japan
*now at: Leipzig Institute for Meteorology (LIM), University of Leipzig, 04109 Leipzig, Germany
Abstract. During the Arctic Study of Tropospheric Aerosol, Clouds and Radiation (ASTAR), which was conducted in Svalbard in March and April 2007, tropospheric Arctic clouds were observed with two ground-based backscatter lidar systems (micro pulse lidar and Raman lidar) and with an airborne elastic lidar. An increase in low-level (cloud tops below 2.5 km) cloud cover from 51% to 65% was observed above Ny-Ålesund during the time of the ASTAR campaign. Four different case studies of lidar cloud observations are analyzed: With the ground-based Raman lidar, a pre-condensation layer was observed at an altitude of 2 km. The layer consisted of small droplets with a high number concentration (around 300 cm−3) at low temperatures (−30°C). Observations of a boundary layer mixed-phase cloud by airborne lidar were evaluated with the measurements of concurrent airborne in situ and spectral solar radiation sensors. Two detailed observations of multiply layered clouds in the free troposphere are presented. The first case was composed of various ice layers with different optical properties detected with the Raman lidar, the other case showed a mixed-phase double layer and was observed by airborne lidar.
The analysis of these four cases confirmed that lidar data provide information of the whole range from subvisible to optically thick clouds. Despite the attenuation of the laser signal in optically thick clouds and multiple scattering effects, information on the geometrical boundaries of liquid water clouds were obtained. Furthermore, the dominating phase of the clouds' particles in the layer closest to the lidar system could be retrieved.
Discussion Paper (PDF, 2804 KB) Interactive Discussion (Closed, 6 Comments) Manuscript under review for ACP Special Issue
Citation: Lampert, A., Ritter, C., Hoffmann, A., Gayet, J.-F., Mioche, G., Ehrlich, A., Dörnbrack, A., Wendisch, M., and Shiobara, M.: Observations of boundary layer, mixed-phase and multi-layer Arctic clouds with different lidar systems during ASTAR 2007, Atmos. Chem. Phys. Discuss., 9, 15125-15179, doi:10.5194/acpd-9-15125-2009, 2009. Bibtex EndNote Reference Manager XML
