Ground-based lidar measurements from Ny-Ålesund during ASTAR 2007: a statistical overview
1Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association, Telegrafenberg A 43, 14473 Potsdam, Germany
2National Institute of Polar Research, Kaga 1-9-10, Itabashi-ku, Tokyo, 190-8518 Japan
3Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association, Bürgermeister-Smidt-Straße 20, 27568 Bremerhaven, Germany
Abstract. During the Arctic Study of Tropospheric Aerosol, Clouds and Radiation (ASTAR) in March and April 2007, measurements obtained at the AWIPEV Research station in Ny-Ålesund, Spitsbergen (operated by the Alfred-Wegener-Institute for Polar and Marine Research and the Institut polaire français Paul-Emile Victor), supported the airborne campaign. This included Lidar data from the Koldewey Aerosol Raman Lidar (KARL) and the Micro Pulse Lidar (MPL), located in the atmospheric observatory as well as photometer data and the daily launched radiosonde. The MPL features nearly continuous measurements; the KARL was switched on whenever weather conditions allowed observations (145 h in 61 days). From 1 March to 30 April, 71 meteorological balloon soundings were performed and compared with the corresponding MPL measurements; photometer measurements are available from 18 March. For the KARL data, a statistical overview based on the optical properties backscatter ratio and volume depolarization can be given. The altitudes of the occurrence of the named features (subvisible and visible ice and water as well as mixed-phase clouds, aerosol layers) as well as their dependence on different air mass origins are analyzed. Although the spring 2007 was characterized by rather clean conditions, diverse case studies of cloud and aerosol occurrence during March and April 2007 are presented in more detail, including temporal development and main optical properties as backscatter, depolarization and extinction coefficients. Links between air mass origins and optical properties can be presumed but need further evidence.