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Abstract
At the AWIPEV research base in Ny-Ålesund, Spitsbergen (79°N, 12°E), a broad atmospheric profiling program is operated. Apart from the specific measurements of e.g. aerosols by lidar, vertical profiles of meteorological parameters like temperature, humidity and wind are monitored by radiosondes on a daily basis. These regular observations are complemented by campaign-based measurements. Here, we present the meteorological profiling of the planetary boundary layer (PBL) with a tethered balloon system. The PBL is the lowest part of the atmosphere, where exchange processes of momentum and heat occur between the Earth's surface and the atmosphere. In the Arctic, the boundary layer is characterized by a frequent occurrence of temperature inversions, thus being a stable layer that effectively suppresses the vertical motion of air. The Ny-Ålesund environment, with its semi-permanent snow cover in the vicinity of glaciers and mountainous orography, sets up special atmospheric boundary layer conditions. Also presented are field studies performed on the drifting ice station NP-35 in the Arctic Ocean during polar night 2007-2008, representing sea ice surface conditions.
Our analyses focus on the spatial and temporal characterization of the Arctic PBL. Hence, the experimental set-up includes up to 6 tethersondes mounted along the tether, measuring a meteorological profile over several hours. The results are used e.g. to validate the boundary layer representation in the regional climate model HIRHAM under different atmospheric stability conditions due to synoptic scale influences.