Characteristics of the boundary layer at Ny-Ålesund in the Arctic during the ARTIST field experiment

A preliminary analysis of boundary layer data acquired during the Arctic Radiation and Turbulence Interaction Study Experiment (ARTIST) at Ny-Ålesund (Spitzbergen) in 1998 is presented. As expected, the wind field and the thermal structure of the boundary layer are strongly influenced by the katabatic flow blowing along the Kongsfjorden. In particular, if the large scale circulation has a component along the same direction, the resulting low level wind reaches velocities comparable with geostrophic wind. Stable to neutral conditions occurred most of the time, sustaining inversion or spiky layers respectively, depending on the wind intensity. The behaviour of some micrometeorological parameters was examined in relation to the general flow pattern and the characteristics of this area. The highest values of surface sensible heat flux (with negative sign) were observed during daytime, in presence of forced convection, due to the transfer of warmer upper layer air into the surface layer.