On turbulence characteristics at Ny-Alesund-Svalbard

The unique data set collected at the climate change tower (CCT) installed in the Arctic site of Ny-lesund, Svalbard, allows to investigate the peculiar features of the high-latitude planetary boundary layer under different stability conditions. The analysis uses four conventional Young anemometers and Vaisala thermo-hygrometers, alternated by three lined up sonic anemometers, installed on the CCT between 2 and 33.4 m a.g.l. The data are averaged over 10 min. The results presented here highlight the problematic behavior of the vertical mixing in quasi-neutral, low-wind conditions and the properties of the similarity scaling in unstable conditions, coupled with the evaluation of the scaled second-order moments of velocity and temperature. As far as stable cases are considered, the vertical profiles of the mean velocity and of the momentum and heat fluxes are shown, for high- and low-wind conditions and for traditional and upside-down cases, respectively.