Abstract: A small-size meteorological mast, BEAR (Budget of Energy for Arctic regions) has been developed as a part of a new autonomous buoy for monitoring the sea ice mass balance. BEAR complements observations of the thickness and thermodynamic properties of the ice/snow pack determined by the so-called Ice-T (Ice-Thickness) buoy, giving access to bulk fluxes and energy budget at the surface, using meteorological measurements. The BEAR mast has been tested with success during ten days in April-May 2010 at Ny Alesund, in the Svalbard archipelago (Norway) showing that meteorological data were close to measurements at the same level of the Italian Climate Change Tower (CCT) from the ISAC-CNR. A discussion is undertaken on bulk fluxes determination and uncertainties. Particularly, the strategy to systematically use different relevant fluxes parameterizations is pointed out to explore flux range uncertainty before to analyze energy budget. Net radiation, bulk fluxes and energy budget are estimated using as average 10 minutes, 24 hours and the ten days of the experiment. The observation period was very short, but we observe a spring transition when the net radiation begins to warm the surface while the very small turbulent heat flux cools the surface.

Abstract: Hydrographic and velocity measurements were taken over four different time periods from April to May 2005–2007 at adjacent stations in Storfjorden, Svalbard. Different environmental conditions, including winds, ice cover, and water mass contributions, yield notably different stratification (N2) profiles among the time series. When classified according to the Gerkema (2001) classification system, the stratification profiles span the spectrum with two profiles resembling that of a two-layer fluid, one resembling more closely a fluid of constant stratification, and one falling in between the two extremes. The different N2 profiles elicit sharply contrasting modal responses from the internal wave field, which is dominated by mode 1 during the two time series most resembling a two-layer fluid, and nearly evenly spread out among the first five modes during the time series with a nearly constant stratification. Turbulent dissipation rates determined from fine-scale parameterizations reveal an average rate on the order of 10−9Wkg−1 for all time series with an associated average diapycnal diffusivity of 10−5m2s−1–10−4m2s−1. Turbulent heat fluxes, determined from the estimated turbulent dissipation rates, ϵ, were found to have a relative maximum at the tops of the pycnoclines, with values up to 1Wm−2, typical of ice-covered conditions. The turbulent dissipation rate and diapycnal diffusivities for each time series vary with the Gerkema (2001) stratification profile rankings, and are elevated for the time series most resembling a fluid of constant stratification, and reduced for the time series most similar to a two-layer fluid.