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IAOOS winter SIMBA data during N-ICE 2015 North of Svalbard
Two ice mass balance instruments (part of IAOOS7 and IAOOS8 platforms) deployed near 83°N on the same ice floe, documented the evolution of snow and ice conditions in the Arctic Ocean north of Svalbard in Jan-Mar 2015. Frequent profiles of temperature (every 3 hours) and temperature change after 30s and 120s heating (once a day) were recorded. The ratio of the temperature changes after heating provides a proxy for thermal diffusivity. Both instruments documented flooding and snow-ice formation. Flooding was clearly detectable in the simultaneous changes in thermal diffusivity proxy, increased temperature, and heat propagation through the underlying ice. Slush then progressively transformed into snow-ice. Flooding resulted from two different processes; i) after storm-induced break-up of snow-loaded floes for IAOOS8 and ii) after loss of buoyancy due to basal ice melt for IAOOS7. The instrument on IAOOS7 documented basal sea-ice melt over warm Atlantic waters and ocean-to-ice heat flux peaked at up to 400 Wm-2 in winter.
Disciplines
Cryosphere
Keywords
sea ice, snow, ice growth, basal melt, flooding, snow-ice, mass balance
Location
84N, 80S, 5E, 25W
Devices
On both IAOOS7 and IAOOS8 platforms, the ice instrument is a SIMBA (SAMS Ice Mass Balance for the Arctic). A SIMBA comprises a GPS and a 5 m long chain cable hanging through air, snow, sea-ice and ocean. The chain comprises solid-state sensors located every 2 cm measuring temperature at approximately 0.18°C accuracy (resolution 1/16°C). The SIMBA also features a heating mode which can be used to discriminate between different media, especially between snow and ice [Jackson et al., 2013].