Time series of freshwater-transport on the East Greenland Shelf at 74N

Abstract

The major flux of freshwater from the Arctic Ocean to the convective regions in the Nordic Seas and the Northern North Atlantic is linked to the shelf branches of the East Greenland Current. This flux is partitioned into a solid (ice) and a liquid phase. Time series measurements of the liquid component are hard to obtain since the seasonally varying ice cover prevents the use of standard moored instrumentation in the near surface gradient layers where most of the freshwater transport takes place. Using 40m-polyethylene tubes to protect sensors and buoyancy in the upper portion of the moorings and employing a bottom-mounted acoustic Doppler current pro filer have yielded the first time series of upper layer temperatures, salinities and currents for a location at the outer East Greenland shelf at 74°N. The observed seasonal variability suggests the dominance of local warming/cooling and melting/freezing rather than advective processes. Estimates of liquid freshwater transport yield a mean of 869 km3/a, whereas the total freshwater transport amounts to a value between 1250 to 1750 km3/a.