Characterization of seawater properties and ocean heat content in Kongsfjorden, Svalbard Archipelago

Abstract

Increased melting of tidewater glaciers had been widely reported in Greenland and Svalbard, and one possible reason has been attributed in the interaction of warming ocean water with the portion of the ice terminus in contact with the sea. In Kongsfjorden, there are five major tidewater glaciers positioned in the innermost part of the fjord and it experiences a periodic intrusion of warm water of Atlantic origin down to the innermost part. These warm veins are expected to provide the heat for melting of tidewater glaciers. The aim of this paper is to report on the hydrology and ocean heat content (OHC) in Kongsfjorden, especially focussing on its innermost part. OHC estimates were based on calculations of the volume of water in the major basins of Kongsfjorden as inferred by a dedicate and accurate bathymetric survey and by CTD casts. Ocean water after interaction with freshwater of glacial origin evidenced a drop in temperature up to 2 $$^{\circ }$$ C. We calculated OHC over a profile ranging from the lower limit of surface fresh water exiting the fjord (−7.5 m) to 40 m depth m, assuming deeper heat was not relevant to regularly interact with glaciers because of the depth of the submerged moraine. OHC in outer area was $$4.66 \times 10^{16}$$ J, whereas in the southern part was $$1.47 \times 10^{16}$$ J and was $$1.17 \times 10^{16}$$ J in the northern part of tidewater glaciers fronts.