The near surface hydrography beneath the Odden ice tongue

As part of the European Subpolar Ocean Programme (ESOP), the German researc h icebreaker Polarstern worked in the Greenland Sea in the late winter of 1 993. Whilst on passage, the ship encountered a severe winter storm with win ds consistently above 20 m s(-1) coupled to air temperatures of below - 10 degrees C. The underway sensors revealed heat fluxes of greater than 700 W m(-2) across most of the Nordic Basin, peaking at greater than 1200 W m(-2) when the ship crossed the cold, fresh water of the Jan Mayen Current. This large heat flux coupled to the unique hydrographic conditions present in t he Jan Mayen Current allowed sea-ice generation in the form of frazil ice a t a rate of 28 cm d(-1). This frazil ice then developed into pancake ice. M easurements also were made in the late winter beneath this pancake ice in t wo remnants of the Odden. In the Jan Mayen Current, hydrographic conditions are such that the ice can exist for a long period of time before eventuall y decaying due to short-wave radiation at the surface. Towards the centre o f the Greenland Sea, hydrographic measurements reveal that the ice is more transient and decays four times more rapidly than ice in the Jan Mayen Curr ent. We discuss the development of the Odden ice tongue in light of these r esults and add evidence to the argument that the eventual fate of the water stored in the ice is important and could be a relevant factor in the forma tion of Greenland Sea Deep Water. (C) 1999 Elsevier Science Ltd. All rights reserved.