RV Polarstern left the harbour of Bremerhaven precisely in time at 9:30h on 20 June 2009 in order to perform research in the Greenland Sea and in Fram Strait. On the way to those regions we passed Helgoland, where a rendezvous at sea with RV Uthörn was scheduled to celebrate the 50 anniversary of the biological research station on Helgoland, BAH. This was our last sight contact to land for some time. Only close to Norway we entered coastal waters again and disembarked a couple of persons, which had to do technical checks on board, by a helicopter flight to Stavanger.

The first days at sea are self evidently always characterised by numerous start up procedures. Apart from the personal introductions of scientific and board crew, information meetings concerning the life on board, security instructions, unpacking of the scientific freight, lab distribution etc. were on the schedule. Once all science groups got their freight, the installation of the labs began. The comparatively calm sea facilitated this part of our work considerably.

The main focus of our cruise leg is on physical measurements in the ocean. Both the Greenland Sea and the Fram Strait are key regions with respect to ocean climate. The Greenland Sea is one of the few regions worldwide where in winter surface waters can attain densities which are high enough to let them sink to very large depths and ‚ventilate’ the global ocean by this. During the last decade, a complete and unique rearrangement of the basin wide hydrographic structure in the Greenland Sea has been observed. Fram Strait, on the other hand, is the only deep connection of the central Arctic basin with the world ocean, and the complete exchange of deeper waters must pass this area. Of special importance is the heat transport through the strait which varies considerably and is of outstanding importance for the heat balance of the Arctic Ocean. Measurements of physical properties of ocean waters as well as current speed measurements work electrically nowadays almost exclusively. These measurements are performed with outstanding precision from the ship during the expedition but are extended over the entire year by the use of moored instruments.

We could start our work on the first stations on Friday, the exchange of the first moorings is on our time table tomorrow. With great interest we observe already now the ice conditions east of Greenland, as we will enter these waters within a few days. Remote sensing by satellites reveals valuable information about the ice coverage in our times. At places where only a week ago no progress seemed possible at all, the ice seems to have thinned by now to such an amount that we expect a fairly rapid transition through it during our work in the waters east of Greenland.

With best wishes from board,
G. Budéus, Chief Scientist ARK XXIV/1
27 June 2009