During the last week of our expedition we made good overall progress.

The four moorings in the central Greenland Sea, equipped with autonomous profiling CTDs, were successfully recovered and deployed again. Because of excellent weather conditions we were able to perform this work in the twinkling of an eye. In the course of our cruise towards the Greenland coast we continued with hydrographical measurements. The sea ice coverage was surprisingly far expanded towards the East - way further than predicted by satellite images. However, the sea ice was patchy and not a serious obstruction for R/V Polarstern at all. Unusual was also the subjectively estimated high proportion of one-year-old floes in the pack ice belt. These conditions allowed us to continue our hydrographical work very close to Greenland’s coast.

Unfortunately for all of us but especially for the marine mammal and bird observers onboard we encountered a weather situation characterized by persistent fog. The poor visibility prohibited visual sightings as well as working with the highly sophisticated infrared camera system which was installed during the last stay of R/V Polarstern in the dockyard in Bremerhaven in June. The infrared camera system was developed to autonomously detect the presence of whales in the vicinity of our research vessel. The hardware as well as the software is already working operationally which is remarkable considering the systems’ high degree of complexity.

The weather conditions didn’t affect the research on improving the data basis needed to reliably reconstruct the climate of the past. Work at sea concentrates on taking and processing sea water samples. Compared to the comprehensive analytics later in the lab, the work at sea is uncomplicated. However, filtering the sea water samples and preparing the resulting filters for the transport is time consuming. Also our research on the Arctic ecosystem which concentrates on the interrelation between the biological productivity and environmental conditions is not weather dependent. The necessary water samples from the ocean are collected by the physical oceanographers with a rosette water sampler which can hold up to 300 litres sea water.

Our way from the Greenland Sea to the Fram Strait led us for the most part through pack ice and fog. Shortly before we reached our working area at 78°50’N the visibility improved significantly and the noise produced by breaking ice, which can be annoying during night time, became silent. Where other ships navigate carefully through fields of ice, R/V Polarstern is able to cruise almost unaffectedly by breaking or pushing floes. It is obvious that the liaison of steel and ice is not noiseless at all.

In the Fram Strait we will spend most of our time with the recovery and deployment of oceanographic moorings. The Fram Strait is the only deep passage to the central Arctic basin. The numerous oceanographic moorings are installed across the Fram Strait to quantify the exchange of water masses through this passage. The mooring work will keep us busy at least the first part of next week.

With best wishes from all onboard!

Gereon Budéus, Chief Scientist ARK XXIV-1
July 3rd 2009