Archive of News and Press Releases

PS111 – Weekly Report No. 1 | 19 - 26 January 2018

Temperature Changes

[30. January 2018] We just escaped from the snowstorm in Germany. Since our plane had to be de-iced and then re-fueled twice, we started our flight to South Africa with a 3-hour delay. Between the Bavarian slush and the Antarctic sea ice, we enjoy a short warm-up period with wonderful 26 °C while having a ‘farewell beer’ at Cape Town’s Waterfront.

Polarstern leaves port early, because increasing Cape Winds might cause the port to close – which actually happened two hours after we left. During the afternoon of 19 January, we start crossing the latitudes, with their furious names and bumpy seas – and within a few days we are back to German winter temperatures.

Fig. 1: Cape Town‘s Table Mountain says goodbye with a splendid ‘icing’ on its top. (Photo: Alfred-Wegener-Institut)

Fig. 2: AWI’s curious administrative director, Karsten Wurr, is impressed by the variety of scientific instruments and sampling devices on board. Here, the Autonomous Underwater Vehicle (AUV) of our British colleagues is prepared for its mission in the (Photo: Alfred-Wegener-Institut)

Fig. 3: Humpback whale watching the progress of a CTD cast. (Photo: Alfred-Wegener-Institut)

Our life on board starts with an introduction to the ship, the safety regulations, and common procedures like the schedule for meals, the change of linen, etc. A high-pressure ridge calms the Roaring Forties, making it easier for us to unpack our instruments. Countless boxes are pulled to the labs – we have 360 tons of scientific gear and other equipment on board, stored in within the 41 containers that are onboard. Many of those containers stay untouched as they contain the supplies for the Neumayer III station on Ekstrom Ice shelf. Fifty-three scientists start setting-up their labs, supported by the professionals – the 43 crew members.

Already in the Furious Forties, the first instruments go over board: Argo floats, which are autonomous oceanographic instruments, profiling the ocean for temperature and salinity from a depth of 2000 m up to the surface, from where the data are transmitted via satellite to the data storage facility ‘Coriolis’ until their batteries die. A new under-way CTD (conductivity, temperature, depth) is towed behind the ship to measure temperature and salinity of the upper 600 m as we cross the many fronts of the Antarctic Circumpolar Current (ACC). And the geologists prepare the pipes to get the first sediments from the ocean floor.

A big hole in the sea ice cover, larger than 100 m in diameter, is called by the Russian name ‘polynya’. Most polynyas are caused by katabatic winds coming from the ice sheet and blowing the sea ice away from the ice shelf fronts. However, there is an exception: The Maud Rise Polynya, in the middle of the ocean, very unique and, when it appeared in the winters of the mid 1970’s, bigger than 80 000 square kilometres. After an absence of more than 40 years, the polynya showed up again, smaller than before, but still exposing 40 000 square kilometres of open water to the winter atmosphere. Now it is austral summer and the sea ice has retreated to its minimum. However, as we cross the area of last winter’s phenomenon, we stop to check whether the fingerprints of strong winter convection can still be detected in the deep water column.

In the early morning of 27 January, the close visit of a family of Humpback whales, showing their offspring what a research vessel looks like from all sides, changes priorities. Not just does the coffee get cold in our cups, but also all the sonars go quiet to enjoy the encounter.

PS111 sends kind regards from Maud Rise, the ‘Home-Hill’ in front of Atka Bay.

Kind Regards to all at home

Michael Schröder

Chief Scientist