Now it is time to move southward to our first BioGeo-station, where 10 different types of sampling are supposed to keep us busy for one day (Photo 4). It is a challenge to organize such station because sampling has to be done in blocks, limited and separated in time. The start is bumpy but with a high gain of experience. At the end, it is the approach of a strong low-pressure system, which stops our station work and forces us to escape to the northern sea ice where the sea is much calmer. However, we will return, since we leave back two landers, autonomous instruments measuring various parameters close to the sea floor, and one drifting trap.
We made the right decision to move towards the center of the cyclone, because slightly weaker winds cleared the area from sea ice such that we are able to deploy the second mooring in the morning of 13 February. Instruments from AWI as well as from our colleagues from Sweden and Norway will measure for several years temperature, salinity, and currents of a 2000-m thick water column. Since we are done at lunch time, we can slowly approach the two Norwegian moorings to the south, which will be recovered the next day and deployed again, when we leave the area beginning of March. On the way southward, we run several CTD (conductivity, temperature, and depth) casts across the slope front, separating the cold (-1.9 °C) waters of the continental shelf from the relatively warm (+ 0.75 °C) waters of the open ocean.
Needless to say that on 14 February the recovery of both moorings happens faster than calculated. Therefore, we can steam southward searching for the drifting trap, which sent its last position via telephone link to be 20 nm south of its deployment site. While writing this report, the little runaway safely gets on board again.
PS124 sends regards from a calming Weddell Sea –a popular ground for Polarstern visits for more than 35 years.
Hartmut H. Hellmer (Chief Scientist)