This is post 1/3 in a series on our experiences and tasks as ArcTrain PhD students during the research cruise M164 (GPF 19-1-105) in summer 2020 in the subpolar North Atlantic. Click here to see part 2/3 and here to see part 3/3.
The lines are loosened. The gangway is lifted. The research vessel Meteor moves slowly away from the pier in the Emden port. Aboard are 32 crew members and 16 scientists, including us, 2 PhD students from the International Research Training Group ArcTrain. We pass cruise ships that are tied up on land, the presently prevailing COVID19 pandemic takes its toll on them. From a distance we see the research vessel Maria S. Merian and the two ships greet each other with a few tones of the ship’s horns. We leave the port area and finally reach the river Ems and a little later the German Bight. After changes of the cruise length, start date, end date, ports of departure and arrival, and the research vessel itself, everyone is happy to be on board now. Our unexpected journey begins.
Even under normal conditions, planning a research cruise requires a lot of time and resource management. But in 2020 everything was different. Due to the COVID-19 pandemic the German research fleet operated only from and to German ports. Thus, our research cruise started and ended in Emden, Germany, not as originally planned in Brest, France and St. John’s, Canada. Shortly before the cruise, all participants had to go into quarantine in a nearby hotel for several days. There, we were tested for the Corona-virus individually. After getting the positive news that everybody was tested negatively, we were allowed to embark the vessel on June 21st and left the port on June 23rd.
Our research cruise (M164 GPF 19-1-105) was six weeks long and took us there and back again across the North Atlantic along the approximate latitude of 47°N. The cruise was part of the RACE-Synthesis project following the goal to understand and describe the variability in the subpolar North Atlantic. For this purpose we measured different physical parameters of the ocean, as for example temperature and salinity. With these two parameters oceanographers are able to calculate the density of the ocean water and to estimate volume transports of ocean currents and how they have changed over time. The most prominent current that we measured is the northern extension of the Gulf Stream, the so-called North Atlantic Current. The knowledge about the development of these ocean currents is crucial to understand the dynamics of the North Atlantic and its influences on the European climate. These findings will be incorporated for example in climate models to increase the accuracy of future climate projections. Therefore, observing oceanic parameters out in the field is one of the bottom bricks of climate research.
The water sampler system is back on deck after a dive to 4000 meters depth. This way vertical profiles of physical properties of the ocean are measured (Credit: K. Wiegand). After the deep-sea mooring has surfaced, its orange floating elements can be spotted at the water surface to be recovered (Credit: S. Wett).
During the research cruise we successfully recovered and deployed different autonomously measuring devices, including deep-sea moorings equipped with various sensors, and freely drifting floats contributing to the global Argo program. In addition, we carried out 126 casts delivering vertical profiles of hydrographic properties and ocean velocities. Separate blog posts on the different tasks as ArcTrain PhD students during this research cruise will follow.
Beside the scientific program, the North Atlantic showed its gentle face most of the time, offering us calm weather conditions and lots of beautiful sunrises and sunsets as well as different beautiful oceanic wildlife, including dolphins, whales, Portuguese man-o’-war, sunfish, and several seabirds.
TO BE CONTINUED
Oceanographic equipment at the ship’s stern after sunset (Credit: K. Wiegand). View through a fairlead (hole for ropes) at sunset (Credit: K. Wiegand). A sunfish inspecting a Portuguese man o’ war (Credit: D. Kieke). Clouds and waves just before sunset (Credit: S. Wett).