About old stones, Arctic weather, farewell to the Arctic and Heinz Rühmann

Despite this success, however, a wistful feeling remains. Originally our “Polarstern” Expedition has been planned to be carried out as part of the IODP drilling campaign. Finally the already scheduled IODP campaign has been cancelled as the additional money for hiring a Russian powerful icebreaker needed to break the ice under worst conditions, has not been available. This year, however, we did not find any ice at all the potential drill sites (Fig. 1), i.e., the drilling campaign could have been carried out without any additional icebreaker support. What a pity that we did not have known this in advance …..! Let’s hope and cross our fingers that the IODP drilling compaigh will become reality before the end of the running IODP phase.

Thursday (04 Oct 18). The last geo-station, a gravity corer goes to water very early in the morning. That’s it, the end of the geology sampling and coring program. At 08:30 then the ultimate station of our expedition: a final drift buoy is deployed via mummy chair. This becomes a very short station. The buoy has just been put on the ice floe when a polar bear mom and her kid show up, coming very close to the ship and the buoy. Some movement or noise on the ship has scared the polar bears, and we continued our voyage towards the west. Thus, we do not know whether our two polar bears will come back to the buoy, play with the buoy ….. At 10:00, we stop all scientific research instruments and registration systems – this is the end of our research program!

The weekend, a special weekend (you will see later), is coming closer, introduced by pancake ice and thick fog, simply dull weather conditions! “Weather” is the key word – up to now another minor program dealing with meteorological measurements, has not been introduced so far. Dirk, this is now your chance – go ahead!

During our cruise in the Arctic waters, Dirk Olonscheck from the Max Planck Institute for Meteorology (MPI-M) performs atmospheric measurements in collaboration with Christian Rohleder and „Weather-Max“ from the German Weather Service (DWD). The main part of this work is the launching of radiosondes attached to a weather balloon. While the DWD launches one radiosonde per day at 12 a‘clock UTC, Dirk complements this base activity by launching three additional radiosondes per day every six hours (Fig. 3). This is part of the special observing period of the Year Of Polar Prediction (YOPP). Radiosoundings have a long tradition also in polar research. At the Third German Expedition to Antarctica in 1938/39, radiosondes were described the following: "The shining device is a tiny radio station, strong enough to be heard from a distance of 60 km. And due to a clever setup, this instrument of only about 1 kg of weight – including the battery – is constantly sending temperature, air pressure and relative humidity. Together with the wind data, the sum of the meteorological measurements provides everything that one can demand about the weather conditions. And this is from the sea level to more than 20 000 m height, i.e. far into the stratosphere." (*, translated from German)

Our radiosondes on board “Polarstern” only weight 100 g and the balloon is carrying them to a height of more than 35 000 m. However, for more than 80 years, the basic principle is the same! The collected data on the temperature, humidity and wind profiles of the atmosphere hopefully contributes to substantially improve the weather forecast here in the northern high latitudes, and are also used directly on board to judge the safety of our helicopter activities. As in earlier times, „the daily radiosounding belongs to breakfast, like brushing the teeth beforehand“ (*), but still many launches have plenty of visitors from both the scientists and the crew.

* Source: Ernst Herrmann (1941), "Deutsche Forscher im Südpolarmeer, Bericht von der Deutschen Antarktischen Expedition 1938-1939", Safari-Verlag Berlin

The especially curious ArcTrain students Amélie Desmarais and Samira Samini join the launches from early on. They get to know the procedure and were a valuable help for launching so many weather balloons in the last weeks. Many thanks to Amélie and Samira!

Saturday (06 Oct 18). 07:00 on the bridge,  the captain changes the course to 290, we are steaming through ice-free waters towards WNW. At 09:41 we pass 83°05.1’ N, 56° 24.4’ E! Actually nothing special, or? If you remember what has happened on September 23, you would say “yes, an important step”!! On September we have documented (see 3rd Weekly Report) that with 83°05’ N we have reached the northernmost location of our entire expedition. This statement has to be withdrawn now! And we continue towards WNW: at noon we reach 83° 12.5’ N! Where does this end? – although most of the people have not realized the change of our course and certainly do not know why! Meanwhile small pancake ice floes are passing the ship, becoming closer and bigger (Fig. 5, upper left). Slowly the penny dropped!! We are approaching the ice edge, we reach the ice edge at 18:00 – exactly in time with the beginning of our barbecue. And this is now really the northernmost position of our expedition: 83° 38.7’ N, 44° 08.3’ E!!  But this is not all – a few minutes later two polar bears on an ice floe (mom and kid, maybe the same we have seen three days ago?), followed by a – for Arctic conditions – already quite big iceberg, drifted along on starboard side. This is really a perfect staging by our captain that would fit into any movie. Congratulations and thanks a lot!! This makes our expedition to an unforgettable adventure to all the participants, especially the tyros. We have now some hours to enjoy this scenery and the farewell barbecue & dancing party, and say “good-bye” to the Arctic.