July 20, 2020
By Matthew Shupe
6/27/20 A towering tower
Our big event today was raising the met tower. After a couple days of installation and sorting out a few instrument issues, we then ran the tower in the down position for another day to intercompare the different instruments while they all sat at the same level. But with all of that preparation finished, we were then ready for the big event. This is one of those events that people talk about; we had a large group of people with us, including the 4-person communications team to be sure and document every move. I admit a certain degree of nervousness. We’ve lifted the tower a few times now and I’m not too concerned about that process. We combine human power, by just lifting and walking the tower into place, with a come-along system at our primary anchor. The problem is that we couldn’t really get an anchor in at the primary anchor point. The ice around the ridge is 5+ meters thick, such that I’m guessing the ridge itself is likely more than 7m thick. So no anchor at that position.
Byron had the great idea that we should just anchor the tower to the new Met Hut (formerly the Remote Sensing hut). It is a bit far away, messing up the ideal geometry for tower guy lines…. But close enough. And the building weighs 700+ kg, plus the new equipment inside and all of its friction on the surface. So it is now serving as our primary anchor. As with on Leg 1, we had a big team, 6 of us. One on the guide rope, one on the pusher pole, 3 lifting the tower itself, and me on the come-along. A brief safety discussion, and then away we go. Crank, crank, crank on the come-along; push, push, push on the steadily elevating structure. Pretty smooth again with no major glitches. Took a couple of minutes of hard work and we now have a vertical met tower standing proud out on the ridge extending out from Polarstern into the middle of the MOSAiC floe. High above the ponds and hummocks extending beyond.
Our flux sleds have turned out to be great scientific tools. The measurements themselves have been super reliable. Consistent and steady. No icing. The primary issues have been mitigation of icing on the exhaust for the fuel cell…. And ice dynamics. We can work to improve the systems to address the former. But there is not much to be done about the latter. If the ice decides to come together, it will simply destroy anything in its way. That’s what happened to our so-called ASFS50 station. A 1000-pound station flipped upside down by the ice back during Leg 2. Since that time the station has been fixed and operated at times. And we brought out some new parts with us on this leg. So now the system is in prime condition.
Today we pushed it out to its new home out in the First Year Ice domain of our floe, to provide a nice contrast with the met tower, which is set up on the thicker, second year ice. With no skidoo tracks, we opted to instead push the sled into position, about 400m along a windy track through the ice, over small ridges, through melt ponds. In many ways it was like pushing a bobsled through a track. And the sled did awesome! It’s a rigid structure, because we need it to be very stable. Thus, I had some concern with how it would handle the bumps and curves. But this lack of flexibility actually worked out well…. And the skids themselves worked so well. The bottom surface is covered with this special plastic that slides very easily over icy surfaces (thanks to Polarfield Services for the recommendation on that!). Overall Jesse and Tom did an amazing job of designing and building the structure of these sled systems. They’ve been so easy to manage in the field, to push around even with just two people, and support a successful operation out here.
Scientist Matthew Shupe (CIRES/University of Colorado Boulder) is blogging from an icebreaker frozen into Arctic Ocean sea ice, so far north that the Northern Lights are no longer visible. Shupe is co-coordinator of the international Arctic climate mission MOSAiC, or Multidisciplinary Drifting Observatory for the Study of Arctic Climate. Today, he’s among about 100 people aboard the German icebreaker Polarstern. Shupe, who also works for the NOAA Physical Sciences Division in Boulder, Colorado, began planning the mission more than a decade ago, with an expanding network of scientific leaders from around the world. In a series of short posts from the ship, he shares his experience of the expedition, led by the Alfred Wegener Institute. U.S. funding for MOSAiC sciences comes primarily from the National Science Foundation and the Department of Energy. Follow the expedition: https://follow.mosaic-expedition.org/ and @MOSAiCArctic.