November 26, 2019
Postcards from a frozen icebreaker – Part 13
Posted by larryohanlon
By Matthew Shupe
11/14/19 Bear Strikes Back
Back on the 9th we had a bear around camp. He was chased away with snow machines and flares. And headed off to the north…. But then in the following day, just after we performed the major power system transplant on our L1 site, our L2 site failed. I examined all of the available information, and it told me a story: The inclination of the system changed abruptly by an angle that was ~3 times larger than the change from when Dave and I climbed on a station together; at about this same time the sonic anemometer instrument quit. The rest of the system’s communications went out about 8 minutes later, just after a couple spikes in one of the shortwave radiation sensors. I speculated that this was a bear because the force exerted on the system must have been about 3 times that of Dave and I, and the fact that things were operating fine before and parts failed over the course of multiple minutes instead of all at once. With our brief visit by helicopter today, it appears that this speculation is true. It looks like the bear walked around the station and first yanked on a cable to the sonic anemometer, shattering a metal connector. He then jerked on a few other cables, totally pulling them apart and breaking another connector that was inside our main box. He pulled on our met mount, up at 2m height so he must have been standing on hind legs; this bent it down to one side. And then he found the good stuff: the exhaust from the fuel cell power system is water. (As an aside, I wonder how bears drink water at all? I guess they must melt snow). It looked like he was sucking on the exhaust, pulled it out and chewed on a heat cable, mangling the copper outlet tube. This last part may be the hardest to fix as we have spares of all the instruments and cables, but will need to figure out a solution. All-in-all, it appears that, after another major field surgery, we should be able to resuscitate this system and get it operational again.
11/17/19 Cracked Up, Revisited
It started small, as they all do. About 1m across at the point where the spine road leads past Ocean City out towards Met City. The crack meandered and there were places to easily just step across. No major changes over the day. We went on with our daily work at Met City….. In the afternoon a couple of us went out to do some powerline maintenance. As it was there was little slack in our power network to accommodate cracks, so we disconnected some of the powerline straps and pulled available slack to the area around the crack. Loops of heavy power cable sitting near the edge. I estimated that it could absorb a widening to perhaps 20m. It held out well beyond that, but in the end it still wasn’t enough. Saturday evening the crack opened to ~20m in places, then made a lateral shift of as much as 100m. Met City, Remote Sensing site, and the ROV Oasis all moving more forward towards the centerline of the Polarstern from the starboard side. A bit reminiscent of the bid lead we had 22 years ago at SHEBA; that one moved our camp 500m to the side and made it necessary to power the camp on generators for the rest of the project….. But here, at MOSAiC, with this big shift, somehow Met City survives. It appears to be crack free, all instruments standing, and amazingly the power is still on! By Sunday morning there was a shear in the other direction, back beyond the original connection point…. Opening, closing…. And finally coming to a rest at nearly the original starting point. Met City power was finally interrupted at about 7am local time, its characteristic green light going out. Sunday was a planned day off so no science activities on the ice…. But the logistics team was still busy; They work very hard in support of this mission. By the end of Sunday, Met City is still standing but dark, and the 30m mast has an odd tilt to it. Will have to explore that tomorrow.
Read more of Shupe’s posts 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, which is frozen into an ice floe where it will drift until September 2020. 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 during the first several weeks of the expedition, led by the Alfred Wegener Institute. Shupe is aboard AWI’s Polarstern until late December; he’ll return to the ship for at least one more two-month stint next year. 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.