by Matthew Shupe, CIRES/NOAA scientist and co-coordinator of MOSAiC
As of today, Met City is no more. Our largest installation on the ice, reduced to rubble. Fortunately, most equipment installed on the surface had already been removed. Brought back to the ship for its 3-week journey to the ice edge and back. Those instruments will all live to make more measurements. The same cannot be said for our ice and ocean buoy measurements at the site. Two days ago, after lots of discussion about feasibility and the delay it would cause, the decision was made to try and recover buoys installed at Met City. Of particular focus was the Ocean Flux Buoy, which was now right on the edge of a small chunk of ice. Nearly broken free already, such that it might be as simple as pulling alongside with the ship and hoisting the system onboard with a crane. Those ocean heat flux measurements are so important for tracking the overall thermodynamic and dynamic state of the ice. They pair with our equivalent atmosphere-ice measurements on the top surface of the ice. The melt season will be upon us shortly and we need to track the shifts in energy transfer that signify, and drive, this transition. With Met City in a precarious, and degrading, position we decided that the ocean flux buoy would likely be destroyed soon anyway, so a rescue was planned. No sure thing, but having that system onboard would at least give us the potential for later redeployment along with other instruments. The recovery was planned for today, with the potential to explore extraction of other systems as well. But alas, over “night” as with so many other times recently, the ice has had something else in mind. What was once a loose and open collection of small ice chucks was not coming together with great pressure. Squeezing those assets left in the ice. Our on-site expeditioners travelled out from the ship on foot, a voyage made much easier now that the ice was pushed back together. They found what remained of the Met Hut….. crushed by the ice, pushed in on top of itself. Destroyed. And over by the buoys….. nothing. No trace of the flux buoy or four other systems that had been in the area. They simply vanished. Likely pulled under by rafting ice. So after 7 months of MOSAiC, we’ve lost Met City. Nothing left except a few torn walls of the hut, jutting up out of a rubble field of ice blocks. Perhaps a short break in the expedition is good right now, to regain our bearings and adapt our strategy.