NASA Firn Cover expedition

Greenland Ice Sheet

by L. Colgan

I am participating in the annual NASA Firn Cover expedition to the Greenland Ice Sheet, which is led by the University of Colorado. We spend about five weeks on the ice sheet, snowmobiling and flying around to sample the “firn” of the ice sheet. The “firn” is the porous near-surface layer of the ice sheet, it is about a 60 m thick layer in which snow transitions into ice. We take cores through this layer as well as maintain automated stations that measure how fast the firn is compacting. Generally, firn is compacting faster in a warmer climate, and if you don’t correct satellite observations of ice sheet volume for this effect, it could appear as though the ice sheet is getting smaller (when in fact the near-surface layers of the ice sheet are just getting denser). We arrived on the ice sheet by C-130 military aircraft at a former DEW-line site that the military still uses called Dye-2, or Camp Raven. We then snowmobiled about 600 km to service five stations roughly along the Arctic Circle. After out snowmobile traverse we serviced more northern sites (up to 76°N) by Twin Otter from Summit Station. Summit Station is at 3200 m elevation, so you notice the shortness of breath coming from Ontario. Less an issue for my Colorado colleagues. We have had our share of weather days, sitting out storms that blow a consistent 40 knots, but we are generally in good spirits and enjoying good meals. I have tweeted a couple images to Lassonde students encouraging them to take my ESSE2210 course this spring semester, and learn a little more about climate change.