Our site on the sea ice is first year, meaning that it is newly formed this year, and will likely melt in summer. It is usually 0.5-1.5 m thick. Multi year ice persists for years and is usually thicker (3-5 m). It is also a landfast site, meaning that the sea ice is still attached to the coast (as opposed to free floating ice).
Here is David, one of the researchers from CRREL (Cold Regions Research Engineering Laboratory) walking on the sea ice. They are laying out transects of flags on the ice so that twin otter planes with remote sensing equipment such as LIDAR can fly over.
Here are the sleds full of our gear. The plan is to measure the thickness of sea ice on the ground, and then to mark the site so that the planes can fly over and use remote sensing to gauge the thickness of sea ice. Scientists use this kind of ground truthing to help correct the remote sensing data from flyovers often used to assess the thickness of sea ice in the Arctic.
As you can see, sea ice can deform and make piles. This means that measuring the thickness remotely is not necessarily straightforward.
And here are the researchers drilling a core from the sea ice. Holes are drilled into the ice at intervals to measure temperature and salinity, to create a profile of the ice characteristics with depth.
We have laid the core onto this measuring board. You can see the snow on top, transitioning into ice at about 20 cm, and then towards the bottom of the core the ice looks dirtier. This is perhaps due to the presence of ice algae that live in the bottom of sea ice. We will melt and filter the sea ice in Barrow, and then return to Ann Arbor to conduct a full geochemical analysis of the ice. We hope to learn about the concentration and provenance of dust in the sea ice here.
Meghan Taylor here! I am in Barrow, AK this week to obtain cores of sea ice on the Chukchi Sea, offshore from town. We start at the UMIAQ hangar to pick up our snow machines. UMIAQ is the native corporation that manages permitting and logistics for scientists working on the sea ice. They also provide us with an armed guard who stands watch for polar bears. His name is Mike and he likes to play reggae music from a radio in his coat while we work. There is thick ice fog on the shore to day and everything is hazy. The ice fog was dense and close to the ground so that you could still see that it was a bright, sunny morning 40ft above you. Here we are filling a couple of sleds with gear needed for today’s field work. This is me, geared up for a ride on the snow machines. Our site is about 7 miles away, which is a 30 minute ride on the skidoos. We cover up because we are riding in temps around 1˚F, and you don’t want any skin exposed! Here you can see the edge of the sea ice. This lead was solid sea ice just a few days before, and has just opened up. There are faded prints, barely visible, of polar bear tracks here. Our bear guard thinks that they are a day or two old, where a polar bear pulled itself out of the ocean and walked towards shore. Now that the ice is breaking up, bears will become more common near town, but Mike says that their presence is more noticeable after the whale season starts and the the first whale of the season is taken. Me again, and another researcher, Andre. He will not let me drive! It is nearly 8:30 pm here and still fairly bright and sunny. It does not become truly dark until after 9:30 pm in early spring. Long daylight hours are conducive to a long day on the ice: I had no idea of the time until someone starting passing out cookies and I realized it was well after dinner. Next time I’ll post some pictures of the really nice ice core we got, and some of the other field work going on out here.