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.
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.