One way in which the Arctic is not very Mars-like is that there is surface water, and several small lakes and ponds dot the landscape near the hab. One of our studies is looking at the sediment at the bottom of these ponds. The story goes something like this: there are little wormy critters called chironomidae that live in lakes and ponds. In warm years, there are more of them; cold years, fewer. When they die, their little skulls settle on the bottom with the rest of the sediment for that year. So, you can find out about climate change by taking a core of pond gunk, and meticulously counting every chironomid head in each layer using a microscope. It's a bit like tree rings, but with worm skulls.
Here's me gathering a core of pond sediment. Our regular EVA suits don't function well in water, so I'm working the nautical look: