The scientists that I worked with were actually measuring various chemicals in the air that come from pollution. They are trying to understand how those chemicals move in between the ocean air, snow, sea-ice, and snowpack. Once they learn more about them, they can find out how they will change as the climate changes.
We were sampling snow in the Arctic for nitric oxide compounds. NOx's. A lot of these come from car exhaust in places much further south like LA, or Florida, and travel a very long way to the Arctic. They come out of the atmosphere in the snow and rain. Some other chemicals like mercury from coal fired power plants make it to the Arctic, come out of the air the same way, and then end concentrated in the food supply of the native people.
It is important to get an understanding of these chemicals and their concentrations, so that you can understand how they might change. They are not affecting the temperatures like Carbon Dioxide does, but they do affect the environment in other ways.
Thanks for the great question. If you want to keep reading my blog, I will be putting new things out there from a recent trip to Canadian Arctic and Greenland where we saw many many polar bears and lots of other wildlife.