Understanding ozone and mercury in the air over the Arctic Ocean (OASIS)

The OOTI sled was deployed during several IPY projects in the spring and summer of 2008-2009. The O-buoy program is operational and growing, measuring atmospheric components on the frozen Hudson Bay, the Beaufort Sea and the Arctic Ocean. Results have confirmed speculations on the large scale of the disappearance of ozone and mercury - depletion episodes in the spring were observed everywhere, were severe, and often lasted several days or weeks - and yielded spectacular information on the processes that are involved.

Direct ozone loss to frozen surfaces was usually slow, but mercury was found to deplete and emit around the snow pack. There are indications that these processes may be different over frost flower-covered ice. During some studies it was observed that the disappearances only occurred when the air temperature was below ~ -20 C. This may turn out to be a crucial observation towards understanding how the depletion processes actually operate.