Glossary

Every summer, the snow cover on Arctic sea ice melts completely, leaving behind ponds of meltwater. Accordingly, the water in them is (mostly) freshwater. In large parts of the Arctic, the ponds form within a number of days in early June and only disappear when surface freezing begins in September. Depending on the surface structure of the sea ice, various pond formations can arise, with most ponds having a diameter of a few metres. But on young, smooth ice, they often form entire lake “regions” in which it is difficult to identify individual ponds, given their high degree of interconnectedness.