We studied the temporal variations of CO 2 , O 2 , and dimethylsulfide (DMS) concentrations within three environments (sea‐ice brine, platelet ice‐like layer, and underlying water) in the coastal area of Adeélie Land, Antarctica, during spring 1999 before ice breakup. Temporal changes were different among the three environments, while similar temporal trends were observed within each environment at all stations. The underlying...