Towards recognition of physical and geochemical change in Subarctic and Arctic Seas

The advection of parent subarctic water masses, and their subsequent modification upon entering the Arctic Ocean and during transit of the pan-arctic system, has fundamental impacts on ice cover, ocean properties and ecosystem dynamics. The Canadian IPY project Canada’s Three Oceans (C3O), together with the international Joint Ocean Ice Study (JOIS), collected physical, chemical and biological information in 2007 and 2008 against which changes in the subarctic and arctic waters surrounding northern North America can be quantified. This paper presents physical and chemical data from 2007 to describe oceanic domains around northern North America, and offers conceptual frameworks against which linkages between the subarctic and arctic domains can be categorized. Ongoing changes include ocean warming, sea-ice melting, upper layer freshening, altered stratification, increased acidification and, in the subarctic Pacific, increased hypoxia.