Figure 7.4 Schematic representation of the high-latitude freshwater system as introduced by Prowse et al. (2015a). Moisture is transported from the subtropical and tropical Atlantic Ocean to the Pacific Ocean via the Trade Winds over Central America (thick grey arrow). The sub-Arctic front separates the thermally stratified sub-Arctic oceans (darker blue) from the salt-stratified northern ocean (lighter blue) in both the Atlantic and Pacific Oceans. Moisture is transported from the Pacific and Atlantic Oceans to the Arctic catchment basins by the mid-latitude (Westerlies) storm tracks (thick blue arrows), and subsequently drains into the Arctic Ocean (thick white arrows) where it spreads initially within the Riverine Coastal Domain (dashed green arrows). Warm, salty Atlantic-origin waters (thin red arrows) enter the Arctic Ocean through Fram Strait (the Fram Strait Branch) and the Barents Sea Opening (the Barents Sea Branch) and circulate within the Arctic Basins as subsurface, cyclonic, topographically steered boundary currents along the continental margin and ridge system. Internally modified Atlantic waters exit the Arctic Ocean southward through Fram Strait along eastern Greenland. Cooler and fresher Pacific-origin waters (thin blue arrows) enter the Arctic Ocean through Bering Strait and exit through the Canadian Arctic Archipelago and Fram Strait along eastern Greenland. Within the Arctic Ocean a topological distinction is made between inflow, interior, and outflow shelves (cf. Carmack and Wassmann, 2006; Bluhm et al., 2015).