A Meteoric Water Budget for the Arctic Ocean

A budget of meteoric water (MW=river runoff, net precipitation minus evaporation, and glacial meltwater) over four regions of the Arctic Ocean is constructed using a simple box model, regional precipitation-evaporation estimates from reanalysis data sets, and estimates of import and export fluxes derived from the literature with a focus on the 2003-2008 period. The budget indicates an approximate/slightly positive balance between MW imports and exports (i.e., no change in storage); thus, the observed total freshwater increase observed during this time period likely resulted primarily from changes in non-MW freshwater components (i.e., increases in sea ice melt or Pacific water and/or a decrease in ice export). Further, our analysis indicates that the MW increase observed in the Canada Basin resulted from a spatial redistribution of MW over the Arctic Ocean. Mean residence times for MW were estimated for the Western Arctic (5-7 years), Eastern Arctic (3-4 years), and Lincoln Sea (1-2 years). The MW content over the Siberian shelves was estimated (similar to 14,000 km(3)) based on a residence time of 3.5 years. The MW content over the entire Arctic Ocean was estimated to be >= 44,000 km(3). The MW export through Fram Strait consisted mostly of water from the Eastern Arctic (3,237 +/- 1,370 km(3)yr(-1)) whereas the export through the Canadian Archipelago was nearly equally derived from both the Western Arctic (1,182 +/- 534 km(3)yr(-1)) and Lincoln Sea (972 +/- 391 km(3)yr(-1)).