Pacific ventilation of the Artic Ocean's lower halocline by upwelling and diapycnal mixing over the continental margin

• Main Authors: Woodgate, Rebecca A., Aagaard, Knut, Swift, James H., Falkner, Kelly, Smethie, William M.
• Format: Article in Journal/Newspaper
• Language: English; unknown
• Published: American Geophysical Union
• Subjects: Arctic Ocean; Chukchi
• Online Access: https://ir.library.oregonstate.edu/concern/articles/zw12z673q

Pacific winter waters, a major source of nutrients and buoyancy to the Arctic Ocean, are thought to ventilate the Arctic's lower halocline either by injection (isopycnal or penetrative) of cold saline shelf waters, or by cooling and freshening Atlantic waters upwelled onto the shelf. Although ventilation at salinity (S) > 34 psu has previously been attributed to hypersaline polynya waters, temperature, salinity, nutrient and tracer data suggest instead that much of the western Arctic's lower halocline is in fact influenced by a diapycnal mixing of Pacific winter waters (with S ~ 33.1 psu) and denser eastern Arctic halocline (Atlantic) waters, the mixing taking place possibly over the northern Chukchi shelf/slope. Estimates from observational data confirm that sufficient quantities of Atlantic water may be upwelled to mix with the inflowing Pacific waters, with volumes implying the halocline over the Chukchi Borderland region may be renewed on timescales of order a year. Keywords: Pacific ventilation, Arctic Ocean, diapycnal mixing Keywords: Pacific ventilation, Arctic Ocean, diapycnal mixing