Turbulent nitrate fluxes in the Amundsen Gulf during ice‐covered conditions

Turbulence and nitrate measurements collected in the Amundsen Gulf during ice‐covered conditions in fall 2007 are combined to provide mean vertical profiles of eddy diffusivity and diffusive nitrate fluxes . The mean diffusivity (with 95% confidence intervals) was maximum near the uppermost sampling depth (10 m) with max = 3(2, 5) × 10 −3 m 2 s −1 and decreased exponentially to a depth of ∼50 m, below which it was roughly constant at the background value b = 3(2, 5) × 10 −6 m 2 s −1 . The nitracline, centered around 62 m depth, was subject to an eddy diffusivity close to the background value b and the mean diffusive nitrate flux across the nitracline was nit = 0.12(0.075, 0.20) mmol m −2 d −1 . These observations are compared with other regions and the role of vertical mixing on primary production in the Amundsen Gulf is discussed.