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 (K) over bar and diffusive nitrate fluxes (F) over bar. The mean diffusivity (with 95% confidence intervals) was maximum near the uppermost sampling depth (10 m) with (K) over bar (max) = 3(2, 5) x 10(-3) m(2) s(-1) and decreased exponentially to a depth of similar to 50 m, below which it was roughly constant at the background value (K) over bar (b) = 3(2, 5) x 10(-6) m(2) s(-1). The nitracline, centered around 62 m depth, was subject to an eddy diffusivity close to the background value (K) over bar (b) and the mean diffusive nitrate flux across the nitracline was (F) over bar (nit) = 0.5(0.3, 0.8) 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. Citation: Bourgault, D., C. Hamel, F. Cyr, J.-E. Tremblay, P. S. Galbraith, D. Dumont, and Y. Gratton (2011), Turbulent nitrate fluxes in the Amundsen Gulf during ice-covered conditions, Geophys. Res. Lett., 38, L15602, doi:10.1029/2011GL047936.