Permalink :  http://hdl.handle.net/2115/91846

JaLCDOI :  10.14943/lowtemsci.82.57

KEYWORDS : 海氷-海洋境界層; 乱流混合; エクマン螺旋; 浮力フラックス; 北極海; Ice-ocean boundary layer; turbulent mixing; Ekman spiral; buoyancy flux; Arctic Ocean

We conducted on-site investigations in the central Arctic Ocean about turbulent mixing and heat and salt transport in the sea ice-ocean boundary layer, related to the growth and melting of sea ice. During these observations, continuous measurements were performed beneath the sea ice while drifting with the icebreaker, RV Polarstern, providing insights into the spatiotemporal structure of water temperature, salinity, and turbulent mixing in the boundary layer associated with the periodic sea ice drift. Using an acoustic Doppler current profiler, the survey clearly captured the Ekman spiral in horizontal currents which rotate clockwise with the depth. The direct measurement of microscale current shear was conducted to estimate the production and dissipation terms of turbulent kinetic energy in the mixed layer. In its upper part, the two terms were well balanced. Meanwhile, in the lower part, the dissipation term significantly exceeded the production term, attributing to the near-inertial internal waves generated by the inertial oscillations of sea ice.

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