Turbulent mixing above the Atlantic Water around the Chukchi Borderland in 2014

Abstract

This study presents an analysis of the CTD data and the turbulent microstructure data collected in 2014, the turbulent mixing environment above the Atlantic Water (AW) around the Chukchi Borderland region is studied. Surface wind becomes more efficient in driving the upper ocean movement along with the rapid decline of sea ice, thus results in a more restless interior of the Arctic Ocean. The turbulent dissipation rate is in the range of 4.60×10–10–3.31×10–9 W/kg with a mean value of 1.33×10–9 W/kg, while the diapycnal diffusivity is in the range of 1.45×10–6–1.46×10–5 m2/s with a mean value of 4.84×10–6 m2/s in 200–300 m (above the AW). After investigating on the traditional factors (i.e., wind, topography and tides) that may contribute to the turbulent dissipation rate, the results show that the tidal kinetic energy plays a dominating role in the vertical mixing above the AW. Besides, the swing of the Beaufort Gyre (BG) has an impact on the vertical shear of the geostrophic current and may contribute to the regional difference of turbulent mixing. The parameterized method for the double-diffusive convection flux above the AW is validated by the direct turbulent microstructure results.