the 22nd Pacific−Asian Marginal Seas meeting (PAMS)

Surface-bottom turbulent silicate (Si) flux was estimated with micro-temperature measurements and bottle sampled Si-concentration along the dateline and 47°N across the subarctic North Pacific and the Bering Sea. The silicic acid (dissolved Si; dSi) flux took the vertical maxima along the North Pacific Intermediate Water neutral density surface at around neutral density of 26.9γN corresponding to the vertical gradient maxima of dSi concentration. The flux was large through the water column from ~2000m to the near-surface at around the Amchitka Pass where the silica flux exceeding 10^-1mmol m^-2 d^-1 was observed corresponding to the large turbulent diffusivity. This large flux well corresponds to horizontal silica maxima along the Aleutian Passes at isopycnal surfaces of <27.6γN and near the surface <200m. This dSi supply suggests enhancement of the diatom production along the Aleutian North Slope Current and the Bering Slope Current in the Bering Sea, contributing to the silica-rich Bering Sea and the North Pacific. The silica supply is probably due to the dissolution of sinking diatom particles from surface and from bottom sediment.
 

Bering,Turbulence,silica,Marine biogeochemistry,physical oceanography