Concentration of nutrients and primary production in sea ice of the high-latitudinal Arctic

Dynamics of phosphates and silicates in sea ice of the high-latitudinal Arctic are considered for period from November 2005 to May 2006. It is shown that, during ice formation, silicates are included into it in the same ratio to salinity that is characteristic of under-ice water. Further dynamics of silicates are determined by their bioassimilation with beginning of the polar day and by biogenic silicon accumulation at bottom meltwater pools with subsequent leaching. Phosphates are included into ice in a ratio higher than that occurring in the under-ice water. This is caused by the fact that liquid phase of sea ice represents composition of the surface microlayer at the ice-water interface, which is enriched in organic matter and in products of its destruction (particularly in phosphates). With onset of the polar day, content of phosphates first markedly increases (due to photo oxidation of biogenic organic matter) and then decreases because of bioassimilation. At the beginning of the polar day, primary production of diatoms was estimated to be ~0.3 mg C/m**2/day.