Stable isotope ratios in seawater nitrate reflect the influence of Pacific water along the northwest Atlantic margin

Abstract. The flow of Pacific water to the North Atlantic exerts a globally significant control on nutrient balances between two ocean basins and strongly influences biological productivity in northwest Atlantic. Nutrient ratios nitrate (NO3-) versus phosphate (PO43-) have previously been used complement salinity characteristics tracing distribution We expand this premise demonstrate that fraction as determined by NO3- : PO43- can be quantitatively predicted from isotopic composition sub-euphotic Our linear model thus provides critically important framework for interpreting δ15N signatures incorporated into both modern marine biomass organic material historical paleoceanographic archives along margin.