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

The flow of Pacific water to the North Atlantic exerts a globally significant control on nutrient balances between the two ocean basins and strongly influences biological productivity in the northwest Atlantic. Nutrient ratios of nitrate (NOinline-formula $M1inlinescrollmathml{}_{normal 3}^{-}$ 9pt16ptsvg-formulamathimg5c4cefaf8b78d41c1ce2f2ef151f712f bg-18-4491-2021-ie00001.svg9pt16ptbg-18-4491-2021-ie00001.png ) versus phosphate (POinline-formula $M2inlinescrollmathml{}_{normal 4}^{normal 3-}$ 13pt17ptsvg-formulamathimg2a55aaddcd6f6e19827895ad406d0cde bg-18-4491-2021-ie00002.svg13pt17ptbg-18-4491-2021-ie00002.png ) have previously been used to complement salinity characteristics in tracing the distribution of Pacific water in the North Atlantic. We expand on this premise and demonstrate that the fraction of Pacific water as determined by NOinline-formula $M3inlinescrollmathml{}_{normal 3}^{-}$ 9pt16ptsvg-formulamathimg0aaab3ee324d7a9ba8e4b96f67d8036e bg-18-4491-2021-ie00003.svg9pt16ptbg-18-4491-2021-ie00003.png  : POinline-formula $M4inlinescrollmathml{}_{normal 4}^{normal 3-}$ 13pt17ptsvg-formulamathimg7f061630cc7a553581bebfa758ce3c6c bg-18-4491-2021-ie00004.svg13pt17ptbg-18-4491-2021-ie00004.png ratios can be quantitatively predicted from the isotopic composition of sub-euphotic nitrate in the northwest Atlantic. Our linear model thus provides a critically important framework for interpreting inline-formulaδ15N signatures incorporated into both modern marine biomass and organic material in historical and paleoceanographic archives along the northwest Atlantic margin.

### Zitieren

Zitierform:

Sherwood, Owen A. / Davin, Samuel H. / Lehmann, Nadine / et al: Stable isotope ratios in seawater nitrate reflect the influence of Pacific water along the northwest Atlantic margin. 2021. Copernicus Publications.

### Zugriffsstatistik

Gesamt:
Volltextzugriffe: