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

Biogeosciences

article

Sherwood, Owen A.¹  Davin, Samuel H.²  Lehmann, Nadine³  Buchwald, Carolyn³  Edinger, Evan N.⁴  Lehmann, Moritz F.⁵  Kienast, Markus³ 

[1] Department of Earth and Environmental Sciences, Dalhousie University;Geotop Research Centre, Université du Québec à Montréal;Department of Oceanography, Dalhousie University;Department of Geography, Department of Biology, and Department of Earth Sciences, Memorial University of Newfoundland;Department of Environmental Sciences, University of Basel

DOI  :  10.5194/bg-18-4491-2021

学科分类：大气科学

来源: Copernicus Publications

【 摘 要 】

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 (NO 3 - ) versus phosphate (PO 4 3 - ) 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 NO 3 -  : PO 4 3 - 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 δ 15 N signatures incorporated into both modern marine biomass and organic material in historical and paleoceanographic archives along the northwest Atlantic margin.

【 授权许可】

CC BY