Ocean Sciences Editors' Highlights

Unraveling Hemispheric Ocean Nitrate Supply Pathways

Subsurface measurements of nitrogen and oxygen isotope ratios in nitrate reveal a predominantly southern hemisphere supply of nitrate to the equatorial Pacific.

Source: Journal of Geophysical Research: Oceans


The equatorial Pacific exerts an important influence on lower latitude biogeochemistry and supports nearly ten percent of global primary production. It has long been suggested that nutrients in the equatorial Pacific originate from the Southern Ocean but few studies have attempted to determine the source and quantify the contribution. Using a combination of geochemical tracers that aren’t often measured together, especially not in this combination, Lehmann et al. [2018] support and justify the theory of a predominantly Southern Ocean source of nitrate. In addition to unraveling the sources, transformation, and communication of subsurface nutrients, these results are of value in predicting local and regional biogeochemical variability in this region.

Citation: Lehmann, N., Granger, J., Kienast, M., Brown, K. S., Rafter, P. A., Martínez-Méndez, G., et al. [2018]. Isotopic evidence for the evolution of subsurface nitrate in the Western Equatorial Pacific. Journal of Geophysical Research: Oceans, 123. https://doi.org/10.1002/2017JC013527

—S. Bradley Moran, Editor, JGR: Oceans

© 2018. The authors. CC BY-NC-ND 3.0