Insights Into the Biogeochemical Cycling of Iron, Nitrate, and Phosphate Across a 5,300 km South Pacific Zonal Section (153°E–150°W)

• Published in: Global biogeochemical cycles 2018-02, Vol.32 (2), p.187-207
• Main Authors: Ellwood, Michael J., Bowie, Andrew R., Baker, Alex, Gault‐Ringold, Melanie, Hassler, Christel, Law, Cliff S., Maher, William A., Marriner, Andrew, Nodder, Scott, Sander, Sylvia, Stevens, Craig, Townsend, Ashley, Merwe, Pier, Woodward, E. Malcolm S., Wuttig, Kathrin, Boyd, Philip W.
• Format: Article
• Language: English
• Subjects: Atmospheric pollution deposition; Biogeochemical cycles; Biogeochemistry; Biogeography; Chlorophyll; Chlorophylls; Deep water; Essential nutrients; Growth; Iron; Mineral nutrients; nitrate; Nitrates; Nitrogen; Nitrogen fixation; Nitrogen removal; Nutrients; Oceans; Phosphate; Phosphates; Phytoplankton; Plankton; Primary production; Removal; Stoichiometry; Surface water; SW Pacific Ocean; Temperature (air-sea); Upper ocean; Vertical diffusion
• ISSN: 0886-6236; 1944-9224
• DOI: 10.1002/2017GB005736

Iron, phosphate, and nitrate are essential nutrients for phytoplankton growth, and hence, their supply into the surface ocean controls oceanic primary production. Here we present a GEOTRACES zonal section (GP13; 30–33°S, 153°E–150°W) extending eastward from Australia to the oligotrophic South Pacific Ocean gyre outlining the concentrations of these key nutrients. Surface dissolved iron concentrations are elevated at >0.4 nmol L−1 near continental Australia (west of 165°E) and decreased eastward to ≤0.2 nmol L−1 (170°W–150°W). The supply of dissolved iron into the upper ocean (