English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Mesoscale eddies are important, frequent, and persistent features of thecirculation in the eastern South Pacific (ESP) Ocean, transporting physical,chemical and biological properties from the productive shelves to the openocean. Some of these eddies exhibit subsurface hypoxic or suboxic conditionsand may serve as important hotspots for nitrogen loss, but little is knownabout oxygen consumption rates and nitrogen transformation processesassociated with these eddies. In the austral fall of 2011, during the TaraOceans expedition, an intrathermocline, anticyclonic, mesoscale eddy with asuboxic (< 2 µmol kg−1 of O2), subsurface layer(200–400 m) was detected  ∼  900 km off the Chilean shore(30° S, 81° W). The core of the eddy's suboxic layer hada temperature-salinity signature characteristic of Equatorial SubsurfaceWater (ESSW) that at this latitude is normally restricted to an area nearthe coast. Measurements of nitrogen species within the eddy revealedundersaturation (below 44 %) of nitrous oxide (N2O) and nitriteaccumulation (> 0.5 µM), suggesting that activedenitrification occurred in this water mass. Using satellite altimetry, wewere able to track the eddy back to its region of formation on the coast ofcentral Chile (36.1° S, 74.6° W). Field studiesconducted in Chilean shelf waters close to the time of eddy formationprovided estimates of initial O2 and N2O concentrations of theESSW source water in the eddy. By the time of its offshore sighting,concentrations of both O2 and N2O in the subsurface oxygen minimumzone (OMZ) of the eddy were lower than concentrations in surrounding waterand “source water” on the shelf, indicating that these chemical species wereconsumed as the eddy moved offshore. Estimates of apparent oxygenutilization rates at the OMZ of the eddy ranged from 0.29 to 44 nmol L−1 d−1 and the rate of N2O consumption was 3.92 nmol L−1 d−1. These results show that mesoscale eddies affectopen-ocean biogeochemistry in the ESP not only by transporting physical andchemical properties from the coast to the ocean interior but also duringadvection, local biological consumption of oxygen within an eddy furthergenerates conditions favorable to denitrification and loss of fixed nitrogenfrom the system

Biogeochemical characteristics of a long-lived anticyclonic eddy in the eastern South Pacific Ocean