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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

. Microstructure measurements were performed along theOUTPACE longitudinal transect in the tropical Pacific(Moutin and Bonnet, 2015). Small-scale dynamics and turbulence in the first800 m surface layer were characterized based on hydrographic and currentmeasurements at fine vertical scale and turbulence measurements atcentimeter scale using a vertical microstructure profiler. The possibleimpact of turbulence on biogeochemical budgets in the surface layer was alsoaddressed in this region of increasing oligotrophy to the east. Thedissipation rate of turbulent kinetic energy, ϵ, showed aninteresting contrast along the longitudinal transect with strongerturbulence in the west, i.e., the Melanesian Archipelago, compared to theeast, within the South Pacific Subtropical Gyre, with a variation ofϵ by a factor of 3 within [100–500 m]. The layer with enhancedturbulence decreased in vertical extent travelling eastward. This spatialpattern was correlated with the energy level of the internal wave field,higher in the west compared to the east. The difference in wave energy mostlyresulted from enhanced wind power input into inertial motions in the west.Moreover, three long-duration stations were sampled along the cruisetransect, each over three inertial periods. The analysis from the westernlong-duration station gave evidence of an energetic baroclinic near-inertialwave that was responsible for the enhanced ϵ, observed within a50–250 m layer, with a value of 8×10-9 W kg−1, about 8times larger than at the eastern long-duration stations. Averaged nitrateturbulent diffusive fluxes in a 100 m layer below the top of thenitracline were about twice larger west of 170∘ W due to thehigher vertical diffusion coefficient. In the photic layer, thedepth-averaged nitrate turbulent diffusive flux strongly decreasedeastward, with an averaged value of 11 µmolm-2d-1 west of170∘ W compared with the 3 µmolm-2d-1 averagedvalue east of 170∘ W. Contrastingly, phosphate turbulent diffusivefluxes were significantly larger in the photic layer. This input may have animportant role in sustaining the development of N2-fixing organismsthat were shown to be the main primary contributors to the biological pump inthe area. The time–space intermittency of mixing events, intrinsic toturbulence, was underlined, but its consequences for micro-organisms woulddeserve a dedicated study.

Longitudinal contrast in turbulence along a ∼ 19° S section in the Pacific and its consequences for biogeochemical fluxes