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

. The southwestern Pacific Ocean sits at a bifurcation where southern subtropicalwaters are redistributed equatorward and poleward by different oceancurrents. The processes governing the interannual variability of thesecurrents are not completely understood. This issue is investigated using aprobabilistic modeling strategy that allows disentangling theatmospherically forced deterministic ocean variability and the chaoticintrinsic ocean variability. A large ensemble of 50 simulations performed withthe same ocean general circulation model (OGCM) driven by the same realisticatmospheric forcing and only differing by a small initial perturbation isanalyzed over 1980–2015. Our results show that, in the southwestern Pacific, theinterannual variability of the transports is strongly dominated by chaoticocean variability south of 20∘ S. In the tropics, while theinterannual variability of transports and eddy kinetic energy modulation arelargely deterministic and explained by the El Niño–Southern Oscillation (ENSO),ocean nonlinear processes still explain 10 % to 20 % oftheir interannual variance at large scale. Regions of strong chaotic variancegenerally coincide with regions of high mesoscale activity, suggesting that aspontaneous inverse cascade is at work from the mesoscale toward lower frequenciesand larger scales. The spatiotemporal features of the low-frequency oceanicchaotic variability are complex but spatially coherent within certainregions. In the Subtropical Countercurrent area, they appear asinterannually varying, zonally elongated alternating current structures, whilein the EAC (East Australian Current) region, they are eddy-shaped. Given thisstrong imprint of large-scale chaotic oceanic fluctuations, our resultsquestion the attribution of interannual variability to the atmospheric forcingin the region from pointwise observations and one-member simulations.

Imprint of chaotic ocean variability on transports in the southwestern Pacific at interannual timescales