scholarly journals Retention and Leakage of Water by Mesoscale Eddies in the East Australian Current System

2019 ◽  
Vol 124 (4) ◽  
pp. 2485-2500 ◽  
Author(s):  
Paulina Cetina‐Heredia ◽  
Moninya Roughan ◽  
Erik Sebille ◽  
Shane Keating ◽  
Gary B. Brassington
Keyword(s):  
Current System ◽  
Mesoscale Eddies ◽  
East Australian Current

Patterns in larval reef fish distributions and assemblages, with implications for local retention in mesoscale eddies

2018 ◽  
Vol 75 (2) ◽  
pp. 180-192 ◽  
Author(s):  
K. Shulzitski ◽  
S. Sponaugle ◽  
M. Hauff ◽  
K.D. Walter ◽  
E.K. D’Alessandro ◽  
...  
Keyword(s):  
Larval Fish ◽  
Current System ◽  
Age Distribution ◽  
Mesoscale Eddies ◽  
Larval Transport ◽  
Boundary Current ◽  
Straits Of Florida ◽  
Structuring Element ◽  
Larval Distribution ◽  
Species Specific

Benthic marine populations are often replenished by a combination of larvae from local and distant sources. To promote retention of locally spawned larvae in strong, unidirectional boundary current systems, benthic marine organisms must utilize biophysical mechanisms to minimize advective loss. We examined patterns in larval fish abundance, age distribution, and assemblage in relation to environmental variables in the Straits of Florida to better understand the factors underlying larval transport and retention in a boundary current system. Depth was the primary structuring element; larval assemblages were more distinct across vertical distances of tens of metres than they were over horizontal distances of tens to hundreds of kilometres. However, depth distributions were species-specific, and larval assemblages inside and outside of mesoscale eddies were distinct. Age distributions were consistent with the hypothesis that mesoscale eddies provide opportunities for retention. Our data indicate that the effect of eddies on larval retention is likely taxon-specific and temporally variable, as synchronization of reproductive output, larval distribution, and timing of eddy passage are prerequisite to entrainment and subsequent retention of locally spawned larvae.

The Dynamics of the East Australian Current System: The Tasman Front, the East Auckland Current, and the East Cape Current

2001 ◽  
Vol 31 (10) ◽  
pp. 2917-2943 ◽  
Author(s):  
Charles E. Tilburg ◽  
Harley E. Hurlburt ◽  
James J. O'Brien ◽  
Jay F. Shriver
Keyword(s):  
Current System ◽  
East Australian Current

scholarly journals A high-resolution biogeochemical model (ROMS 3.4 + bio_Fennel) of the East Australian Current system

2019 ◽  
Vol 12 (1) ◽  
pp. 441-456 ◽  
Author(s):  
Carlos Rocha ◽  
Christopher A. Edwards ◽  
Moninya Roughan ◽  
Paulina Cetina-Heredia ◽  
Colette Kerry
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Fishery Management ◽  
Numerical Models ◽  
Current System ◽  
Ecosystem Dynamics ◽  
Biogeochemical Model ◽  
East Australian Current ◽  
Surface Patterns ◽  
Insight Into

Abstract. Understanding phytoplankton dynamics is critical across a range of topics, spanning from fishery management to climate change mitigation. It is particularly interesting in the East Australian Current (EAC) system, as the region's eddy field strongly conditions nutrient availability and therefore phytoplankton growth. Numerical models provide unparalleled insight into these biogeochemical dynamics. Yet, to date, modelling efforts off southeastern Australia have either targeted case studies (small spatial and temporal scales) or encompassed the whole EAC system but focused on climate change effects at the mesoscale (with a spatial resolution of 1/10∘). Here we couple a model of the pelagic nitrogen cycle (bio_Fennel) to a 10-year high-resolution (2.5–5 km horizontal) three-dimensional ocean model (ROMS) to resolve both regional and finer-scale biogeochemical processes occurring in the EAC system. We use several statistical metrics to compare the simulated surface chlorophyll to an ocean colour dataset (Copernicus-GlobColour) for the 2003–2011 period and show that the model can reproduce the observed phytoplankton surface patterns with a domain-wide RMSE of approximately 0.2 mg Chl a m−3 and a correlation coefficient of 0.76. This coupled configuration will provide a much-needed framework to examine phytoplankton variability in the EAC system providing insight into important ecosystem dynamics such as regional nutrient supply mechanisms and biogeochemical cycling occurring in EAC eddies.

scholarly journals The Submesoscale Kinetic Energy Cascade: Mesoscale Absorption of Submesoscale Mixed Layer Eddies and Frontal Downscale Fluxes

2020 ◽  
Vol 50 (9) ◽  
pp. 2573-2589 ◽  
Author(s):  
René Schubert ◽  
Jonathan Gula ◽  
Richard J. Greatbatch ◽  
Burkard Baschek ◽  
Arne Biastoch
Keyword(s):  
Kinetic Energy ◽  
Mixed Layer ◽  
Current System ◽  
Mesoscale Eddies ◽  
Coarse Graining ◽  
Early Summer ◽  
Surface Fluxes ◽  
Energy Cascade ◽  
Near Surface ◽  
Agulhas Current

AbstractMesoscale eddies can be strengthened by the absorption of submesoscale eddies resulting from mixed layer baroclinic instabilities. This is shown for mesoscale eddies in the Agulhas Current system by investigating the kinetic energy cascade with a spectral and a coarse-graining approach in two model simulations of the Agulhas region. One simulation resolves mixed layer baroclinic instabilities and one does not. When mixed layer baroclinic instabilities are included, the largest submesoscale near-surface fluxes occur in wintertime in regions of strong mesoscale activity for upscale as well as downscale directions. The forward cascade at the smallest resolved scales occurs mainly in frontogenetic regions in the upper 30 m of the water column. In the Agulhas ring path, the forward cascade changes to an inverse cascade at a typical scale of mixed layer eddies (15 km). At the same scale, the largest sources of the upscale flux occur. After the winter, the maximum of the upscale flux shifts to larger scales. Depending on the region, the kinetic energy reaches the mesoscales in spring or early summer aligned with the maximum of mesoscale kinetic energy. This indicates the importance of submesoscale flows for the mesoscale seasonal cycle. A case study shows that the underlying process is the mesoscale absorption of mixed layer eddies. When mixed layer baroclinic instabilities are not included in the simulation, the open-ocean upscale cascade in the Agulhas ring path is almost absent. This contributes to a 20% reduction of surface kinetic energy at mesoscales larger than 100 km when submesoscale dynamics are not resolved by the model.

scholarly journals A tale of two eddies: The biophysical characteristics of two contrasting cyclonic eddies in the East Australian Current System

2017 ◽  
Vol 122 (3) ◽  
pp. 2494-2518 ◽  
Author(s):  
M. Roughan ◽  
S. R. Keating ◽  
A. Schaeffer ◽  
P. Cetina Heredia ◽  
C. Rocha ◽  
...  
Keyword(s):  
Current System ◽  
East Australian Current

scholarly journals On quartet interactions in the California Current system

2014 ◽  
Vol 21 (4) ◽  
pp. 887-900
Author(s):  
L. M. Ivanov ◽  
C. A. Collins ◽  
T. M. Margolina
Keyword(s):  
Rossby Waves ◽  
Modulational Instability ◽  
Current System ◽  
California Current ◽  
Mesoscale Eddies ◽  
California Current System ◽  
Spectral Centroid ◽  
Zonal Jets ◽  
Near Resonance ◽  
Non Local

Abstract. Sea surface height (SSH) altimetry observations for 1992 to 2009 off California are used to show that observed quasi-zonal jets were likely driven by near-resonance interactions between different scales of the flow. Quartet (modulational) instability dominated and caused non-local transfer of energy from waves and eddies to biannual oscillations and quasi-zonal jets. Two types of quartets were identified: those composed of scales corresponding to (a) quasi-zonal jets, annual and semiannual Rossby waves and mesoscale eddies, and (b) biannual oscillations, semiannual Rossby waves and mesoscale eddies. The spectral centroid regularly shifted into the domain of low-order modes. However, the spectrum of SSHs does not demonstrate a power behavior. This says that the classical inverse cascade is absent. For a case with bottom friction, quartet instability required the existence of a certain level of dissipativity in the flow.

Sign in / Sign up

Export Citation Format

Share Document