scholarly journals From the western boundary currents to the Pacific Equatorial Undercurrent: Modeled pathways and water mass evolutions

2011 ◽  
Vol 116 (C12) ◽  
Author(s):  
Mélanie Grenier ◽  
Sophie Cravatte ◽  
Bruno Blanke ◽  
Christophe Menkes ◽  
Ariane Koch-Larrouy ◽  
...  
Keyword(s):  
Water Mass ◽  
Western Boundary ◽  
Western Boundary Currents ◽  
Equatorial Undercurrent ◽  
Boundary Currents ◽  
The Pacific

Spatial variability of phytoplankton in the Pacific western boundary currents during summer 2014

2017 ◽  
Vol 68 (10) ◽  
pp. 1887
Author(s):  
Yunyan Chen ◽  
Xiaoxia Sun ◽  
Mingliang Zhu ◽  
Shan Zheng ◽  
Yongquan Yuan ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Size Fraction ◽  
Western Boundary ◽  
Flow Cytometry Analysis ◽  
Concentration Data ◽  
Western Boundary Currents ◽  
Chl A ◽  
Boundary Currents ◽  
The North ◽  
The Pacific

The spatial distribution of phytoplankton was investigated during the summer of 2014 in two different regions of the Pacific western boundary current, namely the Warm Pool near the equator and the subtropical Kuroshio south area. Traditional approaches (size-fractionated chlorophyll-a (Chl-a) and microscopic analyses) combined with single-cell analysis (using a flow cytometer) were used to analyse the whole range of phytoplankton. Flow cytometry analysis resolved five clusters, two belonging to the pico-size fraction and three belonging to the nano-size fraction. Microscopy analysis revealed that the genera Coscinodiscus, Rhizosolenia, Chaetoceros and Ceratium were numerically dominant in the region studied. The lowest values of Chl-a, phytoplankton abundance and carbon biomass were found in the Kuroshio south area. Both Chl-a concentration data and flow cytometry analysis revealed that picophytoplankton were the predominant contributors to phytoplankton in the Pacific western boundary currents. Along the three transects during the summer cruise, Synechococcus and nanocyanobacteria-like organisms numerically dominated in surface waters with higher temperature. In contrast, eukaryotes were primarily distributed in subsurface waters with higher nutrients, especially in the eddy upwelling region mainly associated with the North Equatorial Counter Current. The vertical distribution of phytoplankton over the epipelagic layer reinforces the important role of currents in the north-western Pacific during summer.

scholarly journals Pathways into the Pacific Equatorial Undercurrent: A Trajectory Analysis*

2005 ◽  
Vol 35 (11) ◽  
pp. 2134-2151 ◽  
Author(s):  
Paul J. Goodman ◽  
Wilco Hazeleger ◽  
Pedro de Vries ◽  
Mark Cane
Keyword(s):  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Primary Sources ◽  
Western Boundary ◽  
Equatorial Undercurrent ◽  
Boundary Currents ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The Tropics

Abstract A time-dependent trajectory algorithm is used to determine the sources of the Pacific Ocean Equatorial Undercurrent (EUC) in a global climate model with ¼° (eddy permitting) resolution and forced with realistic winds. The primary sources and pathways are identified, and the transformation of properties in temperature/salinity space is explored. An estimate for the quantity of recirculation, a notoriously difficult property to estimate from observational data, is given. Over two-thirds of the water in the Pacific EUC at 140°W originates south of the equator; 70% of the EUC is ventilated outside of the Tropics (poleward of 13°S or 10°N): three-quarters of these extratropical trajectories travel through the western boundary currents between their subduction and incorporation into the EUC, and one-fifth of the extratropical trajectories enter and leave the tropical band at least once before entering the EUC.

scholarly journals Radiating Instability of a Meridional Boundary Current

2008 ◽  
Vol 38 (10) ◽  
pp. 2294-2307 ◽  
Author(s):  
Hristina G. Hristova ◽  
Joseph Pedlosky ◽  
Michael A. Spall
Keyword(s):  
Western Boundary ◽  
Far Field ◽  
Boundary Current ◽  
Important Conclusion ◽  
Western Boundary Currents ◽  
Horizontal Structure ◽  
Boundary Currents ◽  
Zonal Jets ◽  
Eastern Boundary ◽  
Eastern Boundary Current

Abstract A linear stability analysis of a meridional boundary current on the beta plane is presented. The boundary current is idealized as a constant-speed meridional jet adjacent to a semi-infinite motionless far field. The far-field region can be situated either on the eastern or the western side of the jet, representing a western or an eastern boundary current, respectively. It is found that when unstable, the meridional boundary current generates temporally growing propagating waves that transport energy away from the locally unstable region toward the neutral far field. This is the so-called radiating instability and is found in both barotropic and two-layer baroclinic configurations. A second but important conclusion concerns the differences in the stability properties of eastern and western boundary currents. An eastern boundary current supports a greater number of radiating modes over a wider range of meridional wavenumbers. It generates waves with amplitude envelopes that decay slowly with distance from the current. The radiating waves tend to have an asymmetrical horizontal structure—they are much longer in the zonal direction than in the meridional, a consequence of which is that unstable eastern boundary currents, unlike western boundary currents, have the potential to act as a source of zonal jets for the interior of the ocean.

scholarly journals Dynamics of Separating Western Boundary Currents

1999 ◽  
Vol 29 (2) ◽  
pp. 119-144 ◽  
Author(s):  
Ilson C. A. da Silveira ◽  
Glenn R. Flierl ◽  
Wendell S. Brown
Keyword(s):  
Western Boundary ◽  
Western Boundary Currents ◽  
Boundary Currents

scholarly journals A Climatological Interpretation of the Circulation in the Western South Pacific*

2002 ◽  
Vol 32 (9) ◽  
pp. 2492-2508 ◽  
Author(s):  
Tangdong Qu ◽  
Eric J. Lindstrom
Keyword(s):  
Papua New Guinea ◽  
New Guinea ◽  
Western Boundary ◽  
Guinea Coast ◽  
Boundary Currents ◽  
The North ◽  
Intermediate Layers ◽  
Water Property ◽  
The Pacific ◽  
Equatorial Current

Abstract Time-averaged circulation is examined using historical hydrographic data near the Australia and Papua New Guinea coast in the Pacific. By averaging the data along isopycnal surfaces in a 0.5° × 0.5° grid, the authors are able to show many detailed phenomena associated with the narrow western boundary currents, including the vertical structure of the bifurcation latitude of the South Equatorial Current (SEC) and the connection between the Solomon and Coral Seas. The bifurcation latitude of the SEC is found to move southward from about 15°S near the surface to south of 22°S in the intermediate layers. The origin of the Great Barrier Reef Undercurrent (GBRUC) is identified to be at about 22°S. Farther to the north, the GBRUC intensifies underlying the surface East Australian Current, and merges with the North Queensland Current (NQC) at about 15°S. The NQC turns eastward to flow along the Papua New Guinea coast and feeds into the New Guinea Coastal Undercurrent (NGCUC) through the Louisiade Archipelago. Further analysis shows that there is a strong water property connection between the Coral and Solomon Seas, confirming the earlier speculation on the water mass origins of the NGCUC.

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