Interannual variability of South Equatorial Current bifurcation and western boundary currents along the Madagascar coast

2015 ◽  
Vol 120 (12) ◽  
pp. 8551-8570 ◽  
Author(s):  
Y. Yamagami ◽  
T. Tozuka
Keyword(s):  
Interannual Variability ◽  
Western Boundary ◽  
Western Boundary Currents ◽  
South Equatorial Current ◽  
Boundary Currents ◽  
Equatorial Current

Forced and chaotic variability of interannual variability of regional sea level and its causes scale over 1993-2015

2020 ◽  
Author(s):  
Alice Carret ◽  
William Llovel ◽  
Thierry Penduff ◽  
Jean-Marc Molines ◽  
Benoît Meyssignac
Keyword(s):  
Interannual Variability ◽  
Sea Level ◽  
Satellite Altimetry ◽  
Global Ocean ◽  
Western Boundary ◽  
Western Boundary Currents ◽  
Steric Sea Level ◽  
Boundary Currents ◽  
Ocean Variability ◽  
Regional Sea Level

<p>Since the early 1990s, satellite altimetry has become the main observing system for continuously measuring the sea level variations with a near global coverage. Satellite altimetry has revealed a global mean sea level rise of 3.3 mm/yr since 1993 with large regional sea level variability that differs from the mean estimate. These measurements highlight complex structures especially for the western boundary currents or the Antarctic Circumpolar Current. A recent study shows that the chaotic ocean variability may mask atmospherically-forced regional sea level trends over 38% of the global ocean area from 1993 to 2015. The chaotic variability is large for the western boundary currents and in the Southern Ocean. The present study aims to complement this previous work in focusing on the interannual variability of regional sea level. A global ¼° ocean/sea-ice 50-member ensemble simulation is considered to disentangle the imprints of the atmospheric forcing and the chaotic ocean variability on the interannual variability of regional sea level over 1993-2015. We investigate the forced (i.e., ensemble mean) versus the chaotic variability (i.e., ensemble standard deviation) for the interannual variability of regional sea level and its causes (i.e., steric sea level and manometric sea level contribution). We complement our investigations by partitioning the steric component into thermosteric sea level (i.e., temperature change only) and halosteric sea level (i.e., salinity change only). One of the goals of the study is to highlight the hot spots region of large chaotic variability for regional sea level and its different components.</p>

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 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

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.

Observations of atmosphere-ocean coupling in midlatitude western boundary currents

1996 ◽  
Vol 101 (C3) ◽  
pp. 6295-6312 ◽  
Author(s):  
Kathryn A. Kelly ◽  
Michael J. Caruso ◽  
Sandipa Singh ◽  
Bo Qiu
Keyword(s):  
Western Boundary ◽  
Western Boundary Currents ◽  
Boundary Currents ◽  
Ocean Coupling
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