Abstract
We present full-depth hydrographic and velocity observations across a solitary meander within the Agulhas Current, and assess the degree to which the meander causes upwelling, cross-frontal mixing, and diapycnal transport. These events can input nutrients onto the continental shelf as well as advect larvae offshore. We find that the meander drives inshore upwelling with vertical velocities of at least 13 m d<sup>-1</sup>. The meander also causes diapycnal transport resulting in 1°C cooler and 0.25 fresher central waters and 1°C warmer, 0.25 saltier intermediate waters below the thermocline. We introduce a new coordinate system that separates these changes into kinematic changes due to meandering and property changes along transport streamlines. This reveals that most of the observed diapycnal transport below the thermocline is due to property changes. We find a small amount of enhanced cross-frontal mixing associated with solitary meanders of the Agulhas Current, but it is statistically insignificant. We believe this is due to the strongly barotropic nature of the meandering Agulhas Current, which maintains a deep steering level that inhibits mixing.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 4503-4515 |
| Number of pages | 13 |
| Journal | Journal of Geophysical Research C: Oceans |
| Volume | 120 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 1 2015 |
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Keywords
- Agulhas Current
- cross-frontal mixing
- hydrographic data
- natal pulse
- solitary meander
- upwelling
ASJC Scopus subject areas
- Geochemistry and Petrology
- Geophysics
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science
- Oceanography
Cite this
Local water mass modifications by a solitary meander in the Agulhas Current. / Leber, Greta M.; Beal, Lisa.
In: Journal of Geophysical Research C: Oceans, Vol. 120, No. 6, 01.06.2015, p. 4503-4515.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Local water mass modifications by a solitary meander in the Agulhas Current
AU - Leber, Greta M.
AU - Beal, Lisa
PY - 2015/6/1
Y1 - 2015/6/1
N2 - We present full-depth hydrographic and velocity observations across a solitary meander within the Agulhas Current, and assess the degree to which the meander causes upwelling, cross-frontal mixing, and diapycnal transport. These events can input nutrients onto the continental shelf as well as advect larvae offshore. We find that the meander drives inshore upwelling with vertical velocities of at least 13 m d-1. The meander also causes diapycnal transport resulting in 1°C cooler and 0.25 fresher central waters and 1°C warmer, 0.25 saltier intermediate waters below the thermocline. We introduce a new coordinate system that separates these changes into kinematic changes due to meandering and property changes along transport streamlines. This reveals that most of the observed diapycnal transport below the thermocline is due to property changes. We find a small amount of enhanced cross-frontal mixing associated with solitary meanders of the Agulhas Current, but it is statistically insignificant. We believe this is due to the strongly barotropic nature of the meandering Agulhas Current, which maintains a deep steering level that inhibits mixing.
AB - We present full-depth hydrographic and velocity observations across a solitary meander within the Agulhas Current, and assess the degree to which the meander causes upwelling, cross-frontal mixing, and diapycnal transport. These events can input nutrients onto the continental shelf as well as advect larvae offshore. We find that the meander drives inshore upwelling with vertical velocities of at least 13 m d-1. The meander also causes diapycnal transport resulting in 1°C cooler and 0.25 fresher central waters and 1°C warmer, 0.25 saltier intermediate waters below the thermocline. We introduce a new coordinate system that separates these changes into kinematic changes due to meandering and property changes along transport streamlines. This reveals that most of the observed diapycnal transport below the thermocline is due to property changes. We find a small amount of enhanced cross-frontal mixing associated with solitary meanders of the Agulhas Current, but it is statistically insignificant. We believe this is due to the strongly barotropic nature of the meandering Agulhas Current, which maintains a deep steering level that inhibits mixing.
KW - Agulhas Current
KW - cross-frontal mixing
KW - hydrographic data
KW - natal pulse
KW - solitary meander
KW - upwelling
UR - http://www.scopus.com/inward/record.url?scp=84937054274&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84937054274&partnerID=8YFLogxK
U2 - 10.1002/2015JC010863
DO - 10.1002/2015JC010863
M3 - Article
AN - SCOPUS:84937054274
VL - 120
SP - 4503
EP - 4515
JO - Journal of Geophysical Research: Oceans
JF - Journal of Geophysical Research: Oceans
SN - 2169-9275
IS - 6
ER -