Abstract
Observations from a year-long deep current meter mooring at 8°N, 52°W are used to describe the structure and variability of the Deep Western Boundary Current (DWBC) in the tropical Atlantic. The DWBC has a deep core near 4300 m depth, is extremely swift and narrow (35 cm s-1 core speed, 60 km width), and shows a total transport of 22 Sv between 2500 m and the bottom. Approximately 3 Sv of the DWBC transport are carried in near-bottom layers below θ=1.8°C, which appears to be recirculating in the western tropical Atlantic north of about 4°N. Variations in the DWBC are dominated by large-amplitude vertical displacements of the deep temperature field at 60-70 day periodicities that cause significant changes in the deep stratification and vertical transport structure of the DWBC. These fluctuaions appear to be related to periodic surges of cold bottom waters up onto the base of the continental rise that become entrained in the DWBC. While the forcing mechanism for these deep fluctuations remains unexplained, the picture emerging from these data is that of a highly active abyssal layer in the tropical Atlantic.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 293-310 |
| Number of pages | 18 |
| Journal | Deep-Sea Research Part I |
| Volume | 40 |
| Issue number | 2 |
| DOIs | |
| State | Published - 1993 |
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ASJC Scopus subject areas
- Aquatic Science
- Geology
- Oceanography
- Earth and Planetary Sciences(all)
- Environmental Science(all)
Cite this
Deep western boundary current variability off northeastern Brazil. / Johns, William E; Fratantoni, David M.; Zantopp, Rainer J.
In: Deep-Sea Research Part I, Vol. 40, No. 2, 1993, p. 293-310.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Deep western boundary current variability off northeastern Brazil
AU - Johns, William E
AU - Fratantoni, David M.
AU - Zantopp, Rainer J.
PY - 1993
Y1 - 1993
N2 - Observations from a year-long deep current meter mooring at 8°N, 52°W are used to describe the structure and variability of the Deep Western Boundary Current (DWBC) in the tropical Atlantic. The DWBC has a deep core near 4300 m depth, is extremely swift and narrow (35 cm s-1 core speed, 60 km width), and shows a total transport of 22 Sv between 2500 m and the bottom. Approximately 3 Sv of the DWBC transport are carried in near-bottom layers below θ=1.8°C, which appears to be recirculating in the western tropical Atlantic north of about 4°N. Variations in the DWBC are dominated by large-amplitude vertical displacements of the deep temperature field at 60-70 day periodicities that cause significant changes in the deep stratification and vertical transport structure of the DWBC. These fluctuaions appear to be related to periodic surges of cold bottom waters up onto the base of the continental rise that become entrained in the DWBC. While the forcing mechanism for these deep fluctuations remains unexplained, the picture emerging from these data is that of a highly active abyssal layer in the tropical Atlantic.
AB - Observations from a year-long deep current meter mooring at 8°N, 52°W are used to describe the structure and variability of the Deep Western Boundary Current (DWBC) in the tropical Atlantic. The DWBC has a deep core near 4300 m depth, is extremely swift and narrow (35 cm s-1 core speed, 60 km width), and shows a total transport of 22 Sv between 2500 m and the bottom. Approximately 3 Sv of the DWBC transport are carried in near-bottom layers below θ=1.8°C, which appears to be recirculating in the western tropical Atlantic north of about 4°N. Variations in the DWBC are dominated by large-amplitude vertical displacements of the deep temperature field at 60-70 day periodicities that cause significant changes in the deep stratification and vertical transport structure of the DWBC. These fluctuaions appear to be related to periodic surges of cold bottom waters up onto the base of the continental rise that become entrained in the DWBC. While the forcing mechanism for these deep fluctuations remains unexplained, the picture emerging from these data is that of a highly active abyssal layer in the tropical Atlantic.
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UR - http://www.scopus.com/inward/citedby.url?scp=0027387715&partnerID=8YFLogxK
U2 - 10.1016/0967-0637(93)90005-N
DO - 10.1016/0967-0637(93)90005-N
M3 - Article
AN - SCOPUS:0027387715
VL - 40
SP - 293
EP - 310
JO - Deep-Sea Research Part I: Oceanographic Research Papers
JF - Deep-Sea Research Part I: Oceanographic Research Papers
SN - 0967-0637
IS - 2
ER -