Mesoscale physical and bio-optical structure of the Antarctic Polar Front near 170°W during austral spring
As part of the U.S. Joint Global Ocean Flux Study Southern Ocean program, high-resolution surveys of the Antarctic Polar Front near 170øW were conducted during October-November 1997 with a towed undulating system equipped with conductivity-temperature-depth and bio-optical sensors. Transects along 1...
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ftoregonstate:ir.library.oregonstate.edu:6682x551w 2024-04-14T08:04:37+00:00 Mesoscale physical and bio-optical structure of the Antarctic Polar Front near 170°W during austral spring Barth, John A. Cowles, Timothy J. Pierce, Stephen D. https://ir.library.oregonstate.edu/concern/articles/6682x551w English [eng] eng unknown American Geophysical Union https://ir.library.oregonstate.edu/concern/articles/6682x551w Copyright Not Evaluated Article ftoregonstate 2024-03-21T15:41:55Z As part of the U.S. Joint Global Ocean Flux Study Southern Ocean program, high-resolution surveys of the Antarctic Polar Front near 170øW were conducted during October-November 1997 with a towed undulating system equipped with conductivity-temperature-depth and bio-optical sensors. Transects along 170°W and two successive mapping surveys revealed zonal bands with sharp meridional gradients in east-west velocity. The Polar Front (PF) was characterized by a sea surface temperature drop from 1.6° to -1.6°C between 60.35° and 61.10°S, with eastward velocities of 0.4-0.5m s¯1 in the core of the PF jet. Deep mixed layers (> 200 m) were found within and north of the PF, but mixed layers shoaled to 100-125m south of the PF to the edge of loose ice at 62.3°S. Highest mixed layer chlorophyll concentration (0.35 mg m¯3) in late October along 170°W were to the south of the PF and associated with cold, fresh water. A large meander of the PF was observed with an alongfront wavelength of 175 km, a cross-front peak-to-peak amplitude of 100 km, and an eastward phase propagation of 0.05-0.08m s¯1, all of which are consistent with its formation via hydrodynamic instability of the PF jet. Highest-phytoplankton biomass was located just poleward of the center of the PF jet. A high-chlorophyll (up to 1.1 mg m¯3) 50 by 50 km region was found downstream of the cyclonic bend associated with the meander. A survey 7.5 days later revealed growth of this high biomass regions to that chlorophyll as in excess of 0.8mg m¯3 over an 80 km cross front by (at least) 80 km along front region. High biomass was observed to grow in place with respect to the meander rather than being displaced far downstream as would be expected from advection. This pattern is consistent with meander-driven upwelling of nutrients and/or trace metals, which in turn stimulates phytoplankton growth. Detailed cross sections of the PF reveal narrow 10-20 km wide bands or filaments of phytoplankton biomass that have temperature/salinity properties distinct from surrounding ... Article in Journal/Newspaper Antarc* Antarctic Southern Ocean ScholarsArchive@OSU (Oregon State University) Antarctic Southern Ocean The Antarctic Austral |
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Open Polar |
collection |
ScholarsArchive@OSU (Oregon State University) |
op_collection_id |
ftoregonstate |
language |
English unknown |
description |
As part of the U.S. Joint Global Ocean Flux Study Southern Ocean program, high-resolution surveys of the Antarctic Polar Front near 170øW were conducted during October-November 1997 with a towed undulating system equipped with conductivity-temperature-depth and bio-optical sensors. Transects along 170°W and two successive mapping surveys revealed zonal bands with sharp meridional gradients in east-west velocity. The Polar Front (PF) was characterized by a sea surface temperature drop from 1.6° to -1.6°C between 60.35° and 61.10°S, with eastward velocities of 0.4-0.5m s¯1 in the core of the PF jet. Deep mixed layers (> 200 m) were found within and north of the PF, but mixed layers shoaled to 100-125m south of the PF to the edge of loose ice at 62.3°S. Highest mixed layer chlorophyll concentration (0.35 mg m¯3) in late October along 170°W were to the south of the PF and associated with cold, fresh water. A large meander of the PF was observed with an alongfront wavelength of 175 km, a cross-front peak-to-peak amplitude of 100 km, and an eastward phase propagation of 0.05-0.08m s¯1, all of which are consistent with its formation via hydrodynamic instability of the PF jet. Highest-phytoplankton biomass was located just poleward of the center of the PF jet. A high-chlorophyll (up to 1.1 mg m¯3) 50 by 50 km region was found downstream of the cyclonic bend associated with the meander. A survey 7.5 days later revealed growth of this high biomass regions to that chlorophyll as in excess of 0.8mg m¯3 over an 80 km cross front by (at least) 80 km along front region. High biomass was observed to grow in place with respect to the meander rather than being displaced far downstream as would be expected from advection. This pattern is consistent with meander-driven upwelling of nutrients and/or trace metals, which in turn stimulates phytoplankton growth. Detailed cross sections of the PF reveal narrow 10-20 km wide bands or filaments of phytoplankton biomass that have temperature/salinity properties distinct from surrounding ... |
format |
Article in Journal/Newspaper |
author |
Barth, John A. Cowles, Timothy J. Pierce, Stephen D. |
spellingShingle |
Barth, John A. Cowles, Timothy J. Pierce, Stephen D. Mesoscale physical and bio-optical structure of the Antarctic Polar Front near 170°W during austral spring |
author_facet |
Barth, John A. Cowles, Timothy J. Pierce, Stephen D. |
author_sort |
Barth, John A. |
title |
Mesoscale physical and bio-optical structure of the Antarctic Polar Front near 170°W during austral spring |
title_short |
Mesoscale physical and bio-optical structure of the Antarctic Polar Front near 170°W during austral spring |
title_full |
Mesoscale physical and bio-optical structure of the Antarctic Polar Front near 170°W during austral spring |
title_fullStr |
Mesoscale physical and bio-optical structure of the Antarctic Polar Front near 170°W during austral spring |
title_full_unstemmed |
Mesoscale physical and bio-optical structure of the Antarctic Polar Front near 170°W during austral spring |
title_sort |
mesoscale physical and bio-optical structure of the antarctic polar front near 170°w during austral spring |
publisher |
American Geophysical Union |
url |
https://ir.library.oregonstate.edu/concern/articles/6682x551w |
geographic |
Antarctic Southern Ocean The Antarctic Austral |
geographic_facet |
Antarctic Southern Ocean The Antarctic Austral |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
https://ir.library.oregonstate.edu/concern/articles/6682x551w |
op_rights |
Copyright Not Evaluated |
_version_ |
1796301263804039168 |