Article

 

Mesoscale physical and bio-optical structure of the Antarctic Polar Front near 170°W during austral spring Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/articles/6682x551w

copyrighted by American Geophysical Union

Descriptions

Attribute NameValues
Creator
Abstract
  • 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 water and are coherent for at least 120 km alongfront.
Resource Type
Date Available
Date Issued
Citation
  • Barth, J. A., Cowles, T. J., and Pierce, S. D., 2001, Mesoscale physical and bio-optical structure of the Antarctic Polar Front near 170 deg W during spring: J. Geophys. Res., v. 106, p. 13,879-13,902.
Journal Title
Journal Volume
  • 106
Journal Issue/Number
  • C7
Rights Statement
Publisher
Language
Replaces
Additional Information
  • description.provenance : Submitted by Mary Phan (mpscanner@gmail.com) on 2010-04-13T20:51:21Z No. of bitstreams: 1 Barth et al JGR 2001.pdf: 3055935 bytes, checksum: da47c2d31bd6173cfe6d5d10affb1072 (MD5)
  • description.provenance : Made available in DSpace on 2010-04-14T17:05:16Z (GMT). No. of bitstreams: 1 Barth et al JGR 2001.pdf: 3055935 bytes, checksum: da47c2d31bd6173cfe6d5d10affb1072 (MD5) Previous issue date: 2001
  • description.provenance : Submitted by Mary Phan (mpscanner@gmail.com) on 2010-04-12T22:30:01Z No. of bitstreams: 0
  • description.provenance : Approved for entry into archive by Linda Kathman(linda.kathman@oregonstate.edu) on 2010-04-14T17:05:15Z (GMT) No. of bitstreams: 1 Barth et al JGR 2001.pdf: 3055935 bytes, checksum: da47c2d31bd6173cfe6d5d10affb1072 (MD5)
  • description.provenance : Rejected by Linda Kathman(linda.kathman@oregonstate.edu), reason: on 2010-04-12T22:31:26Z (GMT)

Relationships

Parents:

This work has no parents.

Items