If you are experiencing problems downloading PDF or HTML fulltext, our helpdesk recommend clearing your browser cache and trying again. If you need help in clearing your cache, please click here . Still need help? Email help@ingentaconnect.com

Free Content Circulation and water masses of the southwest Pacific: WOCE Section P11, Papua New Guinea to Tasmania

Download Article:

Abstract:

The circulation near the western boundary of the South Pacific is described on the basis of water properties and geostrophic velocities measured on a meridional section along 155E through the East Australian and Coral Basins. The section was occupied in winter 1993 as part of the World Ocean Circulation Experiment (WOCE, Section P11S). The primary objective of P11 was to quantify the zonal flows entering and leaving the western boundary of the basin.

The primary inflow to the Tasman and Coral seas is supplied by the South Equatorial Current (SEC), which crosses the P11 section as a wide band of westward flow between 14 and 18S with a total geostrophic transport of 55 Sv (1 Sv = 106 m3/s) relative to the bottom. The SEC bifurcates at the Australian coast near 18S: 29 Sv turns south to feed the East Australian Current (EAC), and 26 Sv recirculates in the Gulf of Papua New Guinea as a low-latitude western boundary current (the Great Barrier Reef and New Guinea Coastal Undercurrents, GBRUC/NGCUC). The NGCUC closes the tropical gyre, and carries South Pacific water around the Louisiade Archipelago and through the Solomon Sea to the equator.

The core of the EAC lies over the continental slope between 18S and 30S. A system of deep-reaching, recirculating eddies or gyres is located offshore of the EAC. At 30S the EAC separates from the coast, and the steeply sloping isopycnals associated with the current persist from the surface to the bottom. The total geostrophic transport of the EAC after separation is 57 Sv relative to the bottom. After separation from the coast, more than half of the EAC (33 Sv) recirculates north and then west, crossing P11 again at 28S. The remainder (24 Sv) continues east as a meandering jet across the Tasman Sea (the Tasman Front).

The circulation in the southern part of the Tasman Sea is dominated by transient eddies and standing gyres. An anticyclonic circulation facilitates the exchange of water between the Tasman Sea and the Southern Ocean. About 10 Sv of subantarctic water spreads north to 36-38S, then recirculates back to the west to merge with a weak southward flow of modified subtopical water near the Tasmanian coast. The circulation in the deeper layers consists of a weak northward deep western boundary current, a cyclonic recirculation filling the Tasman Basin, and a net export of about 3 Sv of deep water to the Coral Sea.

The transport of mode and intermediate water in the low-latitude western boundary current crossing P11 is similar to the transport in these density classes further "upstream" in the subtropical gyre at 32S. This suggests that the mode and intermediate waters entering the Pacific from the south to compensate the export through the Indonesian passages are carried north to the tropical western Pacific primarily along isopycnals.

Document Type: Research Article

DOI: http://dx.doi.org/10.1357/002224000321511151

Publication date: March 1, 2000

More about this publication?
  • The Journal of Marine Research publishes peer-reviewed research articles covering a broad array of topics in physical, biological and chemical oceanography. Articles that deal with processes, as well as those that report significant observations, are welcome. In the area of biology, studies involving coupling between ecological and physical processes are preferred over those that report systematics. Authors benefit from thorough reviews of their manuscripts, where an attempt is made to maximize clarity. The time between submission and publication is kept to a minimum; there is no page charge.
  • Editorial Board
  • Information for Authors
  • Subscribe to this Title
  • ingentaconnect is not responsible for the content or availability of external websites
Related content

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more