HR: 17:15h
AN: OS44A-06    [Abstracts]
TI: Monitoring the East Australian Current - a historical perspective and future plans
AU: * Ridgway, K
EM: ken.ridgway@csiro.au
AF: CSIRO Marine & Atmospheric Research, 1538 Castray Esplanade Battery Point, Hobart, Tas 7001, Australia
AB: We present a review of results from a 15-year time-series of quarterly eddy-resolving XBT surveys of the East Australian Current in the southwestern Pacific. The region contains the South Pacific's subtropical western boundary current system, the East Australian Current (EAC), with its associated intense mesoscale variability. It provides both the western termination of the South Pacific Gyre and a linking element between the Pacific and Indian Ocean gyres. Western Boundary Current systems such as the EAC are important elements of the ocean circulation heat engine, removing excess heat from the tropics and releasing it to the mid-latitude atmosphere. The outflow of the EAC also provides a pathway for mode and intermediate waters to move from the Pacific to the Indian Oceans. This outflow represents a further component of the global thermohaline circulation. The XBT transects are supplemented with observations from research cruises, broad-scale XBT and satellite altimetric height data, and air-sea fluxes from ECMWF and NCEP analyses. Time series of EAC flow from 1993-2004 are generated by merging XBT and altimeter data. Net water mass conversions in the upper ocean reflect the net evaporation and heat loss in the formation of South Pacific Subtropical Mode Water. A multi-year variation in EAC transport is documented and related to decadal SST signals around Tasmania. Connections are made between the Tasman Box observations and both the decadal spin-up of the South Pacific Gyre and the southward penetration of EAC waters to Tasmania. Plans for future observation activity within the SPICE program are outlined.
DE: 4504 Air/sea interactions (0312, 3339)
DE: 4513 Decadal ocean variability (1616, 1635, 3305, 4215)
DE: 4520 Eddies and mesoscale processes
DE: 4532 General circulation (1218, 1222)
DE: 4576 Western boundary currents
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting