Hobart

Seminar Abstract

Tuesday 5 August 2008, 11.30am (Tas time)
CSIRO Auditorium, Hobart

Niklas Schneider
International Pacific Research Center & Department of Oceanography
University of Hawaii at Manoa Honolulu, Hawaii, USA

The Kuroshio Large Meander in an eddy-resolving ocean model

The Kuroshio is unique among the western boundary currents in that it occupies discreet paths for many years, with transitions occurring on much shorter time scales. Kuroshio path dynamics are investigated using a 50 year, near global, eddy resolving hindcast with the Ocean Model for the Earth Simulator. The model produces vigorous fluctuation of the Kuroshio path with interannual to decadal time scales. Starting from a straight path, a meander develops close to Izu ridge. This meander then slowly retrogrades and strengthens until the system become unstable and resets to a straight path. Analysis of potential vorticity indicates that the path curvature results from all terms with a near-balance of large and opposite fluctuations of shear vorticity and layer thickness due to divergences of the ageostrophic flow. These are traced to the slow eddy-driven build-up of low potential vorticity in the anticyclonic recirculation gyre. Differences of observed and simulated path evolution are attributed to an underestimation of lateral exchange processes in the model.

[back]

Location:
CSIRO = Marine Laboratories Auditorium, Castray Esplanade, Hobart

For further information, or to schedule a seminar, contact:
To schedule a seminar, contact:
Bernadette Sloyan, (Oceanographic seminars) CSIRO Marine and Atmospheric Research (03) 6232 5152
Thomas Kunz, (Biological seminars) CSIRO Marine and Atmospheric Research
(03) 6232 5076
Natalie Dowling, (Fisheries Modelling) CSIRO Marine and Atmospheric Research
(03) 6232 5148
Jillian Enraght-Moony, (seminar administrator) CSIRO Marine and Atmospheric Research (03) 6232 5320
Communications Manager, Antarctic Climate and Ecosystems CRC (03) 6226 2265
Margaret Hazelwood, Institute of Antarctic and Southern Ocean Studies (IASOS) University of Tasmania (03) 6226 2971

Last updated 21/07/09