Hobart

Seminar Abstract

Friday 28 August 2009, 11.30am (Tas time)
CSIRO Auditorium, Hobart

Jan David Zika
PhD student
University of New South Wales/CCRC/CSIRO, Wealth from Oceans
Hobart

Estimating Ocean Circulation and Mixing: Why a scalpel is better than a sledge hammer

Ocean mixing, controls the Global Overturning Circulation. The lack of knowledge of ocean mixing, its magnitude and spatial variation, leads to large uncertainties in our estimates of the volume, heat, freshwater, nutrient and tracer transports and, the role of the ocean in climate variability and feedbacks.

I will give an introduction to ocean mixing and describe the interaction between mixing and ocean circulation. I will discuss methods presently used for estimating ocean circulation from hydrographic data (the "sledge hammer") and discuss their inability to elucidate mixing processes. I will then introduce a new method called the tracer-contour inverse method (the "scalpel"). The tracer-contour inverse method is able to infer the general circulation and mixing from mean hydrographic data alone. That is, observations of temperature salinity and pressure as measured by hydrographic surveys and more recently ARGO floats.

The tracer-contour inverse method is less sensitive to error than conventional techniques. It is validated against both the output of a numerical model and against in-situ observations from the North East Atlantic.

Although there will be some equations in this presentation it will be targeted at a general marine science audience.

Seminar recording

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

For further information, or to schedule a seminar, contact:
To schedule a seminar, contact:
Clothilde Langlais, (Oceanographic seminars) CSIRO Marine and Atmospheric Research (03) 6232 5399
Natalie Kelly, (Biology/Modelling seminars) CSIRO Marine and Atmospheric Research 0438 452 483
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 1/09/09