ANALYSIS
Interocean exchange
The three boxes that make up the survey area allow for absolute flux
calculations using conservation of mass, heat (away from the surface) and
salt. For example, the following equation conserves mass in a box,
On the left are the unknowns; the reference velocity flux, evaporation
minus precipitation, and noise resulting from lack of synopticity and
high frequency fluctuations in the measurements. On the right hand
side are the measured geostrophic and ageostrophic (primarily Ekman)
fluxes. The latter will be computed from underway ADCP data using the
method of Chereskin and Roemmich, (1991).
The reference velocities will be initialised using LADCP data, after Beal and Bryden (1999). An inverse model will be set up for each box (Wunsch, 1996), to solve for the unknowns.
Results from applying the inverse model will include an estimate of water mass entrainment, mixing, heat and freshwater budgets and air-sea fluxes of the WBC system. Thus, the quantities of heat and salt available in the Agulhas Current for exchange with the Atlantic Ocean, and in the Undercurrent for ventilation of the Indian Ocean, will be assessed.
- Introduction
- Velocity Structure
- Variability
- Water Masses and Potential Vorticity Structure
- Geostrophy and Transport
- Mooring Array
- Cross-stream sections
- Along-stream sections
- Synopticity and variability
- LADCP experiment design
- Interocean exchange Indian Ocean ventilation
- Velocity and PV fields
- Mean Transport and variability
- Characterisation of mixing