Mrs Barbara Johnston
B Science (Hons), DipEd
Contact details for Mrs Barbara Johnston
- Thesis
- Decadal-scale variability in the meridional circulation of iron-rich Upper Circumpolar Deep Water and its impact on primary production in the Southern Ocean.
- Description
- The upwelling of iron-rich Upper Circumpolar Deep Water (UCDW) is thought to be critical for primary production in the Southern Ocean, since iron has been shown to be a limiting factor in what is otherwise a high nutrient region. The position and strength of UCDW upwelling is related to large-scale meridional hydrodynamics and this then affects the regional ecosystem response. Decadal scale changes in the meridional circulation can be linked to changes in the westerly winds, which drive the Antarctic Circumpolar Current (where UCDW upwells), and the ‘efficiency of the biological pump’ in sequestering carbon dioxide in the Southern Ocean. This project will compare the physical variability in upwelling with the variability in the biological response, using a model reanalysis of ocean climate, satellite data on ocean colour and field data.
- Supervisor
- Professor Albert Gabric
- Marine biogeochemistry
- Oceanography
- Peter D. Craig, John R. Hunter and Barbara M Johnston (1993). The implications of linearly varying eddy viscosity for wind driven current profiles. Contintental Shelf Research, 13(1): 1-24.