Denise Fernandez
Contact
Phone: 04 463 5233 x 8402
Email: address
Office: CO 521
Qualifications
BSc VUW (2010)
MSc Candidate in Physical Oceanography
MSc Thesis
Title
How do the winds control the confluence of subtropical and subpolar waters, east of New Zealand?
Supervisors
Prof Lionel Carter
Melissa Bowen
Project Aim and Description
The ocean off eastern New Zealand is one of only three places in the world where the Antarctic Circumpolar Current (ACC) meets the strong southward flow of a major subtropical gyre. Strong temperature and sea surface height (SSH) gradients or ocean fronts are characteristics of this region along with high vorticity flows known as eddies. Heat, momentum, salts and nutrients, are transferred across frontal boundaries making them highly productive regions in the ocean. Thus, ocean fronts are sensitive places where the impact of modern climatic variability can be assessed. Winds are the major drivers of the upper ocean circulation. Consequently, changes in large-scale wind patterns should influence the location of fronts. However, recent studies have shown that highly energetic eddies, and the ocean bathymetry may be significant controls of the currents and associated fronts.
The aim of this study is to answer the following fundamental question: Are the winds over the South Pacific Ocean the main control of the fronts east of New Zealand?
Satellite-borne sensors provide an opportunity to investigate the link between wind forcing and the ocean dynamics. Altimeter data of the SSH (1992-2010) will be used to study the annual and decadal variability of the extent and intensity of fronts and also will help to delineate the zones and time of greatest eddy activity. The South Pacific wind field will be investigated using satellite scatterometer data. Once the location and intensity of the fronts and eddies have been determined, the influence of the winds can be tested.
The identification of mechanisms controlling the confluence of the northward and southward flows off New Zealand will influence studies of similar confluences throughout the global ocean. Expanding our knowledge and understanding of the connection between the winds and the modern ocean is fundamental to interpret past climatic variability and assess future ocean responses to a warming climate.