Bachelor defense by Andy Morris – Niels Bohr Institute - University of Copenhagen

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Bachelor defense by Andy Morris

Title: A Comparison of Equatorial Undercurrent: POP2 Model and Measurement

An in-depth comparison was conducted comparing descriptions of Paci fic equatorial undercurrent of two resolutions of the Parallel Ocean Program model to measurements described in previous papers as well as contemporary data from the TAO/TRITON buoy array. A new model is also proposed to approximate the Galapagos archipelago as a cylinder around which equatorial undercurrent might  flow.

It was found that the Parallel Ocean Program model when run at 1 degree resolution follows measured data measured by Brady and Bryden (1985) as well as from TAO/TRITON much closer than the 0.1 degree model. Neither model was found to behave correctly when thermal properties were tested, with temperatures decreasing by 3.0 degrees C and 3.7 degrees C between longitudes of 150W and 110W, measured previously to be almost isothermal. Also tested are predictions of Ekman eff ects narrowing the width of equatorial undercurrent at depths above 90m. These eff ects were found to be present in the 0.1 degree model but not the 1 degree model.
Attempts to model the Galapagos archipelago cylindrically were unsuccessful, however the 0.1 degree model was directly compared to measured results of Karnauskas et al. (2010) and found to be in reasonable agreement of these measurements.