US Student Participants
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Gabriela Mayorga-Adame US student participant in 2007 now graduate student College of Oceanic and Atmospheric Sciences Oregon State University Tel.: +1 (541) 737-9831 Email: |
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General | Progress Reports | Final Report | Personal Blog
Final Report
Mayorga-Adame, C.G.: 2007, Ocean circulation of the Zanzibar Channel: A modeling approach. (pdf)
Summary. The dynamics of the Zanzibar Channel is virtually unkown. Gabriela Mayorga-Adame therefore set up a Regional Ocean Modeling System (ROMS) model of the Zanzibar Channel and began to study semi-idealized cases. As an initial condition she assumed constant temperature and salinity throughout the channel and the northern and southern channel entrances were considered open boundaries. She considered two cases with constant wind forcing, using a typical speed and direction during the peak of each of the two monsoon phases as measured by the meteorological station at Zanzibar airport. The model output shows that in both cases the surface flow has largely the same direction as the wind. Its speed is small near Zanzibar Town in the center of the eastern part of the channel where the flow is also being deflected westward. The bottom flow follows mainly the bottom topography. A difference between the two cases is that upwelling occurs at the western shore of Zanzibar only during the Southwest Monsoon (southeasterly winds). A third case study was on tidal dynamics. The global tide model TPX07 reveals that the M2 tidal component generates the largest velocities in the channel and was therefore selected as the forcing on both channel entrances. The resulting dynamics produced by the model features water masses entering the channel at both entrances and piling up approximately in front of Zanzibar Town during flood and exiting at both entrances during ebb. For this case, fortunately, direct observations had been made in the past (Shaghude et al., 2002), confirming that the model qualitatively reproduces this unique feature and the flow speeds are comparable (see also Harvey 1977; Mohammed et al., 1993).