HR: 1400h
AN: OS53A-12    [Abstracts]
TI: The circulation around Chinchorro Bank
AU: * Coronado, C
EM: coronado@cicese.mx
AF: Department of Physical Oceanography/CICESE, Km 107 Carretera Tijuana-Ensenada, Ensenada, BC 22800, Mexico
AU: Candela, J
EM: jcandela@cicese.mx
AF: Department of Physical Oceanography/CICESE, Km 107 Carretera Tijuana-Ensenada, Ensenada, BC 22800, Mexico
AU: Ochoa, J
EM: jochoa@cicese.mx
AF: Department of Physical Oceanography/CICESE, Km 107 Carretera Tijuana-Ensenada, Ensenada, BC 22800, Mexico
AU: Badan, A
EM: abadan@cicese.mx
AF: Department of Physical Oceanography/CICESE, Km 107 Carretera Tijuana-Ensenada, Ensenada, BC 22800, Mexico
AU: Sheinbaum, J
EM: julios@cicese.mx
AF: Department of Physical Oceanography/CICESE, Km 107 Carretera Tijuana-Ensenada, Ensenada, BC 22800, Mexico
AB: Chinchorro Bank is the only atoll-like reef in the Caribbean Sea, centered at 87° 21' W, 18° 35' N. It has an oval shape and approximately 44 km length and 20 km width. A channel separating its western rim from the Yucatan Peninsula has a width of 30 km and a sill depth of 700 m. The channel has a mean northward current of 30 cm/s implying a mean transport on the order of 7 Sv. Ten months (5/2006-2/2007) of direct measurements at three locations around the Bank, just outside the reef rim at 20 m depth, combined with previous current information from nearby deep-water current moorings, are used to investigate the circulation in the region. The recent dataset includes measurements of the current profile, subsurface pressure, bottom water temperature and surface waves, along with geostrophic current estimates calculated from pressure sensors on both sides of the channel. Although the flow at the three locations have significant westward mean currents, revealing the influence of the large-scale prevailing flow in the Bank's surroundings, only the southern location is highly correlated with the along-channel geostrophic flow. The coastal boundary layer seems to be decoupled from the along-channel main flow at the western (i.e. the lateral boundary of the channel) and the northern reef flanks. Altimetry and drifter observations show southern flow events within the channel that are caused by the passage of cyclonic eddies through the region. These eddies, of radius larger than the channel's width and with their western edge against the Yucatan Peninsula, sometimes remain in the Bank's vicinity for several days before drifting northward. Although winds and wave-induced flow play secondary roles in the long-term circulation patterns, their influence increases during intense winter meteorological events, locally known as "Nortes".
DE: 4217 Coastal processes
DE: 4220 Coral reef systems (4916)
DE: 4560 Surface waves and tides (1222)
SC: Ocean Sciences [OS]
MN: 2007 Joint Assembly