HR: 14:50h
AN: OS33C-04    [Abstracts]
TI: Tidal and Wind Driven Circulation at Huatulco Bays and Water Quality
AU: * Reyes-Hernandez, C A
EM: creyes@angel.umar.mx
AF: Universidad del Mar, Ciudad Universitaria, Puerto Angel, Oax 70902, Mexico
AU: Mayorga-Adame, G
EM: ocean_gb@hotmail.com
AF: Universidad del Mar, Ciudad Universitaria, Puerto Angel, Oax 70902, Mexico
AB: ADCP and CTD observations performed from April 2005 to October 2006 as well as the numerical model ROMS were used to describe the circulation inside of Huatulco Bays in Oaxaca, Mexico, and asses the potential impact of the resulting transport. Tidal and residual circulations show strong dependence on the morphology of the continental shelf. To the west of Huatulco Bays, the continental shelf narrows to almost disappear. Different 25- hours velocity averages along the year collected at the entrance of the bay system show velocities around 20 cm/s to the southwest; at the interior of the system however, circulation consists mainly of eastward velocities about 14 cm/s. This pattern suggests that subtidal circulation within the bays is composed by an inflow by the western side and outflow by the eastern side. Consistent with observations, numerical experiments considering the M2 and K1 tidal components show that off the bays, though the tidal wave propagates to the west, circulation in the interior has a general orientation to the east. It is proposed that the crowding of the isobaths and the tidal wave propagation to the west of Huatulco results in a water piling and in consequence a recirculation to the east in the interior of the bays system. This type of circulation is similar to that in response to NW and SW wind, but not to that driven by wind from other directions. According to this picture, relatively diluted water from the Copalita river, 5.5 km to the east of the bays, is a source of surface water into the bays and probably an important factor for its quality. Water quality parameters collected inside of the bays during 2005 met the criteria for recreational use, except at very located points at the beginning of the rainy season, indicating no relationship with water from Copalita river.
DE: 4217 Coastal processes
DE: 4235 Estuarine processes (0442)
DE: 4546 Nearshore processes
SC: Ocean Sciences [OS]
MN: 2007 Joint Assembly