HR: 11:05h
AN: OS52A-04    [Abstracts]
TI: Two Overflows in the Northern Gulf of California
AU: * López, M
EM: malope@cicese.mx
AF: CICESE, Depto. de Oceanografía Física, Km 107 Carretera Tijuana Ensenada, Ensenada, B.C 22860, Mexico
AU: Candela, J
EM: jcandela@cicese.mx
AF: CICESE, Depto. de Oceanografía Física, Km 107 Carretera Tijuana Ensenada, Ensenada, B.C 22860, Mexico
AU: García, J
EM: joaquin@cicese.mx
AF: CICESE, Depto. de Oceanografía Física, Km 107 Carretera Tijuana Ensenada, Ensenada, B.C 22860, Mexico
AB: Two overflows in the Northern Gulf of California are marked by strong average slopes of 15 and 5%. The long term (~ a year) average current at both sills is bottom intensified with average speeds of about 30 and 15 cm/s, respectively. At both sills there are strong tidal currents, but the low-frequency currents are quite persistent with very few flow reversals. Near-bottom stratification upstream (with respect to the overflows) of both sills is relatively strong, but downstream of the sills the near-bottom water is very well mixed and the bottom density is essentially the same as the one found at the sills, despite the almost two-fold (~ 600 m) and more than three-fold (~ 1500 m) increase in depth at the downstream basins. The homogenization of a thick bottom layer downstream, albeit close to the sills, is indicative of very strong mixing. These hydrographic patterns were observed during three different seasons. These results indicate that the deep water in Ballenas Channel is renewed by these overflows which enter at sill depths of ≤ 400 m and which are capable of reaching the deepest part of the basin at ~ 1500 m.
DE: 4243 Marginal and semi-enclosed seas
DE: 4512 Currents
DE: 4515 Deep recirculations
DE: 4553 Overflows
DE: 4568 Turbulence, diffusion, and mixing processes (4490)
SC: Ocean Sciences [OS]
MN: 2007 Joint Assembly