Slide 1

Studies of Estuarine Hydrography Originally: Environmental Studies for sustainable management of two bays of semidesertic climate: El Tobari y Lobos, Sonora, Mexico. Now: Environmental Studies for sustainable management of a bay of Semidesertic Climate: El Tobari. Esther Cruz-Colin, Juan Antonio Delgado, Arnoldo Valle-Levinson, & Stephen Monismith Slide 2 Objective Complete hydrodynamic behavior and physical and chemical characterization for El Tobari and Lobos, two coastal lagoons/estuaries, with the purpose of giving a solid basis for their management and sustainable development (or restoration). Slide 3 Specific objectives Implement periodic monitoring in both lagoons to detect changes in physical conditions (salinity, circulation,..) which may be important for nutrient cycling, larval transport etc. Develop first picture of how circulation patterns in these shallow estuaries respond to winds, tides, and evaporation - typical for desert-climate coastal lagoons Develop data needed to model these systems Slide 4 Mean = 1.2 cm/s Mean = 2 cm/s North Mouth South Mouth January 2000 data antecedents Slide 5 January February 2000 antecedents Slide 6 February January 2000 Moored south mouth Slide 7 Work to date We carried an intensive field experiment at each of the mouths of the Tobari in which we measured salinity (CTD) and velocity (ADCP) transects throughout a 24 hour period using small boats. Additionally we collected time series of salinity, temperature and depth for one month periods at both mouths. Slide 8 Us schedule of measurements Paredon Colorado Tonys roof Slide 9 The transect boat ADCP gps Laptop for real time tools amarre Slide 10 Camp Tecate Slide 11 Captains Chuy and Peter Slide 12 It takes a village to launch a boat.. Slide 13 The buoys were easier to see in the daylight Slide 14 The iron men Slide 15 Boca norte Boca sur Bathymetry (done with ADCP/GPS) Slide 16 Bathymetry Slide 17 Wading birds near Boca Norte Slide 18 October 2002: Boca Norte Transects 1 2 3 4 Slide 19 Transect data analysis Harmonic analysis (least squares) to extract mean flow, M2 (semidiurnal) and K1 (diurnal) tides from transect data Look for spatial variability of flows Slide 20 Mean velocities: Transect 1 Out In Transverse variability important for fluxes Slide 21 Tidal velocities: Transect 1 Slide 22 Mean velocities: Transect 2 Slide 23 Tidal velocities: Transect 2 Slide 24 Mean velocities: Transect 3 Slide 25 Boca Sur transects: March 2003 Wavy! (muy peligroso) 3 4 2 Slide 26 Mean velocities: Transect 3 Slide 27 Tidal velocities: Transect 3 Slide 28 Slide 29 A front in the south mouth Slide 30 Manuel manually does the CTD Slide 31 Temperature (C) Salinity (ups) ebb flood end ebb start ebb start flood Slide 32 Summary The patterns of circulation are predominantly tidal Are mean currents (and exchanges) produced by rectification (bathymetry is crucial) or by variations in density (or both)? Slide 33 Next steps: Finish processing 2002/03 data More field work in El Tobari South Mouth Integrate with Mikes nutrients and phytoplankton work 3D model of El Tobari (remove causeway!) Lobo (harder logistically) New NSF proposal (see next talk) Slide 34 The good news is To continue this project and to accomplish the specific objective for this studies we will get funds from Consejo Nacional de Ciencia y Tecnologa (CONACyT)- Secretara de Medio Ambiente y Recursos Naturales (SEMARNAT). amount: $413,816.00 pesos = $35,984 dlls