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Salinity and Velocity in Lower South San Francisco Bay


Hoang, Olivia (2019), Salinity and Velocity in Lower South San Francisco Bay, Dryad, Dataset,


In order to measure salinity gradients in the longitudinal, lateral, and vertical directions, a mesh of nine Ruskin RBR XR-420 CTDs and two Seabird SBE-37's were placed in various positions in all three dimensions. Lines 1, 2, 3, and 4 were placed in the channel. Lines 5 and 6 were placed in the shallows, lateral to line 2. Line 1 has two CTD's attached at the top and bottom of the water column. Lines 2 and 3 have a top, middle, and bottom CTD. Line 4 has one CTD located near the surface of the water column. Lines 5 and 6 each have a Seabird attached at the surface of the water column. The RBRs and Seabirds measured conductivity, pressure (depth), and temperature, and calculated salinity, at one minute intervals. The RBR XR-420 CTDs (Seabird SBE 37s) have a temperature accuracy of  +/-0.002 deg C and pressure accuracy of 0.05%.
Two Teledyne RD Instruments (RDI) 1200 kHz Workhorse Monitor Acoustic Doppler Current Profilers (ADCP) were deployed at locations 2 and 3, and were tethered to the CTD lines by a bottom cable. The moored ADCPs were programmed to measure over a 12 meter water column with a vertical resolution of 0.25 meters with the first bin located 0.81 meters from the sea floor. The ADCPs, like the RBRs and Seabirds, collect ensemble averages every minute.

Usage Notes

      Average Depth [m]   NAVD88 Bathymetry [m] Mean Water Depth [m]
Line Latitude/Longitude Top CTD Middle CTD Bottom CTD ADCP
1 37.48775 -122.08939 2.4 - 7.3 - -6.52 7.50
2 37.47754 -122.07643 2.7 6.7 9.8 x -9.48 10.46
3 37.472 -122.06679 1.0 4.1 6.0 x -4.68 5.66
4 37.45979 -122.03996 0.5 - - - -0.35 1.33
5 37.47415 -122.09045 1.0 - - - -0.47 1.45
6 37.48185 -122.06825 0.6 - - - 0.12 0.86

Mooring Detailed Locations and Water Depths. Each CTD measures depth below the water surface. Here we display the average depth that the CTDs measured throughout the deployment. The column labeled NAVD88 provides the referenced depths from a Lower South Bay bathymetry dataset collected by the San Francisco Estuary Institute (SFEI) available on their ERDDAP website. The water depth at each mooring is estimated by taking the difference of the MSL at Alameda (0.98 m from NOAA Tides and Currents) from the NAVD88 bathymetry.


San Francisco Bay
San Francisco Bay
San Francisco Bay
San Francisco Bay
San Francisco Bay
San Francisco Bay