Salinity and Velocity in Lower South San Francisco Bay

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.