We determine the concentration of suspended solids in the water column using a submersible Optical Backscatter Sensor (OBS). The OBS operates by sending a beam of infrared light into the water, the beam is scattered by suspended particles and the OBS then measures the quantity of light that is reflected back to its sensor. The instrument is calibrated each sampling date by comparing the OBS values to collected water samples. We filter the water samples onto pre-weighed filters and re-weigh the filters after they are dried, the difference in weight is due to the suspended solids. This plot shows the agreement between the discrete (collected) suspended solid concentrations and those calculated from the OBS. The points on this plot represent all the measurements made in South Bay during 1996. The average deviation between calculated total suspended solids (TSS) from the OBS and measured/sampled TSS is 2.2 milligrams per liter, equivalent to a mean error of 8%.

See examples of TSS vertical profiles.