cruises were essentially identical, with the July calibration exhibiting a slightly higher slope.

Axial distributions of particle characteristics measured with the LISST on May 11, 2002 during a moderate ebb tide are shown in Figure 10.5. The salinity contours overlaid on each of the panels of Figure 10.5 provide a common reference frame, and illustrate several features of the particle distributions. May 2002 was wetter and delivered more sediment to the upper Bay than normal (Figure 10.2), in contrast to most of the rest of 2002, though this particular survey occurred before the largest pulse of fresh water inflow. As a result, the limit of salt intrusion was located at approximately km 25 and the water column was highly salt (hence density) stratified. A pronounced turbidity maximum was located near the limit of salt, with near-bottom TSS levels approximately 50 mgl-1 higher than background. Slightly elevated TSS levels were also apparent in the pycnocline stretching downstream from the limit of salt. Interestingly, this latter feature was not apparent in the data from the Sea Tech 5 cm pathlength transmissometer also located on the CTD frame (not used here). One of the most striking features of the LISST particle data was the high particle volume concentrations also concentrated in the pycnocline stretching downstream from the limit of salt. The only way that high volume concentrations can coincide with relatively lower TSS is if the particles are large, relatively watery flocs. This is confirmed in the D50 and pb distributions, where it is apparent that a large population

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