19 July 2008 R/V Wecoma cruise - Estuary South Channel

Overnight last night we anchored in the North Channel near the Saturn 01 station and cast the CTD hourly until the morning. We then moved to the south channel to begin a day of CTD casts with the goal of following a specific salinity bottom water (~15), up and down the estuary. We were guided by Joseph Zhang at OHSU who provided way points and times. For most of our casts the surface water was saltier than predicted, and the bottom water was fresher than predicted, suggesting that the forecast model is not capturing the degree of water column mixing. We also conducted many cross-channel surveys, casting the CTD at three points across the channel in a reach of the South Channel between the AM Bridge and Tongue Point. Cross-channel variability was greater than expected, with more stratification on the south side of the channel, and less stratification on the north side of the channel. We cast the CTD a total of 30 times in the south channel before heading back to our nighttime anchor station in the North Channel.