Wecoma daily report, 9 August 2001

We completed our first BigBox grid at midnite on 8 August. We then turned offshore and followed the 50 fm (91.4m) contour from Line 8 to a line north (45 6.4N) of the Cascade Head line. We passed the Thompson as they conducted a time series of measurements at CH-3. We are presently occupying a SmallBox of Cascade Head, bracketing the CH line occupied by Thompson. Around 11pm tonite, we'll begin a CTD/zooplankton net tow transect from CH-7 to CH-1. We'll pass by Thompson again as they continue their time series at CH-3. The plan is to do MOCNESS zooplankton tows at CH-3 both at night and during the day.

We have posted results of our first BigBox on the COAST realtime results web site. These include vertical sections of T, S, density, chlorophyll fluorescence and ADCP E-W and N-S velocity. Maps of T, S, density, chlorophyll fluorescence and ADCP velocity were also posted. Cold, upwelled water was found inshore and extending offshore in the Heceta Bank region. Inshore on line 8 (Umpqua River) we saw the most intense upwelling with very high levels of nitrate, phosphate and pCO2. Silicate was high too, but not as high as the other nutrients, suggesting utilization by diatoms. A large pool of high chlorophyll was found on Heceta Bank (line 6) around 124.5W. We saw some water and chlorophyll coming off the Bank at its southern edge (line 8) and will target that for further investigation.

The ADCP sticks at 17m also show a prediction for the drift of a 12,000 gallon oil spill reported on Wednesday (8/8) afternoon 40 miles off Florence. The prediction was made by forming a streamfunction from the ADCP velocity sticks and then calculating the path of a fluid parcel. The prediction is based on 17m currents. Surface currents will be faster. (Note to Andy Dale: Steve Pierce and I can supply this psi-based prediction for the dye experiment based on our BigBox 2 occupation planned for this weekend.)

Winds are down below 10 knots from the NW and all sampling is going well.

Submitted 1800 on 9 Aug 2001 by Jack Barth, ChSci Wecoma