Thompson Cruise Report August 21-23

On August 21 we started our southernmost profiling transect along 43 51.5 in the westward direction. With the wind and currents, Burke's pump was close to being pulled under the ship and we could not complete the transect in this diretion. We transited to the offshore end and were able to complete the profiling transect in the eastward direction. On August 22 we repeated our series of transects from 43 56.5 N to 44 16.5 N (with ADCP only) across the high offshore chl and the jet to verify the location of the jet, then we did a N/S profile along the core of the jet from 44 16.5 to just past the southern edge of Heceta Bank. Chemically and biologically the structure along the jet was similar with a subsurface chl max of 0.3 to 0.6 v Fluor. We took samples from the chl max every two hours for pigments, POC/PON, extacted chl and DOM. As expected there was increased turbulence over the southern edge of the bank. We completed the N/S profiling transect at midnight then headed north for profiling across Stonewall Bank along 44 33 N.

We started the Stonewall Bank profiling transect at 06:30 (Friday August 24) and should finish the E/W profiling at about 14:30. The inshore water is high in Chl (about 3 v) and most of it is < 10 um. This is in contrast to previous sampling where most of the high Chl was chain forming diatoms > 10 um. There are also a lot of gelatinous zooplankton in the surface water here.

After completing the E/W profiling (44 33 N 124 15 W to 44 33 N 124 30 W), we plan to transit to 44 18 N 124 24 W and then profile from there back to 44 33 124 15 W. This last profiling transect should start around 17:00 Friday and may take about 10 h if we profile the entire line. If we can coordinate plans with WECOMA we will try a comparison of ISUS and Burke's profiled nitrate in the vicinity of 44 33.0 124 15 W.

Afterwards we will transit to NH 25 to deploy the last two drifters before noon on Saturday.

Pat Wheeler
Chief Scientist, Thompson