From: Wecoma Chief Scientist
Subject: R/V Wecoma report for 19-21 Jan '03

Wecoma departed at 1000 on Sunday 19 Jan as scheduled and proceeded with a visual inspection of the inshore ends of the five northern survey lines (1,A,B=2,C,3). The weather was beautiful and the seas calm. There was a considerable amount of crab gear from 50-80m on the inside of the southernmost line (line 3, closest to Newport and Depoe Bay), but less gear on the other lines. We decided to deploy SeaSoar and get started with a SmallBox North survey at about 1600 local. The CTD and bio-optics instruments on SeaSoar are working 100%. The SeaSoar vehicle as loaded is performing beautifully, sampling from the surface to around 140m and sometimes to 150m. This is great because we can reach much of the downwelled pycnocline near the shelfbreak. Thanks to the OSU Marine Technicians Marc Willis, Linda Fayler and Toby Martin! We are having ground loop problems with the conductivity sensor on MicroSoar. All other sensors on MicroSoar are working fine, sending up data via the fiber optic tow cable. Anatoli Erofeev is busy testing different combinations of the two sets of MicroSoar electronics that he brought along.

After completing line A and nearly all of line B of SmallBox North 1, we recovered SeaSoar, HTI and the iron fish and proceeded to do some deep CTDs at CH-5.5, 6, 6.5 and 7. This helps pin down the deep structure near the shelfbreak. From the CTD aboard SeaSoar we see a salty cold finger of deep water extending up the shelf on the bottom to about the 50m isobath. This feature is present in all the E-W sections, but there is considerable alongcoast variability in its structure. Perhaps this shoreward extension of deep water is the response to the recent week of good weather and upwelling favorable winds. At the surface from about mid-shelf (90m) toward shore, there is a fresh lens leaning up against the coast. The cold, halocline water documented for the summer of 2002 is still present at depth: 7.5 C, 33.0 salinity at ~100m.

At about noon on 20 Jan, the LDEO group (Roseanne Schwartz and Linda Baker) had the continuous underway iron sampling up and running. Prior to that they were taking discrete samples. Dale Hubbard is working hard to get the continuous pCO2 and nutrient systems on line. He had the nitrate channel running by midnight on 20 Jan. He has been in contact with Burke Hales and Leah Bandstra aboard Revelle and is continuing to debug the system. Tim Cowles has been collecting surface underway data from an ac-9, a chlorophyll fluorescence WETStar and a colored dissolved organic matter (CDOM) fluorescence WETStar. He is also filtering water samples for chlorophyll.

On 20 Jan we sampled SmallBox North 2 from south to north and completed all lines without incident. We then did a visual inspection of the inshore end of line 1 before launching SeaSoar/HTI/ironfish for a BigBox survey (lines 1-3). We sampled the offshore ends of lines 1 and 2 in the dark and worked through the crab gear closer to shore during daylight. It was especially challenging on the inshore end of line 3 given the amount of gear there. The captain, mates and crew continue to do a great job spotting and avoiding the crab gear.

We completed the 3-line BigBox survey and decided to do the deep CH-line CTDs (CH-10,9,8,7,6.5,6,5.5) while it's dark. The zooplankton group (Jesse Lamb and Jaime Gomez) are doing vertical net tows at these stations as well. This will take us through midnight on 21 Jan, after which we'll deploy SeaSoar/HTI/ironfish for a "ladder" survey (short E-W lines between the 100 and 150-m isobaths) along the downwelling front from south to north. We hope to learn more about the 3D variability of this feature.

We plan to do SmallBox North 3 in daylight tomorrow, but the increasing winds and waves could make that challenging. Winds have been 20+ knots for most of today and it's getting a little lumpy. We hope to get in our survey tomorrow as the system spins up with the big winds forecast. Our longer range plans are to complete a second BigBox (lines 1-3) and probably another SmallBox North to document the state of the ocean after the storm passes. We then promise the zooplankton group a MOCNESS/vertical net tow line along 45N.

Jack Barth
Chief Scientist, R/V Wecoma