From: Wecoma Chief Scientist
Subject: Wecoma report for 22-23 Jan '03

COAST R/V Wecoma report
22-23 January 2003

It was pretty exciting out here on Wednesday, 22 Jan, with strong winds from the southeast. It blew a steady 30+ knots with sustained gusts to 35 and sometimes 40 knots. Seas built to 18-20'. We started a SmallBox North survey around 10am and were rocking and rolling in the trough as we sampled east-west on line A off Hart's Cove on the northern side of Cascade Head. Our launch point there is spectacular. The cliffs of Cascade Head looming over us and waterfalls pouring into the seas with big swell crashing on shore. As we sampled back to the west with the wind blowing 30-35 knots, seas 18-20' and the Wecoma taking 30 degree rolls we made the decision to not go inshore of the 100m isobath in this weather. We couldn't risk getting hooked up on any crab gear in this weather. So we finished the SmallBox North by sampling lines B and C offshore of 100m. With winds building even more we recovered all the sampling gear (SeaSoar, HTI bioacoustics sled and the iron sampling fish). The SeaSoar recovery was epic, with waves crashing through the A-frame and sweeping the fantail. The OSU MarTechs and science crew did a great job getting the gear on board safely. Thanks to Marc, Linda and Toby!

We spent Wednesday night doing ADCP transects along the Cascade Head line, getting in two realizations before daybreak on Thursday. Steve Pierce's plots of ADCP velocity showed northward currents over the shelf with maximum values at 17-m depth of 60+ cm/s (1.2 knots) centered over the 70-m isobath. The northward velocity dropped to zero quite dramatically at the shelfbreak, forming a region of strong horizontal shear around the 150-m isobath. We're getting exactly the experiment that we wanted: strong southerly winds and the tools to document the oceanic response.

We all thank Doug Capps (Cook) and Doug Beck (Asst Cook) for preparing a great dinner even when the Wecoma was going through those 30 degree rolls!

It was nice to see the Revelle back sampling on the CH line late Wednesday night after their successful port stop in Newport. I wonder how the ride is over on Revelle?

Dale Hubbard got the pCO2 system running on the underway 5-m flow-through line by bypassing his tempermental pump and just using the ship's flow-through pressure.

As of Thusday morning, winds have dropped dramatically to 15-20 knots and we're just finishing Line A before continuing on with lines B and C during the daylight. The line A hydrographic and bio-optical fields from SeaSoar show a strong downwelling signal near mid shelf. The deep, salty cold near-bottom water is being shoved down along the slope and offshore.

We plan to keep sampling on the SmallBox north and BigBox lines 1-3 for the next few days. We'll probably pick up some deep CTDs along the Cascade Head line (CH-5 to CH-7) at night. Winds are expected to pick up again tonite and we'll still have downwelling favorable winds through the weekend.

Jack Barth
Chief Scientist, R/V Wecoma
1100, 23 Jan 2003