9:45 a.m.:  SeaSOAR continues this morning on the last east-bound line of the mesoscale survey.  This morning an expendable bathythermograph (XBT) was deployed.  The XBT consists of a weight pulling a thin copper wire off a spool as it descends into the water.  As the weight descends at a known rate (1,000 meters in 2 minutes and 45 seconds) it sends temperature readings back to the ship.   From this data, a depth versus temperature profile can be determined.  Several XBTs will be deployed during this cruise.  Computer technician for the Revelle, Bill French, is shown deploying the XBT.

We have started a Science Team Participants page that will be updated as the cruise continues.

2:30 p.m.:  Today's Chief Scientist Report

We have successfully completed lines 10 (Rogue River) and 11 of the
Mesoscale grid and are eastbound on line 12 (Crescent City). We expect to
complete the survey inshore at 12E at around 8pm Tuesday evening. Spirits
are high on the R/V Roger Revelle and the cooks, Ed and Stacey, continue
to serve us great food. Last night we had lamb chops and freshly caught
albacore tuna in a pineapple lemon sauce. Excellent!

The SeaSoar and HTI bioacoustics sampling on line 11 delineated the
southern end of the cyclonic (counterclockwise) circulation feature that
is centered at 125 35'W, 42 40'N. That "eddy" has lots of surface
chlorophyll with values as high as observed over Heceta Bank. The
presence of warm water, phytoplankton and zooplankton at depth (in excess
of 100 m) on the westward edge of the cyclonic-turning jet occurs most
strongly on lines 8-10, with just a hint of it on line 11. This cyclonic
feature is very intriguing and we will investigate it further on Wednesday
(see plans below).

We did complete a "flyby" of New Horizon on the inshore end of line 10 and
perhaps will do one last one somewhere on line 12 when we cross paths with
New Horizon working its way westbound. The inshore end of line 10 had
enormous numbers of jellyfish. Over the outer shelf, they were a white or
pale blue color without tentacles and the New Horizon scientists told us
they were "Aurelia Labiata." Farther inshore, these were joined by
another species of jellyfish, brown or yellow in color with tentacles.
We'll wait to hear from the jellyfish experts on New Horizon to identify
this species.

The top trophic group (Cyndy Tynan, David Ainley, Tom Ryan and Chuck
Alexander) continue to do line-transect surveys of mammals and
strip-transect surveys of birds for 12-14 hours each day. They're
constantly vigilant during daylight hours, except for short breaks for
meals. On line 10 yesterday, they observed the following mammals (# in
parentheses): Dall's Porpoise (18), Humpback whales (6), Harbor porpoise
(11), Elephant seals (10), Fur seals (2), Stellar Sea Lions (2),
California Sea Lion (10) and Harbor seals (5). As far as birds, in waters
of the slope and deeper (warm water), they observed Leach's storm petrels
and a major southward migration of Red Phalaropes, Arctic Terns, and
Long-tailed and Parasitic Jeagers. In waters within 10 miles of the coast
associated with the cold alongshore upwelling front they observed Common
Murres, Pink-footed and Sooty Shearwaters, Cassin's Auklets, and
Red-necked and Red Phalaropes.

After finishing the Mesoscale grid at Crescent City, we will turn to the
northwest and tow SeaSoar and the HTI to find the center of the cyclonic,
chlorophyll-rich feature. We expect to pass through the eddy around 42
40'N, 125 35'W around 0800 PDT on Wednesday. We'll then spend a few hours
fine-tuning our estimate of where the eddy center is. Around noon we'll
start a series of five stations in and E-W line across the eddy.
Nominal locations for these stations are along the 42 40'N line: 126
4', 125 50', 125 36', 125 22' and 125 8'. The
middle station will be in the center of the eddy, two will be on the edges
of the eddy and two will be farther away (hopefully outside) the eddy. We
hope the "edge" station on the western side will contain the deep plankton
feature that we observed during the Mesoscale survey. Each station will
consist of a 1000-m CTD/rosette cast during which we'll collect water
samples for chlorophyll and nutrients. Water from the cast in the deep
plankton feature will be used for a C14 phytoplankton growth experiment.
The bio-optics package will be used on two stations, one at the eddy
center and one in the deep plankton feature. Bill Peterson says that the
New Horizon will join us in the eddy after they finish net sampling on the
Crescent City line. After completing the stations around midnight on
Wednesday, we'll transit north at full speed to begin our sampling around
Newport.

One challenge that the Scripps computer tech Bill French is working on is
intermittent failure of the Knudsen echosounder. We cannot fly SeaSoar
safely in shallow water without good bottom depth information. The
failure seems to be temperature dependent and Bill is in contact with
engineers back at Scripps about how to solve the problem. As a backup, we
ran the Simrad multi-beam echosounder system this morning and it did not
appear to interfere with the HTI bioacoustics package. So we can use
depth information from the Simrad to fly the SeaSoar. Bill is working on
coding up a piece of software that will make the Simrad output available
to our SeaSoar flight controller. One bonus is that the detailed bottom
characteristics from the Simrad can be shared with geologists at OSU and
HMSC to improve their characterization of the bottom habitat off Oregon.

---Jack Barth, Chief Scientist R/V Roger Revelle
filed 1430 PDT August 6 2002

3:00 p.m.:  We are approaching the end of line 12 and another rendezvous with the New Horizon.  As we get closer to the coastline, the smoke from the southern Oregon forest fires is plainly visible as a thick brown layer.

8:00 p.m.:  Winds and seas have picked up a bit and we are under the smoke that extends well out to sea.  It made for a spectacular sunset this evening.

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