From: Pat Wheeler
Subject: Revelle Report 29 Jan - 1 Feb.
Correction to report below.
Russ caught an error in my description of the sequence of events below.
Our marathon surface/and bottom water sampling was on 28 Jan, i.e when the
SuperSucker was still working.
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Trials, tribulations and successes along the CH-line!
Late at night on 28 Jan, Burke Hale's pump system failed and during the next day
he tracked the problem to a failed (and unrepairable slip ring) which put the
Super Sucker out of commission. Meanwhile, on Wednesday (29 Jan) we completed
another Chameleon transect, with no chemistry or opitcs on line. During this
transect we collected carboys of bottom and surface water for a complete work up
of our organic measurements (POC/PON, DOC/DON, total nitrogen and phosphorus,
and the dissolved and particulate phosphorus). It was a real marathon for all
the water filterers aboard.
With Russ Desiderio's help we replumbed the chemistry and optics to use surface
water from the ship's uncontaminated seawater system. We started the 48-h time
series at 10:00 Jan 30 with Chameleon and surface optics and chemistry. The
times series was a huge success. Four bottom internal waves evident in the
Chameleon and Biosonics data. The bottom internal waves may have been roughly
related to the tidal cycle (observed at 8-12 h intervals). The Chameleon part
of the time series ended at 18:30 on 31 Jan when the currents became so weak
that the Chameleon was in danger of being pulled under the ship. We continued
the time series sampling for Ricardo Letelier's day/night transitions in Frrf
until 10:00 on 1 Feb. WECOMA stay in the vicinity during the time series to map
the small box around the CH-line.
Most of the water filterers on board got a well-deserved rest during the time
series. Ricardo's group continued with the pigments, absorption samples, and
PAM fluorometry associated with his frrf measurements and the other optics.
Kathleen Ruttenberg (our COAST collaborater working on phosphorus) was on board
with her group from WHOI, needed to return to land to deal with a family
emergency. With Rick Berlini's help from the WECOMA, we were able to contact a
local fisherman and arrange a personnel transfer with short notice but a very
speedy response. The Misty left Newport at 08:00 Saturday morning and reached
us at CH-5 at 10:00. We were blessed with pretty calm weather and two of the
Revelle crew members took Kathleen and her gear over to the Misty in the the
Zodiac in two speedy trips and the whole maneuver was completed in less than 20
minutes.
On 1 Feb with the res tech's and computer techs' help we pulled out the CTD
rosette and did water collections at CH-2 for Mike Wetz's incubation experiments
and Ricardo's 14C incubations. Mike is collecting bottom water samples and
running incubations at different light intensities to examine light requirements
for near-bottom seed populations to start growing. In his first two incubations
phytoplankton exposed to high and medium light intensities started growing
within 2 days. His first two incubations reached stationary phase within eight
days and were then terminated. He should have a very nice series of experiments
with estimates of phytoplankton growth rates and final yields as a function of
light intensity.
During the afternoon we started another Chameleon transect from CH-1 to CH-6.5.
For this transect we ran the ship's uncontaminated seawater through the
chemistry and optics lines and filled carboys every fifteen minutes in the low
salinity water and across the inshore surface salinity gradient and at less
frequent intervals afterwards. This should give us a very nice data set for
comparing characteristics of the organic material in the fresher water and
seawater.
We are using the night hours to contiue bottom (multibeam) mapping along and
across the CH-line. Jim started some of this during the 2001 cruises and hopes
to complete it at least as far out as CH-5.
On 3 Feb we started another Chameleon transect, again with chemistry and optics
set up for the uncontaminated surface water and filling carboys for discrete
measurements of particulate and dissolved organic material and Ricardo's pigment
and other photochemical measurements. The low salinity water has moved further
offshore so this will be a nice comparison with the previous transect.
Weather predictions look good for the recovery of Jim Moum's bottom mooring
(lander) as the main activity for 3 Feb.
We are delighted with the amount of work that we have been able to complete and
the exiciting results that we continue to get. Thanks to WECOMA participants
and all land-based COASTers for the continued stream of results sent through the
COAST web page. We have the walls of the Revelle passage way decorated with Sea
Soar, CODAR, met data, SeaWifs, and satellite SST images.
Pat Wheeler
Chief Scientist, RV Revelle
2 February 2003
