27 July 1998 09:11:34
We departed Gulfport 25-July-1998 10:43 PM local time
after completing calibration of new Ashtec 3DF at dock Sat evening. We
deadheaded all nite with ADCP and SAIL logging sfc temp and salinity. Very
low salinity water at 10 AM local time Sunday morning, at 29 20N, 87 32W
(to 24 psu); headed toward first CTD station (test station) in DeSoto Canyon.
ETA there about 11:30 AM local time. All systems working OK.
27 July 1998 09:11:45
We're on station N2L10S21X at 07:30 AM local today
Mon 27 July. Salinity along 1000 m isobath was:
Tue, 28 Jul 1998 13:10:10 -0500
We finished Line 11 at 6:50 CDT time this morning. Surface salinities were higher over the shelf off Tampa (where currents had a component coming from the south) than those <32 psu over the slope and deep water (where currents were coming from west and north). The warm core eddy has apparently entrained a large amount of freshwater in its northern margin and this low salinity water is probably going to be the norm over most of the area we're going to survey from here on. Our 7 AM position is 27 30.3N, 87 52.0W All instruments working except for irradiance meter from USF. The USF guys forgot a key cable that goes to masthead sensor (they brought the wrong pin config) and a small boat from USF is going to rendevous with us later today as we pass close off seabuoy at entrance to Tampa Bay and bring this out to them (no cost to NEGOM and no waiting; they will come to us). Bird and mar mam observers had a good day yesterday as we transited from slope on to shelf.
(I think he must mean 6:50 UTC and 82 52.0W ) ( Matt Howard)
Norman Guinasso reports by satellite telephone that the
GYRE recovered a U.S. Airforce drone. Red, 20 feet long, jet
powered, instrumented, and in great shape. Apparently it was launched
from Tindale AFB and they are sending someone out to pick it up!
Wed, 29 Jul 1998 15:46:02 -0500
At 8:30 AM CDT, we were on the 500 m station on Line 10.
No problems with stations done along this line; altimeter has been repaired
by swapping parts between the two available instruments. We will deploy
first ALACE float of this trip at the seaward end of this line. We're
back in low salinity again (29.7 here at sfc) as we approach deepwater;
salinity at surface over the shelf was 34-35 psu. No sperm whales
seen yet but yesterday observers saw groups of dolphins and seabirds.
Wilf, Cheryl says that mooring came up fine and all instruments recorded
data. doug sends
Date: Wed, 29 Jul 1998 17:59:08 -0500
We have completed lines 10 and 11 and are starting line
9. We detoured about 5 miles past line 10 to deploy a PALACE float.
One of our altimeters is broken and the other is not
working well; I bought another and it hopefully will be brought out by
Air Force boat when they recover their aircraft Friday. Wish you were here.
fishing report: Towed 5 big game lures for 5 hours.
No fish.
Cruise Report for 30 July 1998
Date: Fri, 31 Jul 1998 16:03:50 -0500
At 7:30 AM CDT we're at 28 43.9N and 85 52.3W, coming
up on Station N3L09S07C. Weather fine but we're keeping an eye on
Tropical Storm A even though it's still 2600 miles away, in central Atlantic.
Steve asks if you have any update info on SAIC mooring rotation cruise
(to start around 4 Aug)? Bob Albers ordered replacement altimeter and will
send it to Panama City for us to pickup Sat when we come close offshore
there. Can you try again to fax us SSH anomaly map for NE Gulf that you
overlay with our NEGOM lines? Last map we have is for 23 July.
All else is fine(except the fishing).
Cruise Report for Fri 31 July 1998
Date: Fri, 31 Jul 1998 16:04:33 -0500
We're working Line 8 today. Started 1 AM CDT inshore and at 14:30 local we're on N3L08S11C. Air Force delivered replacement altimeter when their boat met us just after 6 AM CDT to pick up the jet drone we had recovered for them. All equipment working; no problems to report. We're still encountering low salinity river water at the seaward ends of each line. Thanks for faxing us updated SSH anomaly map.
(No reports received Saturday or Sunday 1-2 August 1998)
Cruise Report for Monday 3 August 1998
Date: Mon, 3 Aug 1998 17:57 -0500
We have completed lines 11 through 5 as of 18:00 8/3/98 local time. We have had no significant problems.
In addition to the planned work, we have deployed 5 PALACE floats as follows:
End of line 10 ---- 2 floats at 1000m and 1500m
End of line 8 ---- 2 floats at 1000m and
1500m
End of line 5 ---- 1 float at 1475m
We have also done two daily light meter lowerings each day.
We are recording each second the heading, roll, and pitch from the Ashtech ADU. Steve has done some spectra of these data. The roll and pitch show a peak at about 6 seconds, which we assume to be the natural roll of the vessel. The heading data show a peak at about 3 minutes that we attribute to the autopilot.
The ring feature seems to produce a wide band of fresh water originating at the Mississippi Delta. The water is swept around to the area off Tampa. The coastal waters have high salinities but as the line progress offshore the salinities drop to very low levels. On a few of the lines we penetrate past the low salinity water into more normal high salinity waters in the deeper waters. We have noticed no very low oxygen values.
We have had to re-terminate the CTD wire when the outer layer of the wire broke above the strain relief. The wire appears rusty and brittle and should be looked at carefully before the next NEGOM cruise.
We lost a day of differential GPS yesterday due to widespread thunderstorms in the area.
Both altimeters stopped working but we made one working one out of parts from each. I bought a new altimeter (not charged to NEGOM) which was brought out to the Gyre on the Air Force boat. We have installed the new altimeter on the CTD and it is working much better than the old one.
Up until yesterday the weather was very benign. We had high seas today with much rocking and rolling.
We are about 5 hours behind the 8 knot schedule and expect to be in port between 2 am and 8 am Saturday.
Biggs and Guinasso
Cruise rpt for 4 Aug
Date: Tue, 4 Aug 1998 14:59:06 -0500
We're on Sta 10 on Line 4 at 7AM CDT (29 22.5, 87 20.1). We've deployed 17 ARGOS drifters so far, as scheduled, and 5 profiling ALACE drifters. We expect to finish NEGOM lines by midnite Wednesday or early Thursday morning, then go to Miss Canyon to put in mooring, and then back to Galveston at or before dawn on Saturday. New altimeter is working well (picking up bottom some 40 m above bottom). No problems to report. We've made 7 plankton tows so far and have 7 more to complete at SAIC mooring stations. Bird and MarMam observers seeing lots of their targets in and near freshwater flow around warm ring.
Subject: Cruise rpt for Wed 5th
Date: Wed, 5 Aug 1998 18:11:29 -0500
We just finished 1st station on Line 2 at 7:45 AM local and will work seaward on this line today. After finishing this line at 1000 m water depth we plan to drive farther offshore and deploy PALACE drifter in about 1500 m water depth, then head to Line 1 and finish this final series of stations to end just off Miss Riv delta about midnite tonite or early tomorrow morning. From there to Miss Canyon to deploy mooring for Cheryl, deploy final PALACE drifter in deepwater Canyon, and then deadhead to Galveston. ARGOS drifter deployment proceeding as planned (we have 6 left to put in); no problems with science equipment.
Subject: Cruise rpt for Thurs 8/6
Date: Thu, 6 Aug 1998 09:04:39 -0500
We finished final NEGOM station at 6 AM CDT this morning, ending CTD work just off Miss River delta. We're now on our way to Miss Canyon where we'll deploy mooring for Cheryl Burden. Vis observers have seen whales, dolphins, and seabirds and will continue obs as we deadhead back to Galveston. USF guys and I are pleased with concurrent logging of chl fluorescence and DOC fluorescence; the two correlate quite well for most of the NEGOM field area but there are some interesting exceptions.