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Date: Thu, 6 Oct 1994 11:34:01 +0000 (GMT)


We are at the end of the intercalibration and training cruise, and are
pleased to report that everything has gone very well.  The ship's crew and
scientists have worked hard to solve problems as they arose and most
systems have been thoroughly "wrung out".  High quality, edited data is
available from 24 stations (46 casts) as we leave the ship and copies will be
forwarded to the chief scientists of each U.S. JGOFS leg within the
next month to aid them in planning their cruises. There are three
Seabird CTDs aboard, two with dual sensors, two 24-bottle Seabird
carousels, and back up General Oceanics rosettes.  All sensors and
cable have been used in 4000 m casts.  The hydro team (CTD, salinity,
oxygen, nutrients) has been generating superb data, cross checking for
consistency, and developing protocols that will be used on all
subsequent U.S. JGOFS cruises. A protocol manual is being written which
will be distributed for your comments soon.  The aft conducting cable
(.68) worked flawlessly on 11 MOCNESS tows.

We have internet connectivity at a cost of $1 per 1000 characters.  The
ship has many computers linked by ethernet; the science computer has
three years of TOPEX data (10 day composites) for the region, and three
years of model output from Mark Luther (monthly averages).  These were
brought out and installed by John Morrison.  The ship's acoustic
Doppler current profiler is being configured by Charlie Flagg to
operate autonomously, displaying the standard ADCP profiles each 5
minutes and also displaying cumulative 12 hour plots of current and
range corrected backscatter intensity.  Charts, reprints, and atlases
reside in the science office.

Lou Codispoti plans to send preliminary copies of the bottle data to
the chief scientists of each leg within the next month.  These data
were collected at 24 stations beginning at 8 deg N, 65 deg E and
continuing along the eastern and northern portions of the U.S. JGOFS
cruise track into Muscat.  The hydro team has intercompared standards
from SIO/ODF, Old Dominion Univeresity and the National Institute of
Oceanography in Goa, India, with excellent results.  Comparisons of the
SIO/ODF automated Winkler titrations with a colorimetric method
optimized for low concentrations produced excellent agreement
(+/-0.003ml/l) down to concentrations of about 0.015 ml/l.  Wajih Naqvi
and Ted Yoshinari collected data on nitrous oxide and its isotopic
composition, and other isotopic data (in collaboration with M. Altabet)
with support from the ONR-managed bi-lateral USA/India program.

The trainees from Oman and Pakistan have provided much needed
assistance.  A series of seminars presented by S. Smith, G. White, J.
Morrison, C.  Flagg, L. Codispoti, T. Yoshinari and W. Naqvi was
organized for their benefit; most of the scientific complement and some
of the ship's crew attended.

The system for automatic ADCP data collection has been installed and
has been enhanced to show the previous 12 hours of velocity and
backscatter data in real time.  The installation of the ADCP on the
Thompson generates superior results throughout the ship's speed range.
ADCP highlights include a remarkably clear indicatiion of equatorial
waves along 5 deg N, east of 80 deg E, currents in the central Arabian
Sea that resemble Luther's model output from October 1993, and vivid
pictures of the diel plankton migration.  The range of the ADCP in the
Arabian Sea varies with location and time, being about 400 m during the
day, even in the low oxygen region, and decreasing to 200 m during the
night when the plankton migrate to the surface.  We used the MOCNESS to
investigate the layer that resides in the low oxygen region in the day
and comes to the surface at night; the preliminary impression is that
it is composed of euphausiids and myctophid-like fish.  There are areas
in the low oxygen region where there appeared to be nothing, judging by
the ADCP's backscatter, and these layers did indeed seem to be devoid
of "ordinary" plankton.  We also found the animals that dominate the
Somali upwelling area (Calanoides carinatus) present in the areas where
phytoplankton was more abundant.  These areas are consistent with our
understanding based on CZCS images.

A vexing problem with excessive noise in some of the CTD casts remains
to be completely resolved, but it had only a minor effect on the
quality of the data.  Work on this problem continues and we expect it
to be solved by the first U.S. JGOFS process cruise in January.  The
intercalibration and training cruise has achieved its goals and heads
for Muscat satisfied.  Winds were never above 14 knots and the seas
were calm for 21 days.  The sun shines without mercy.

Sharon, Lou, John and Charlie