HOT-32: Chief Scientist Report

Chief Scientist: C. WINN

Personnel list:
  
       Chris Winn - Chief Scientist 
       Jean Pietrazek
       Dale Hebel             
       Dan Sadler              
       Elaine Kotler           
       Florence Thomas    
       Terrence Houlihan
       Ken Constantine
       Ilse Hamann
       Jim Christian
       Louis Tupas
       Richard Muller
       Sheryl McCarthy
       Hongbin Liu

Itinerary (local time):
  
  Wednesday, Dec. 4
      1030     left Snug Harbor
      1300     arrive Kahe Pt.
  Thursday, Dec. 5
      0400     arrive Station ALOHA
                deploy sediment traps commence CTD operations
  Friday, Dec. 6
      1800     suspend CTD operations
  Saturday, Dec. 7
      0600     commence CTD operations
      0200     recover traps
      0400     begin transect
  Sunday, Dec. 8
      2300     complete Station 5 transit to Snug Harbor

Cruise Brief

     We left Snug Harbor at 10:30 after an approximately 40 minute
delay to complete the hydrowire termination and to complete securing
loose gear.  The weight test, the light cast and the 100m cast at Kahe
point were completed without incident.  Because we had few experienced
crew on HOT-32, Dale Hebel briefed the entire science party on proper
water sampling procedures, especially for oxygen and nutrients, at Kahe
Point. Although this caused a delay of approximately 15 minutes in
completing the sampling of the rosette at Kahe Point, the exercise
proved useful, and we had few sampling problems on subsequent casts.

     Upon arriving at Station ALOHA the sediment traps were deployed on
the southeast edge of Station ALOHA, and CTD operations we commenced
after transiting to the center of the Station. The in situ primary
production array was deployed and recovered without problems.  CTD
operations were suspended because of moderatelyrough weather at 1800 on
Friday the 6th. CTD burst sampling on HOT-32 was therefore restricted
to approximately 30 hours. The sediment traps were recovered 72 hours
after deployment. The sediment trap array drifted only a few miles on
this cruise.

     CTD stations 3, 4 and 5 were occupied on 158oW at 23o 25'N, 21o
57.8'N, and 21o 46.6'N as on HOT-31.  XBT's were dropped at regular
intervals during the transit from Station 3 to Station 5. Water samples
were drawn for nutrients, chlorophyll and salinity at each of these
stations. In addition, the flash fluorometer and the transmissometer
was deployed on each of these casts.

     The ship proceeded along the 300m isobath from Station 5 to
Kahena Point, to provide for calibration of the ADCP. Between Kahena
Point and Snug Harbor the ship moved several miles offshore to pump the
bilges. We arrived at Snug Harbor at approximately 0730.

Problems on HOT-32

     CTD operations were somewhat disorganized on this cruise.  For the
most part this appeared to be due to Jef Snyder not being present on
this trip.  There was quite a bit of confusion about which
configuration file to use for individual casts.  It would probably be
useful to have a set of written CTD operating instructions in case core
personnel are unable to participate in a particular cruise.

      We had the choice of using the stern A-frame or the
non-articulated crane for deploying the CTD on HOT-32.  Because the
stern deployment had not been tried by our group, and because the
A-frame provided only 6 inches of clearance on each side of the CTD, I
decided not to use the A-frame and had it removed from the ship.  The
starboard deployment using the crane is not optimum, and the long whip
between the crane and the CTD provides the opportunity of the CTD to
swing through a wide arc. Unfortunately, the CTD collided with the side
of the ship several times during HOT-32. Although I never observed
this, the rosette sustained damage from several impacts. Most of this
damage was apparently done on the Friday 0300 to 1500 watch. CTD
operations were cancelled at 1800 on this day. The CTD also hit the
ship on the final cast of the cruise (station 5), although the weather
was quite calm at this time. A better system for deploying the CTD from
the Wecoma needs to be developed for HOT-33.

      In addition to the CTD deployment situation, there were some
other equipment problems on HOT-32.  The top of the GOFS spar buoy was
lost on this cruise during transit from station 2 to 3.  Apparently,
the top section of the spar was not adequately tied down.  Both of the
WOCE surface water sampling buckets were also lost on this cruise.
Both of these were broken when they collided with the side of the ship
during water sampling.  The Wecoma's level wind also malfunctioned
several times.  This problem was discovered quickly and no damage was
done to the wire or our gear.  The CTD tarp was not set up on HOT-32.
We attached the tarp to the equipment van and left it on the deck in
case we needed to sample the rosette in the rain.  It would be nice to
get the tarp set up on HOT-32.  The happy hookers available from the
ship were completely inadequate during this cruise.  Frequently, only
one of these was operable, and only one tag could be attached to the
rosette at a time.  This often delayed the recovery of the CTD and
probably contributed to the rosette damage.

     Ancillary Programs

      Dave Keeling             CO2
      Paul Quay                delta 14C
      Marlin Atkinson          oxygen sensor
      Lisa Campbell            phytoplankton taxonomy
  
Student samples:

      Jim Christian