Hawaii Ocean Time-series (HOT)
in the School of Ocean and Earth Science and Technology at the University of Hawai'i at Manoa


HOT-34: Chief Scientist Report


Chief Scientist: F. BINGHAM


                        Cruise report for HOT-34
                              R/V Wecoma
                          February 12-17, 1992
                                          
                    Frederick Bingham, Chief Scientist
          
          
          
Scientific Crew:
          
     Stephen Barker
     Frederick Bingham
     Chris Carillo
     Jim Christian
     Ken Constantine
     Reka Domokos
     John Dore
     Dale Hebel
     Terry Houlihan
     Elaine Kotler
     Jean Pietraszek
     Marc Rosen
     Chuck Stump (representing Steve Emerson)
     Flo Thomas (representing Marlin Atkinson)
          
          
Itinerary (local time):
          
Wednesday, Feb. 12
     1015 Depart Snug Harbor
     1250 Arrive Kahe Point
          
Thursday, Feb. 13
     0250 Arrive Station ALOHA
     0500 Deploy sediment trap
     0700 Begin CTD operations
          
Friday, Feb. 14
     0600 Deploy Primary Productivity array
     1900 Recover Primary Productivity array
          
Saturday, Feb. 15
     0700 Finish CTD burst sampling
     0800 Commence two deep casts for Marlin Atkinson
          
Sunday, Feb. 16
     0000 Commence yo-yo cast
     0700 Recover sediment traps, begin transit to station 3
     1100 Arrive station 3
     1330 Finish station 3, begin transit to station 4
     2240 Arrive station 4

Monday, February 17
     0000 Finish station 4, begin transit to station 5
     0130 Arrive station 5
     0215 Finish station 5, begin transit to Snug Harbor
     0945 Arrive Snug Harbor


Cruise Brief:

     Ship loading was made much easier than previous HOT cruises by use
of a university van which has a larger capacity than the truck which is
normally used.

     Last minute problems with broken CTD connectors caused a slightly
late departure.  We departed Snug Harbor at 1015 and arrived Kahe Point
at 1250.  No problems were encountered at the Kahe Point station.

     Sediment traps were deployed successfully at the southeast edge of
station ALOHA.  However, a potentially dangerous situation developed as
the spar buoy was being released into the water in rolling seas.  It is
recommended for the future that tag lines be kept on the spar buoy as
it is being lowered into the water to prevent it from swinging
excessively.  Other than that, deck operations were generally safe,
smooth and successful.

     The primary productivity array was deployed and recovered on Feb.
14.  On recovery it was discovered that three incubation bottles were
lost along with the radioisotopes they contained.

     CTD operations commenced after arriving at the center of station
ALOHA.  At 1500 on 13 Feb., on the first 1000 meter cast at ALOHA, an
electronics problem was discovered immediately upon putting the CTD in
the water.  The CTD was brought back on deck.  Diagnosis and repair of
the problem continued until approximately 2300.  The problem was traced
to a bad conductor in the winch cable.  A spare conductor was used in
place of the bad one which seemed to solve the problem.

     At some point during the cruise, the CTD data from station 2 cast
1, the WOCE deep cast, were accidentally deleted from the computer.  We
were unable to subsequently recover the data from video tape.
Fortunately, CTD data to the bottom were collected on two later casts.

     Because of heavy rains on Thursday night and Friday, a tarp was
deployed over the rosette as it was being sampled.  However the tarp
did not function well.  Some cross-pieces which would have improved the
tarp's performance were missing.  In addition, the design was not
tested prior to the beginning of the cruise.  Some parts of the
assembly were not able to hold up under stress and broke soon after
deployment.

     Following the burst sampling, two deep casts were made for the
benefit of Marlin Atkinson who is testing the Morita Oxygen sensor.
Following these deep casts a yo-yo cast was made to sample intrusive
features in the intermediate water.  The CTD was lowered to 400 meters
and then raised and lowered 8 times between 400 and 700 meters.

     Casts to 1000 meters were made at stations 3 and 4 and a cast to
within 100 meters of the bottom was made at station 5.

     ADCP data was collected during the cruise.  However data
collection was not started until Feb. 13 at 0541.  Also, GPS navigation
was not recorded within the ADCP data stream.

     XBT's were deployed at regular intervals on the transit between
stations 3 and 4 and between stations 4 and 5.

     A number of technical problems with the WOCE equipment occurred
during the cruise.  None of these except the above- mentioned CTD
conductor problems had a major impact on the ability to gather data.


Ancillary Programs:

Dave Keeling		CO2
Marlin Atkinson		Morita Oxygen sensor
Steve Emerson  		Gas Ratios
Paul Quay      		delta C14
Lisa Cambell    	phytoplankton taxonomy


Student Samples:

Jim Christian
Sean Kennan (yo-yo)
John Dore