HOT-126: Chief Scientist Report

Chief Scientist: M. ERICKSON

          HOT-126 Chief Scientist's Cruise Report
                 R/V Ka'Imikai O Kanaloa
                     May 14-18, 2001

Departed:  May 14, 2001 at 0900 (HST)
Returned:  May 18, 2001 at 0700
Vessel:  R/V Ka'Imikai O Kanaloa
Operator:  University of Hawaii
Master of Vessel:  Captain Robert Hayes
Chief Scientist:  Matthew J. Erickson
STAG Electronics Technician:  Steve Poulos
STAG Deck Operations:  David Gravatt


1.  SCIENTIFIC OBJECTIVES

  The objective of this cruise was to maintain a collection of
hydrographic and biogeochemical  data at the Hawaii Ocean Time-series
(HOT) stations.  Four Stations were to be occupied during the cruise,
in the following order:

Station 1:  Station Kahe is located at 21 20.6' N, 158 16.4'W and was
to be occupied on May 14 for 3 hours.

Station 2:  Station ALOHA (A Long-term Oligotrophic Habitat Assessment)
is defined as a circle with a 6 nautical mile radius centered at 22 45'
N, 158 W.  This is the main HOT station and was to be occupied for 3
days from May 15 to May 17.

Station 8:  Station HALE ALOHA was the location of the deep ocan
mooring 22 20.0' N, 158 10.6'W.  It was to be occupied on May 17 for
about 2 hours.

Station 6:  Station Kaena, is located of Kaena Point at 21 50.8' N,
158 21.8'W was to be occupied on May 17 for about 2 hours.


   Upon arrival at Station 1 a weight test was conducted.  After the
weight cast was determined successful a PRR light cast was
conducted.  A single CTD cast was to be conducted at Station 1 to
collect continuous profiles of various physical and chemical
parameters.  Water samples were to be collected at discrete depths for
biogeochemical measurements.

   At Station ALOHA a free-drifting sediment trap was deployed.  After
deployment, a full- depth CTD cast was to be conducted.  Following
this cast CTD casts were to be conducted at strict 3 hour intervals for
at least 36 hours for continuous and discrete data collection, followed
by another full-depth CTD cast.  Two other free-drifting arrays were to
be deployed.  One array was to be deployed for 12 hours for a primary
production experiment on May 16, and the other was to be deployed for
24 hours for an O2 flux experiment on May 16.  Light measurements were
taken using a PRR near 12:30.  A plankton net was to be deployed near
12:00 and 00:00 on May 15 and 16.  An in situ pump experiment was to be
conducted at 13:00 on Mat 15 and 16 at Station ALOHA.

   After work at Station ALOHA was accomplished, the ship was to transit
to recover the sediment trap array.  After the sediment traps were
recovered, the ship was to transit to Station 8, to conduct one CTD
cast, after which the ship was to transit to station 6.

   A near-bottom CTD cast (~2500 m) was to be conducted at Station 6
including salinity samples for calibration, after which the ship was
to transit back to Snug Harbor.

   The following instruments were to collect data throughout the
cruise:  a shipboard ADCP, at thermosalinograph and fluorometer, and
an anemometer.


2.  SCIENCE PERSONNEL

JGOFS group:
  Karin Bjorkman                      Research Associate        UH
  Ann Gasc                            Research Associate        UH
  Lance Fujieki                       Research Associate        UH
  Matthew Erickson (Chief Scientist)  Research Associate        UH
  Dale Hebel (Watch leader)           Scientist (CO-PI)         UH
  Paul Morris                         Technician                UH

WOCE group:
  Fernando Santiago-Mandujano         Research Associate        UH
  Jeremiah Johnson (Watch leader)     Research Associate        UH
  Mark Valenciano                     Electronics Technician    UH
  Noel Larson                         Research Associate        UH
  Lal Ratnapala                       Research Assistant        UH
  T. Miyama                           Scientist                 IPRC

Ancillary projects:
  Tom Gregory                         Research Associate        UH
  Roberta Hamme                       Scientist                 UW
  Colleen Allen                       Research Associate        UH
  Peter Williams                      Scientist                 Bangor


  
3.  GENERAL SUMMARY

   Operations were conducted as planned with minor interruptions.
Thirteen 1000 m CTD casts, and two 4800 m casts were obtained at
Station ALOHA.  One 1000 m CTD cast was obtained at each of stations
Kahe and HALE-ALOHA.  One near-bottom cast (~2500 m) was obtained at
Station 6.  The CTD had numerous problems throughout the 36 hour
period.  Troubleshooting and repairing allowed for all casts to be
completed except for cast 3 at Station ALOHA.

   The primary productivity array was deployed and retrieved as planned
on May 16.  The array of floating sediment traps was deployed and
recovered with out incidents.  The O2 Flux array was successfully
deployed on May 16 and recovered on May 17.  C. Allen and T. Gregory
successfully completed 8 plankton net tows.

   Weather conditions were favorable throughout the cruise, with light
winds and flat seas.

   The ADCP ran without interruption throughout the cruise, as well as
the fluorometer, thermosalinograph and anemometer.

   We arrived back at Snug Harbor on May 18 at 0700.  A full off-load
of samples, material and vans took place immediately.


4.  R/V KA'IMIKAI O KANALOA, OFFICERS AND CREW, TECHNICAL SUPPORT

   The R/V Ka'Imikai o Kanaloa continues to provide excellent ship support
for the projects and ancillary investigators work.  The officers and
crew were most helpful and accommodating.  They were both concerned and
enthusiastic about the work and were very flexible in changes that
occurred in our operational schedule.

   Technical support during this cruise was excellent.  STAG personnel
made sure that they were available at any time to assist in our work
and made things much smoother during the cruise and back deck
operations.


5.  DAILY REPORT OF ACTIVITIES (HST)

May 11, 2001

  Equipment loaded on this day. 

May 14, 2001

  The ship departed from Snug Harbor at 0900.  Fire and abandon ship
drills were conducted at 0930, followed by a short science meeting
during which the cruise schedule was reviewed, new operations were
discussed, and safety issues were addressed.

  Arrived at Kahe Station at 1130 and a weight cast (400lbs) to 1000 m
was conducted during which M. Valenciano inspected the CTD wire.  At
1115 aerosol measurements were taken.  At 1300 the Profiling
Reflectance Radiometer (PRR) was deployed.  The CTD cast was conducted
at 1330, after which the ship began transit to  station ALOHA.

  Winds were light with flat seas.

May 15, 2001

  We arrived at station ALOHA at 0000 and proceeded to conduct a net
tow.  After the net tows were determined to be a success the sediment
traps were then deployed.  The deep WOCE cast started at 0300.  The
shallow WOCE cast began at 0800, which started the 36- hour CTD cast
period.  The CTD experience difficulties the next cast and water was
not able to be collected.  To make sure that all core samples were
taken scheduled sampling was shifted to solve the problem.  The CTD
again experienced difficulties during the JGOFS 2 cast and the cast was
aborted.  The JGOFS 2 cast was switched to a different cast and all
other scheduled sampling were shifted again.  A total of 5 1000 m CTD
casts were conducted this day.

  Two net tows were conducted at noon and two at night.  The PRR was
deployed at 1230 and aerosol measurements were conducted at 1115.  An
in situ pump was deployed at 1500.

  Light winds and flat seas.

May 16, 2001

  Seven 1000 m CTD casts were conducted during this day, and a second
deep cast was started at 2300.   Errors were detected throughout the
day in the CTD data, but troubleshooting revealed no distinct reason
for the errors.  M. Valenciano looked over the CTD and could not find
reasons for the errors, but corrected the problem and casts continued.

  The O2 Flux array was deployed at 0330 with no difficulty.  The
primary productivity array was deployed a 0600 and recovered at
1800.

  One net tows was conducted at 0100 and another at 1000.  The PRR was
deployed at 1230 and aerosol measurements were conducted at 1115.  An
in situ pump was deployed at 1500.

  Light winds and flat seas.

May 17, 2001

  The second deep CTD cast that started a 2300 on 5/16 was completed by
0300.  The O2 Flux array was recovered at 0600, after which we headed
to recover the sediment traps.  The sediment trap recovery was
completed by 0830.  The ship the proceeded to transit to Station HALE
ALOHA.  Aerosol measurements were taken at 1115.

  A 1000 m CTD cast was conducted at the HALE ALOHA station at 1400.

  A near bottom cast (~2500 m) was conducted at 1800 at station 6.

May 18, 2001

  Arrived at Snug Harbor at 0700.  A full offload of samples and JGOFS
vans took place immediately.


6.  SUB COMPONENT PROGRAMS AND SPECIAL PROJECTS
 
B. Bidigare            (UH)       HPLC pigments
M. Landry              (UH)       Zooplankton community structure


7.  SAMPLES TAKEN FOR OTHER INVESTIGATORS

C. Keeling             (SIO)      CO2 dynamics and intercalibration
P. Quay                (UW)       DIC and 13C
J. Porter              (UH)       Aerosol and ozone measurements
M. Abbot, R. Letelier  (OSU)      Spectral measurements