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Hawaii Ocean Time-series (HOT)
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HOT-129: Chief Scientist ReportChief Scientist: F. SANTIAGO-MANDUJANO
HOT-129 Chief Scientist's Cruise Report
R/V Ka'Imikai O Kanaloa
August 6-10, 2001
Departed: August 6, 2001 at 0900 (HST)
Returned: August 10, 2001 at 0700
Vessel: R/V Ka'Imikai O Kanaloa
Operator: University of Hawaii
Master of the Vessel: Captain Robert Hayes
Chief Scientist: Fernando Santiago-Mandujano
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:
1) Station 1, referred to as Station Kahe, is located at 21o 20.6'N,
158o 16.4'W and was to be occupied on August 6 for about 3 hours.
2) Station 2: ALOHA (A Long Term Oligotrophic Habitat Assessment) is
defined as a circle with a 6 nautical mile radius centered at 22o 45'N,
158oW. This is the main HOT station and was to be occupied for 3 days
from August 7 to August 9.
3) Station 8, referred to as HALE-ALOHA is the location of the deep
ocean mooring (22o 20.0'N, 158o 10.6'W). It was to be occupied on
August 9 for about 2 hours.
4) Station 6, referred to as Station Kaena , is located off Kaena Point
at 21o 50.8'N, 158o 21.8'W was to be occupied on August 9 for about
2 hours.
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.
Upon arrival at Station ALOHA, a net tow was to be conducted, followed
by the deployment of a free-drifting sediment trap array. After
deployment, a full-depth CTD cast was to be conducted, followed by CTD
casts 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 on August 8: an
oxygen balance experiment (O2) for 24 hours, and a primary production
experiment for 12 hours. A plankton net was to be deployed near noon
and midnight on August 7 and 8 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
1000-m 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.
A Profiling Reflectance Radiometer (PRR) was to be deployed for
half-hour periods near noon time on August 6, 7 and 8.
An In Situ pump for C. Benitez-Nelson's experiment was to be deployed
for 1.5 hr on August 7 and 8.
The following instruments were to collect data throughout the cruise: a
shipboard ADCP, a thermosalinograph and fluorometer, and an anemometer.
2. SCIENCE PERSONNEL
WOCE group:
Jeremiah Johnson (Watch Leader) Research Associate UH
Noel Larson Research Associate UH
Rebekah Moore Volunteer UCD
Lal Ratnapala Research Assistant UH
Fernando Santiago-Mandujano Chief Scientist (Res. Assoc.) UH
Mark Valenciano Electronics Technician UH
JGOFS group:
Colleen Allen Research Associate UH
Jennifer Brum Graduate Student UH
John Dore Scientist UH
Lance Fujieki (Watch Leader) Computer Specialist UH
Anne Gasc Research Associate UH
Dale Hebel Scientist UH
Paul Morris Technician UH
Ancillary projects:
Tom Gregory Technician (C. Benitez-Nelson, UH)
Andrew Hansen Technician (J. Zehr, UCSC;
J. Montoya, Georgia Inst. Technol.)
3. GENERAL SUMMARY
All scientific objectives were met. Fourteen 1000-m CTD casts and one
deep cast were obtained at station ALOHA. One 1000-m CTD cast was
obtained at station Kahe and two at HALE-ALOHA. One near-bottom cast
(~2500 m) and one 300 cast were obtained at station 6. Two shallow
casts (< 600 m) were conducted at stations Kahe and ALOHA to
troubleshoot problems encountered with the CTD.
The array of floating sediment traps, the primary productivity array,
and P. Morris' O2 array were deployed and recovered without incidents.
The sediment traps array drifted 10 nm southwest from Station ALOHA.
C. Allen and T. Gregory completed successfully 6 pairs of plankton net
tows.
The In situ pump was successfully deployed as planned, as well as the PRR.
The ship's port generator had problems during transit to stations Kahe and
ALOHA. This delayed the arrival to station ALOHA until 0200 (August 7).
Winds were easterlies at 20 kt, and 5-6 ft seas.
The ADCP ran without interruption throughout the cruise, as well as the
thermosalinograph, fluorometer, and the ship's anemometer.
We arrived back at Snug Harbor on August 10 at 0700. Complete off-load
took place immediately.
4. R/V KA'IMIKAI O KANALOA, OFFICERS AND CREW, TECHNICAL SUPPORT
The R/V Ka'Imikai O Kanaloa continues to maintain the excellent ship
support for our work. The officers and crew were most helpful and
accommodating. They showed enthusiasm and concern for our work and
were very flexible in receiving changes in our operational schedule.
Technical support during this cruise was excellent. STAG personnel were
available at any time to assist in our work and made things much easier
for us.
5. DAILY REPORT OF ACTIVITIES (HST)
August 3, 2001; Loading Day
Equipment loaded on this day. Reterminated CTD wire and tested CTD system.
August 6, 2001
The ship departed from Snug harbor at 0900. Fire and abandon ship drills
conducted at 0930, followed by a short science meeting during which the
cruise schedule was reviewed, and safety issues were addressed.
Arrived to Kahe station at 1130, and a weight cast (400 lb) to 1000 m
was conducted during which M. Valenciano inspected the CTD wire. At
1300 the Profiling Reflectance Radiometer (PRR) was deployed.
Troubleshooting of the ship's port generator took place before the
CTD cast.
A CTD cast was conducted at 1400 but was aborted at 580 dbar due to
glitches in the data. The cast was repeated and the ship headed towards
station ALOHA.
Winds were 15 kt easterlies and 3 ft seas.
August 7, 2001
Arrived at station ALOHA at 0200 due to problems with the ship's
generator. Proceeded to deploy the sediment traps. The deep WOCE cast
started at 0300 but was aborted at 170 m due to data glitches. After
troubleshooting the CTD, it was decided to re-schedule the deep cast
after the end of the 36-hr CTD period. The 36-hr CTD cast period
started at 0900. A total of six 1000-m CTD casts were conducted this day.
Two pairs of net tows were conducted during the day and another pair at
night.
The PRR was deployed at 1230 and the In situ pump was deployed at 1500
Winds were 20 kt easterlies and 6 ft seas.
August 8, 2001
Seven 1000-m CTD casts were conducted during this day, ending the 36-hr
CTD cast period at 2100. The WOCE deep cast was started at 2300.
The O2 array was deployed at 0400. The primary productivity array was
deployed at 0600 and was retrieved at 1900.
One pair of net tows was conducted in the day and two pairs at night.
The PRR was deployed at 1230, and the In situ pump was deployed at 1500.
Winds were easterlies 20 kt, 6 ft seas.
August 9, 2001
The deep CTD cast that started at 2300 on August 8 was completed by 0300.
The O2 array was recovered at 0530.
The sediment trap array was recovered at 0700. The array drifted 10 nm
southwest from Station ALOHA.
A 1000-m CTD cast was conducted at the HALE-ALOHA station at 1000,
and a second 1000-m cast was conducted at 1300 to test some of
the CTD equipment.
A near-bottom CTD cast (~2500 m) was conducted at 1900 at station 6. A
300-m CTD cast was conducted afterwards to test STAG's new SeaPoint
fluorometer. Operations ended at 2130.
Winds were easterlies 18 kt, 5 ft seas.
August 10, 2001
Arrived at Snug Harbor at 0700. Complete off-load took place immediately.
Sub component programs:
Investigator: Project:
----------------- ----------
Bob Bidigare HPLC pigments/UH
Michael Landry zooplankton dynamics/UH
Ancillary programs:
Investigator: Project:
----------------- ----------
Charles Keeling CO2 dynamics and intercalibration/SIO
Paul Quay DIC and 13C/UW
Abbott/Letelier optical measurements/OSU
Claudia Benitez-Nelson phosphorus isotopes, Th234/UH
Peter J. LeB. Williams oxygen balance/U Wales Bangor
Jon Zehr Nif genes, N2 Fixation/UCSC
Joe Montoya 15N/N2 Fixation/Georgia Inst. Technol.
Others:
Hebel, Dore, Karl EOC/UH
John Dore P15N/UH
Jennifer Brum dissolved DNA, viruses/UH
Paul Morris oxygen balance/UH
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