HOT-98: Chief Scientist Report

Chief Scientist: F. SANTIAGO-MANDUJANO

            HOT-98 Chief Scientist's Cruise Report
                     R/V Moana Wave
                   17-21 October 1998

Departed:  October 17, 1998 at 1000 (HST)
Returned:  October 21, 1998 at 0030
Vessel:  R/V Moana Wave
Operator:  University of Hawaii
Master of the Vessel: Captain John Stahl
Chief Scientist: Fernando Santiago-Mandujano
STAG Electronics Technician: Wilhelm Hervig
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. Three 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 October 17 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 October 17 to October 20.

3) Station 8, is the location of the HALE-ALOHA buoy (22o 27.5'N, 
158o 7.9'W). It was to be occupied on October 20 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 free-drifting sediment trap array was
to be deployed for 72 hours to measure sedimentation rates of
particulate matter. After deployment, CTD casts at strict 3 hour
intervals were to be conducted continuously for at least 36 hours for
continuous and discrete data collection. The ship was to be requested
to remain on station during this sampling period. Another free-drifting
array was to be deployed for 12 hours for a primary production
experiment on October 19. A plankton net was to be deployed near noon and
midnight on October 18 and October 19 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 on October 20, after which the ship was to transit back to Snug
Harbor.

The following instruments were to collect data throughout the cruise: a
shipboard ADCP, a thermosalinograph, a pCO2 system, a fluorometer, the
Licor light logger, and an array of meteorological instruments.


2.  	SCIENCE PERSONNEL

WOCE group:
 Fernando Santiago-Mandujano	 Chief Scientist (Res. Assoc.)	UH
 Craig Nosse    (Watch Leader)   Research Associate       	UH
 Mark Valenciano                 Electronics Technician     	UH
 Don Wright                      Research Associate           	UH

JGOFS group:
 Dale Hebel      (Watch Leader)  Ass't Specialist (co-PI JGOFS) UH
 Karin Bjorkman                  Research Associate             UH
 Terrence Houlihan 		 Research Associate		UH 
 Markus Karner			 Post-Doc	          	UH
 Louie Tupas                     Scientist (co-PI JGOFS) 	UH
 Lance Fujieki                   Computer Specialist          	UH
 Daniel Sadler                   Research Associate         	UH

Ancillary projects:
 Scott Nunnery                   Research Associate    UH - M. Landry
 Albert Calbet 			 Post-Doc	       UH/Zooplankton
 Nathaniel Ostrom	         Scientist             Michigan State University
 Jim Falter 			 Graduate Student      UH

3.  GENERAL SUMMARY

 All the primary JGOFS and WOCE objectives were accomplished and all
samples for ancillary projects were taken. 

 The 36-hour CTD burst sampling was completed and fourteen 1000-m casts
were obtained at station ALOHA in addition to two deep cast. Also one
1000-m CTD cast was obtained at each of the stations Kahe and
HALE-ALOHA. 

 One 8-bottle go-flo cast was successfully obtained at station ALOHA,
and the primary productivity array was deployed and recovered without
problems. The array of floating sediment traps was also deployed and
recovered without incidents; the sediment traps had drifted about 34 nm
south-west upon recovery. S. Nunnery and A. Calbet completed
successfully 6 plankton net tows.

 Weather conditions during the cruise were favorable to conduct all
 deck operations without problems. There were 10-20 kt easterlies and
3-5 ft waves.

 The ADCP ran without interruption throughout the cruise, as well as the
thermosalinograph, the pCO2 system, the Licor light logger, the
fluorometer, and the meteorological sensors.

 The signal from the Inverted Echo Sounder (IES) located at the center
of the ALOHA station was detected on the 12 kHz PDR.

 We arrived back at Snug Harbor on October 21 at 0030. Off-loading of
all deck and lab equipment was completed by noon, as there was another 
cruise scheduled to set sail after this cruise.


4.  R/V MOANA WAVE, OFFICERS AND CREW, TECHNICAL SUPPORT

 The R/V Moana Wave 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)

October 16, 1998; Loading Day

 Most of the deck equipment such as vans and winches had not been 
off-loaded from the previous HOT-97 cruise because there were no
other cruises before this one. Only minor equipment and materials
needed to be loaded by the JGOFS group and ancillary investigators. 
The WOCE group conducted a full equipment load. M. Valenciano
inspected the CTD cable termination and decided that it was not
necessary to do a retermination.

October 17, 1998

 Ship departed from Snug harbor at 1000. Fire and abandon ship drills
conducted at 1030, followed by a short science meeting during which the
cruise schedule was reviewed, and safety issues were addressed.

 Arrived to Kahe station at 1300 and started Profiling Reflectance
Radiometer (PRR) and Tethered Spectral Radiometric Buoy (TSRB)
deployments.

 A weight cast (400 lb) to 1000 m was conducted at 1340, during which 
M. Valenciano inspected the CTD wire. A 1000-m CTD cast followed at 1500.

 Departed to station ALOHA at 1700.

 Winds from the east of 20 kt, with 3-5 feet waves. Sea state 3.

October 18, 1998.

 Arrived at station ALOHA at 0120.
 
 A net tow was done at 0138, followed by the deployment of the floating
sediment traps. Transited back to station ALOHA at 0215 to begin the
CTD deep cast.

The IES was detected on the 12 Khz PDR at 0300.

 The near-bottom CTD cast was conducted without any problem, followed
by the shallow WOCE cast. This cast began the 36-hour period of CTD
casts at 3-hour intervals.  A total of six 1000-m casts were completed
this day at the ALOHA station.

 The PRR and TSRB were deployed at 1315.

 Three more net tows were successfully completed at 1015, 1330, and
2200.

 20 kt winds from the east decreasing to 10 kt in the last 12 hours of
the day, 4 feet waves, sea state 3.

October 19, 1998

 The 36-hour period of CTD casts at ALOHA ended at 2200.  A total of
thirteen shallow (1000-m) and one near-bottom cast had been conducted at
this station.

 A go-flo cast was obtained at 0200. The primary productivity array was
deployed at 0530, and retrieved at 1800.

 The PRR and TSRB were deployed at 1315.

 A net tow was obtained at 0100 and another one at 1330.

 Sediment trap satellite positions were received by e-mail, indicating
that the traps have drifted southwest outside of the circle.

 10 kt winds from the east, 3 feet waves, sea state 3.

October 20, 1998

 A second near-bottom cast at ALOHA was conducted at 0200, after the
ship returned from pumping tanks outside the circle.

 The PRR and TSRB were deployed at 1400.

 The array of sediment traps was successfully retrieved at 1100. 
The traps had drifted about 34 mn southwest of station ALOHA.

 Cruise operations ended with a 1000-m CTD cast at the HALE-ALOHA
station at 1430, after which the ship headed back to Oahu at 1600.

 10 kt winds from the east, 3 feet waves, sea state 3.

October 21, 1998

 We arrived at Snug Harbor at 0030. All the deck and lab equipment was
offloaded and labs were cleaned by noon.


SUB COMPONENT PROGRAMS AND SPECIAL PROJECTS

B. Bidigare (UH)                    HPLC pigments
M. Landry (UH)                      Zooplankton community structure
A. Calbet (UH)                      Zooplankton dynamics
N. Ostrom (Michigan State)          Nitrous oxide production
J. Falter (UH)                      Nitrous oxide production
K. Bjorkman (UH)                    Phosphorus dynamics
M. Karner (UH)                      Bacterial fluorescence probes
D. Hebel (UH)                       Organic matter exudates
L. Tupas  (UH)                      Primary production intercomparison


SAMPLES TAKEN FOR OTHER INVESTIGATORS

C. Keeling (SIO)                    CO2 dynamics and intercalibration
P. Quay (UW)                        DIC and 13C
E. Boyle (MIT)                      Trace metals
E. Laws (UH)                        Surface seawater
A. Malahoff (UH)                    Surface seawater
J. Porter (UH)                      Aerosol and Ozone measurements
B. Popp (UH)                        Nitrous oxide
M. Abbot (OSU)                      Spectral measurements