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


HOT-81: Chief Scientist Report


Chief Scientist: D. HEBEL


                           HOT 81 Cruise Report
                              R/V Moana Wave
                            10-14 March, 1997


Personnel List

HOT 81:

WOCE group:
Jefrey Snyder*          	Mar. Electronic Tech.          		UH
Craig Nosse             	Research Associate              	UH
Matt Cochran			Student Assistant			UH
Don Wright			Student Assistant			UH
Ilse Hamann			Scientist				?

JGOFS group:
Dale Hebel              	Chief Scientist (co-PI JGOFS)  		UH
Christofer Winn                	Scientist (PI, JGOFS carbon component)	UH
Karin Bjorkman          	Scientist               		UH
Dan Sadler*             	Research Associate          		UH
Ursula Magaard			Research Associate          		UH
Stuart Donachie			Scientist				UH
Terrence Houlihan		Research Associate          		UH

Ancillary projects
Mai Lopez               	Scientist               		SIO
Stephanie Chirstensen		Graduate Student			UH
Chuck Stump			Scientist				UW

STAG
Sharon Stahl               	Electronic Technician       		UH-UM
Dave Gravatt             	Deck Technician              		UH-UMC

* Watch Leader



Itinerary (approximate local time):
-----------------------------------

Monday, 10 March.
    	0900    Departed Snug Harbor
    	1130    Arrived Kahe Pt. (Sta. 1)
	1140    Weight cast (1000m)
	1240    PRR-600 cast
	1310    s1c1 (aborted)
	1400    s1c2 (aborted)
	1440    s1c3 (aborted)
	1530    s1c4 (aborted)
    	1600    Departed Kahe
	2350    Arrived Aloha (Sta. 2)
	
Tuesday, 11 March
	0030    Plankton net tow
	0120    Began sediment trap deployment
    	0200    Completed sediment trap deployment (22 44.77N,157 59.67W)
	0240    Test cast to 50 m
	0410    Test cast to 50 m
    	0440    Arrived Aloha (center of circle), WOCE deep cast (s2c1)
    	0750    CTD on deck
    	0930    Began 36 hr "burst sampling" (s2c2)
    	1050    Plankton net tow
	1130    PRR-600 cast
    	1200    s2c3
	1300    Plankton net tow
    	1400    s2c4
    	1700    s2c5
    	2000    s2c6
    	2200    Plankton net tow
	2300    s2c7
Wednesday, 12 March
        0010    Plankton net tow
	0200    s2c8
       	0320    Go-Flo cast
	0510    s2c9
        0630    Deployed primary productivity array (22 44.4N, 157 59.2W)
     	0800    s2c10
	1100    s2c11
	1210    PRR-600 cast
	1230    Seacat cast
        1300    Plankton net tow
        1400    s2c12
        1700    s2c13
	1315    Plankton net tow
        1850    Retrieved primary productivity array (no position recorded on
		bridge log & wrong position on data sheet)
	2000	s2c14
	2230    OPC deployed
Thursday, 13 March
	0610    OPC recovered
	0620    Departed Sta. ALOHA
	0630    Go-Flo cast (5 m water for experiments)
	0840    Sediment trap recovery (22 52.6.3N, 157 59.5W)
        1110    s8c1 (1.5 nm downwind of mooring)
	1220    PRR-600 cast (cloudy)
	1300    s8c2 (300 m)
	1340    PRR-600 cast (sunny)
	1500    s8c3 (Wetlab fluorometer test)
	1610    Mooring position 22 26.87 N, 158 06.48 W
	1630    Departed station 8
	2220    Arrived Kahe Pt. (sta. 1)
 Friday, 14 March
	0030    Departed Kahe
       	0800    Arrived Snug Harbor
        1200    Completed offloading operations


Narrative:
----------

HOT 81 was conducted aboard the R/V Moana Wave 10-14 March 1997.
Captain Hayes was the master of the vessel and Dale Hebel chief
scientist.  There were a total of 17 participants in the scientific
party composed of 5 WOCE, 8 JGOFS, 2 ancillary and 2 STAG.  Three
stations were occupied during HOT 81 being Kahe Pt. (sta. 1), Station
ALOHA (sta. 2), and the surface mooring location (sta. 8).  All
scheduled operations were completed and all Core samples were collected
in spite of CTD problems which caused us to abort the regular CTD cast
on our initial occupation of Kahe.  The problem was a greater than
normal difference in the paired CTD temperature thermistors (4-6
millidegree C difference).  Various solutions were tried including
switching with the 2 extra sensors, pump tests, pump replacement, and
finally re-entering of the original calibration values in the
calibration file.  Since the temperature sensors were just calibrated
before the cruise, it appears that the calibrating facility either
provided erroneous calibration values or mixed up the paired sensor and
calibration values.  In any respect, troubleshooting the problem
consumed approximately 22 hrs causing us to abort the original CTD cast
at Kahe, although we were able to make up the time (and more) which
allowed us to reoccupy Kahe on the return leg.  This time the cast was
successful although only enough dissolved oxygen samples were collected
to calibrate the CTD oxygen sensor.  During the cruise all underway
measurement systems (thermosalinograph, ADCP, meterological
instruments, pCO2 and fluorometer) were operable and functioned
normally throughout the cruise.   Experiments on EOC and ectoenzymes
were performed as well as towing of the OPC within the ALOHA circle.

Daily Activities (HST)

4 March 1997
Precruise meeting MSB 305 at 1030 hrs.

7 March 1997
All equipment and supplies were loaded on the R/V Moana Wave,
assembled, and tested with the exception of the carbon equipment which
was setup on Saturday since Chris Winn who was out of town on loading
day.

10 March 1997
All science personnel were aboard by 0830 hrs and the ship departed on
schedule (0900 hrs.).  Once outside the mile buoy the fire and abandon
ship drill were conducted followed by the usual science meeting.  We
arrived Kahe on schedule and conducted a weight cast to 1000m followed
by a PRR-600 cast.  The problem with the CTD thermistors was recognized
during the first CTD cast and over the next 2 1/2 hrs various attempts
at solving the problem were initiated.  After the 4th aborted CTD cast
we decided to depart station and continue troubleshooting during our
transit to ALOHA.  We departed Kahe at 1600 hrs and arrived at ALOHA
about midnight.  Seas were generally favorable although there was a
moderated swell from the east due to the high winds (20-50 mph)
experienced most of the preceeding week.

11 March 1997
Once on station we conducted a plankton net tow followed by deployment
of the sediment traps.  At this point the CTD problem had not been
solved and additional tests ensued.  After finding a solution the WOCE
deep cast was initiated at approximately 0500 hrs.  This put us about 2
hrs behind our scheduled deployment.  This time was made-up over the
course of the day and by the next shift we were back on schedule.

12 March 1997
All operations functioned normally and on schedule.  Completed CTD
casts s2c8 -s2c14, 3 plankton net tows, 1 Go-Flo cast for trace metal
clean primary productivity samples,  1 PRR cast, deployment and
retrieval of primary productivity array, and initial deployment of
OPC.  The schedule has been revised since the sediment trap drift
allows reduced transit time and a day-time recovery of the sediment
traps as well as the added benefit of a light cast at station 8 to
calibrate the moored optical sensor.  Seas remain favorable for
scheduled operations.

13 March 1997
OPC operations continued until 0700 hrs within the ALOHA circle
followed by a surface Go-Flo cast (for experimental work samples),
sediment trap retrieval, and occupation of station 8.  At station 8 two
light casts (PRR) were conducted ( one under cloudy and one under sunny
conditions), as well as 3 CTD casts.  Two CTD casts were the previously
established 1000 and 300 m casts while the third was for calibration of
the OPC fluorometer.  We departed station 8 at 1630 hrs enroute to
Kahe.  We arrived Kahe at approximately 2230 hrs and conducted the CTD
cast missed on the initial occupation.  All samples were collected with
the exception of a complete dissolved oxygen profile due to the limited
time allowed between station and docking.  Dissolved oxygen samples
were taken at specified calibration depths.

14 March 1997
We departed Kahe station at 0030 hrs enroute Honolulu and Snug Harbor.
We arrived Snug Harbor 0800 hrs and completed offloading operations by
1200 hrs.


Weather
-------

HOT 81:
    The weather was mostly sunny with winds and seas typical of station
    ALOHA at this time of year.  Below is listed the cruise bridge log
descriptions and the various values represent the range for that day.
Under wind, sea, and swell there will be two designations, the first is
the direction (in degrees), the second for wind is in kts, sea in
Beauford force, and swell in feet, barometer in inches of Hg, temp  C
and clouds in tenths.

Day   Date  	Wind	       Sea          Swell    	  Barometer   Temp    Clouds

Mon   10 March  115-155,0*-19  115-155,1-3  070-150,2-4   29.83-29.93  73-77  6-10
Tues  11 March  120-180,5-10   120-180,2    090-150,4-6   29.75-29.85  71-72  3-8
Wed   12 March  155-180,10-20  155-180,2-3  100,5-6       29.74-29.78  70-75  3-7
Thur  13 March  0-200,0-21     0-200,1-4    conf-200,2-3  29.75-29.92  70-76  3-10
Fri** 14 March  130-145,10-12  130-145,2-3  120-150,2     29.91-29.92  74-75  3-4

*0=light or 0 entry
**Only two entries (0200 & 0600 hrs)


Equipment and methods:
----------------------
With the exception of the initial CTD problems and CWS pump all
standard equipment functioned properly.


Sub component programs:
-----------------------

Investigator:               		Project:
-------------              		--------

Christopher Winn (UH)       		DIC, pH, Alk., pCO2
Bob Bidigare (UH)           		HPLC pigments
Michael Landry (UH)     		Zooplankton dynamics

Ancillary programs:
-------------------

Investigator:               		Project:
-------------              		--------
Charles Keeling (SIO)       		CO2 dynamics and intercalibration
Paul Quay (UW)          		DIC and 13C

Students:
---------

Others:
-------
Mark Huntley/Mai Lopez      		Optical plankton counting
Stuart Donachie          		Ectoenzyme activities
Karin Bjorkman				EOC experiments