HOT-180: Chief Scientist Report
Cruise ID: KM 06-11
Departed: March 31, 2006 at 0900 (HST)
Returned: April 4, 2006 at 0800
Vessel: R/V Kilo Moana
Operator: University of Hawaii
Master of the Vessel: Captain Rick Myer
Chief Scientist: Thomas K. Gregory
OTG Technicians: Gabe Foreman and Steve Poulos

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. Five stations were to be occupied during the cruise, in the following order:
1) Station 1, referred to as Station Kahe, is located at 21 20.6'N, 158 16.4'W and was to be occupied on the first day of the cruise for about 2 hours.
2) Station 2: ALOHA (A Long Term Oligotrophic Habitat Assessment) is defined as a circle with a 6 nautical mile radius centered at 22 45'N, 158W. This is the main HOT Station and was to be occupied for 3 days.
3) Station 51, is the site of the MOSEAN Mooring, is located at 22º 45'N, 158º 6’W and was to be occupied on the 4th day of the cruise for about 30 minutes.
4) Station 50 is the site of the WHOTS Mooring, is located at 22o 46.1'N, 157o 53.4’W and was to be occupied on the 4th day of the cruise for about 30 minutes.
5) Station 6, referred to as Station Kaena, is located off Kaena Point at 21º 50.8'N, 158º 21.8'W and was to be occupied on the 4th day of the cruise 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, we were to perform CTD casts to collect water for the gas array and other experiments and assays following the deployment of the sediment trap array. Optics work was to be performed on the second day of the cruise. The 36 hour period was to begin on the second day of the cruise.
Three free-drifting arrays were to be deployed on this HOT cruise including the gas array, primary productivity array and sediment trap array.
Phytoplankton net tows were to be conducted by B. Watkins on several occasions throughout the cruise.
A Profiling Reflectance Radiometer (PRR) was to be deployed for half-hour periods near noon time on three days.
A package including a Wet Labs AC9, a Chelsea Fast Repetition Rate Fluorometer (FRRF), and a SeaBird Seacat was to be used to profile the upper 200 m at Sta. ALOHA on four separate occasions including one nighttime and three daytime casts.
After CTD work at Station ALOHA was accomplished, the ship was to transit to recover the floating sediment trap array. Following this operation, we were to perform CTD casts at both MOSEAN and WHOTS mooring and then transit to Station Kaena.
The following instruments were to collect data throughout the cruise:
shipboard ADCP, thermosalinograph, and two anemometers.

2. SCIENCE PERSONNEL
Bjorkman, Karin
UH/BEACH
Research Specialist
Curless, Susan
UH/BEACH
Research Associate
Defelice, Suzanne
UH/PO
Research Associate
Doggett, Ken
UH/BEACH
Research Associate
Foreman, Gabe
UH/OTG
Marine Technician
Fujieki, Lance
UH/BEACH
Research Associate
Gregory, Thomas
UH/BEACH
Chief Scientist
Harlan, Adriana
UH/BEACH
Research Associate
Huey, Teh Soo
UH/PO
Undergraduate Student
Lennon, Jay
Brown/BEACH
Postdoctoral Researcher
Lethaby, Paul
UH/PO
Research Associate
Martiny, Jennifer
Brown/BEACH
Assistant Professor
Menviel, Laurie
UH/PO
Graduate Student
Poulos, Steve
UH/OTG
Marine Technician
Sadler, Dan
UH/BEACH
Research Associate
Santiago - Mandujano, Fernando
UH/PO
Research Associate
Smith, Justin
UH/PO
Undergraduate Student
Taylor, Mana
UH/BEACH
Graduate Student
Tottori, Steve
UH/PO
Marine Technician
Watkins, Blake
UH/BEACH
Marine Engineer

3. GENERAL SUMMARY
Nearly all objectives for HOT 180 were successfully completed. We had trouble with the battery on the AC9 and so we cancelled the second optics on the last day. We also cancelled the MOSEAN mooring CTD cast to save time for work at Station Kaena.

4. R/V Kilo Moana, OFFICERS AND CREW, TECHNICAL SUPPORT
The R/V Kilo Moana maintained the excellent ship support for our work we have come to expect from other vessels in the UNOLS fleet. The officers, crew and OTG technicians were most helpful and accommodating. They showed enthusiasm and concern for our work and were very flexible in receiving changes in our operational schedule.

5. DAILY REPORT OF ACTIVITIES (HST)
March 30, 2006; Loading Day
Equipment loaded during this day.
March 31, 2006
The ship departed from Snug harbor at 0900. We began Station Kahe operations around noon and performed a weight cast, PRR cast and then a 1000 m CTD cast after which we steamed to Station ALOHA.
We arrived at Station ALOHA at 2230 and deployed the sediment trap array at 2353.
April 1, 2006
We performed two 200 m, five 1000 m and one full-depth CTD casts. The 36 hour period started at 1130.
The gas array was deployed at 0540
The ATE was deployed at 1300.
B. Watkins performed plankton net tows at 1024, 1322 and 2225.
April 2, 2005
Seven 1000 m CTD casts were conducted on this day.
The gas array was recovered at 0740.
The primary production array was deployed at 0555 and recovered at 1923.
The PRR was deployed at 1234.
AC9/FRRf casts were conducted at 1307.
B. Watkins performed plankton net tows at 0106, 1006 and 2225.
April 3, 2006
The second deep cast was initiated at 0010 and ended the 36 hour period. Three shallow casts were performed: one each at ALOHA, WHOTS and Kaena. The regular 2500 m cast was performed at Station Kaena at 2116.
The sediment trap array was recovered at 0708.
The PRR was deployed at 1310.
AC9/FRRf casts were conducted at 0348 and 1331.
April 4, 2006
Arrived at Snug Harbor at 0800 and completed a full offload.

Sub component programs:
Investigator: Project/Institution:
----------------- --------------------
Bob Bidigare HPLC pigments/UH
Mike Landry Zooplankton dynamics/UH
John Dore CO2 dynamics/UH
Ancillary programs:
Investigator: Project/Institution:
----------------- --------------------
Charles Keeling CO2 dynamics and intercalibration/SIO
Mark Abbott/Ricardo Letelier Optical measurements/OSU
Paul Quay DI13C and O isotopes/UW
Penny Chisholm Prochlorococcus population dynamics/MIT
Ancillary research during this cruise:
Investigator: Project/Institution:
----------------- --------------------
Jennifer Hughes-Martiny Spatial microbial dynamics/Brown University
Stuart Donachie/Mana Taylor Marine fungi/UH