#ACCESSION NUMBER:
0103907

#CONTRIBUTOR:
Fernando Santiago-Mandujano
Data Manager
Physical Oceanographic Component of the
Hawaii Ocean Time-series (HOT) Program

#CONTRIBUTOR INSTITUTION:
University of Hawaii
Dept. of Oceanography
1000 Pope Road
Honolulu, HI 96822
(808) 956-7000
Email: santiago@soest.hawaii.edu

#ORIGINATOR:
Dr. Roger Lukas

#ORIGINATOR INSTITUTION:
University of Hawaii
Dept. of Oceanography
1000 Pope Road
Honolulu, HI 96822
(808) 956-7896 (phone)
(808) 956-9222 (fax)
rlukas@hawaii.edu

#TITLE: 
Thermosalinograph  Data of the Hawaii Ocean Time-series (HOT) program 
in the North Pacific 100 Miles North of Oahu, Hawaii for Cruises 
HOT228-238 during 2011

#PROJECT: 
Hawaii Ocean Time-series (HOT) Program

In 1987, the National Science Foundation established a special-focus research
initiative termed 'The Global Geosciences Program'. This program is intended
to support studies of the earth as the system of interrelated physical,
chemical, and biological processes that act together to regulate the
habitability of our planet. Two of the components of the Global Geosciences
Program are the World Ocean Circulation Experiment (WOCE) and the Joint Global
Ocean Flux Study (JGOFS) programs. The former is focused on physical
oceanographic processes and the latter on biogeochemical processes.

HOT was initially funded in 1988 as a 5-year program under WOCE and
JGOFS to make repeated observations of the physics, biology and
chemistry of the water column at a site north of Hawaii. A second 5-years of
funding were approved in 1994, 3 years more in 1998, and 3 years more in 2001.
In 2003 HOT was renewed for 5 more years, and in 2008 it was extended until
2010, and again in 2009 it was extended until 2013 (this last extension was
funded by the American Recovery and Reinvestment Act). HOT is part of the
ALOHA Observatory, which is being developed at HOT's station ALOHA.
Measurements at the HOT site contribute to the global description of heat,
fresh water and chemical fluxes at a site representative of the oligotrophic
North Pacific Ocean. The PO component contributes to the objectives of the
World Climate Research Programme (WCRP) Climate Variability and Predictability
(CLIVAR) Programme by providing information on interannual to decadal
variability of the North Pacific Ocean.

#ABSTRACT:
The HOT program makes repeated observations of the physics, biology and 
chemistry at a site approximately 100 km north of Oahu, Hawaii. Two stations 
are visited about once a month: Kahe Point (Station 1:  21.34N, 158.27W) and 
Station ALOHA (Station 2: 22.75N, 158W).  Various other stations are made
intermittently in support of similar research objectives or mooring 
deployments.  

HOT thermosalinograph data are recorded every 10 seconds from water 
collected by a continuous seawater system aboard each vessel from a 
depth of about 3 meters.  

This NODC Accession contains thermosalinograph data for HOT cruises 228-238
during 2011.  CTD and Niskin bottle data from the same cruises
are available in separate Accessions.

#PURPOSE: 
The objective of the physical component of HOT is to describe and understand 
the ocean climate and variability at a deep-water site in the North Pacific 
subtropical gyre near Hawaii. This requires a long time series of physical 
oceanographic variables, including water mass properties and currents, 
supporting and complementing the objectives of the biogeochemical component 
of HOT.

#LOCATION EXTREMES:
SOUTHERNMOST LATITUDE:  21.2409
SOUTHERNMOST LATITUDE HEMISPHERE: N
NORTHERNMOST LATITUDE:  23.0311
NORTHERNMOST LATITUDE HEMISPHERE: N
WESTERNMOST LONGITUDE: 158.3754
WESTERNMOST LONGITUDE HEMISPHERE: W 
EASTERNMOST LONGITUDE: 157.8618
EASTERNMOST LONGITUDE HEMISPHERE: W  

#LOCATION KEYWORDS: 
Hawaii, North Pacific Ocean

#SAMPLING STATIONS:
Continuous sampling by thermosalinograph from port to station and
back to port.  Navigation data are given for each salinity/temperature
pair.

For comparative purposes, the following hydrocast station
information is provided.

  Station     Coordinates   Approximate              Comments
                              Depth (m)

 1 (Kahe)    21 20.6'N, 158     1,500    HOT Program coastal station
             16.4'W

 2 (ALOHA)   22 45.0'N, 158     4,800    HOT Program open ocean station
             00.0'W

 3           23 25.0'N, 158     4,800    Established and ended in 1993
             00.0'W

 4           21 57.8'N, 158     4,000    Established and ended in 1993
             00.0'W

 5           21 46.6'N, 158      450     Established and ended in 1993
             00.0'W
 6 Kaena     21.85N,158.36W     2,500    Not taken on every cruise
   Point
 7 (Kauai    22 30.8'N, 158
 Basin)      10.0'W             4,800     Established in 1996
 8 (HALE     22 27.5'N, 158
 ALOHA)      7.9'W              4,800     Established in 1997

Casts have been obtained at station HALE-ALOHA during cruises
conducted for retrieval and/or re-deployment of the bottom-moored buoy.

#BEGIN AND END DATES: 
08 Jan 2011 - 22 Dec 2011

#SAMPLING PERIODS:
Year    Crs#         Start & End Dates       Ship            Chief Scientist
  ------------------------------------------------------------------------
23      228           8 Jan - 10 Jan 11      R/V Kilo-Moana       Nosse
        229          27 Jan - 30 Jan 11      R/V Kilo-Moana       Nosse
        230          27 Feb -  3 Mar 11      R/V Kilo-Moana       Curless
        231          10 Apr - 14 Apr 11      R/V Kilo-Moana       Nosse
        232           8 May - 12 May 11      R/V K-O-K            Curless
        233          18 Jul - 22 Jul 11      R/V Kilo-Moana       Curless
        234          29 Aug -  1 Sep 11      R/V Kilo-Moana       Curless
        235          25 Sep - 28 Sep 11      R/V Kilo-Moana       Nosse
        236           3 Nov -  7 Nov 11      R/V K-O-K            Curless
        237          27 Nov -  1 Dec 11      R/V K-O-K            Curless
        238          18 Dec - 22 Dec 11      R/V Kilo-Moana       Nosse

#PARAMETERS: 
Temperature (ITC-90)
Salinity (PSS-78)

#METHODOLOGY:
Generalities are given below.  Please see REFERENCES for additional
information. 

Each of the (approximately monthly) HOT cruises follows the same basic
pattern with some flexibility for ancillary projects to be done after the
core sampling has been completed. During transit from Honolulu to the
time-series station ALOHA (A Long-term Oligotrophic Habitat Assessment) one
weight test is done to between 700 and 1000 m at station 1 off Kahe Point
(16 km offshore from the western tip of Oahu, 21 20.6' N, 158 16.4' W,
1500 m water depth). Following the successful winch test, a CTD/rosette cast
to 1000 m is conducted. This cast serves as a "shakedown" for the remainder
of the cruise, and the functioning of the components of the CTD/rosette
system as well as coordination between winch, deck and console operators can
be tested. The training of new personnel in activities such as taking
meteorological observations, and sampling salinities is also done in this
station. The data taken at Kahe Point (station 1) represent an additional
time-series of water properties at a near-shore site.
 
Upon arrival at ALOHA (station 2), operations commence with a deep cast
(maximum depth approximately 4750 m), 36-hour burst sampling3 of the upper
1000 m at the same location, plus CTD casts to support ancillary JGOFS work
of about an extra 12 hours duration. Time permitting, the last CTD cast of
the cruise will be a deep cast. On occasion, one cast will be done at
station 3 (40 miles north of ALOHA at 23 25' N, 158 W).

The second and following casts at station ALOHA are sampled to at least 1000
m depth. Cast 2 is called a "density cast" because water samples are taken
at a number of specified density values ranging from [sigma-theta]= 27.37 to
the surface with the intent to resolve the profiles of salinity, dissolved
oxygen, and nutrients in potential density coordinates Depths sampled during 
the following casts within the 36-hour burst sampling period are chosen both 
by the JGOFS group and the WOCE team, who have to ensure that at least one 
water sample each is taken within the mixed layer, the shallow salinity 
maximum, the intermediate salinity minimum and the deepest position of 
the rosette for calibration of the CTD conductivity sensor. If oxygen 
bottles will be taken from the cast, then the sampling should include 
at least the mixed layer, oxygen maximum, oxygen minimum and the deepest 
rosette position for calibration of the CTD oxygen sensor. The second 
deep cast of the cruise (if there is one) should include sampling of 
oxygen bottles in at least seven levels appropriate for calibration of 
the CTD oxygen sensor, i.e. in the oxycline and two more levels below 
the oxygen minimum, in addition to the four levels mentioned before.

The primary objective of the HOT program is to assess variability in the
central Pacific Ocean on annual and interannual time scales. One of our most
important concerns, therefore, is to ensure that the highest possible
precision and accuracy is consistently maintained for all water column
chemical measurements. In order to achieve the highest possible data
quality, we have instituted a quality-assurance/quality-control program,
and have attempted to collect all ancillary information necessary to
ensure that our data are not biased by sampling artifacts.

Because sampling is over 36 hours, one can average out the effects
short-term changes of the depth of density surfaces and the magnitude of
hydrographic and nutrient variables (inertial, tidal, and shorter periods).

Thermosalinograph data are recorded every 10 seconds from water collected 
by a continuous seawater system aboard the vessel from a depth of 
about 3 meters.  These data are processed and quality controlled. Details 
of the thermosalinograph processing are documented (Tupas et. al., 1996).
 
Navigation data are also included in the thermosalinograph data file.
The navigation data are recorded every minute from the Global
Positioning System (GPS) aboard the vessel and linearly interpolated
at the same times of the thermosalinograph record.  These data include
latitude and longitude.
 
Error flags were incorporated in the data. 

#INSTRUMENT TYPES:

SBE-21 Seacat thermosalinograph system

#REFERENCES
1990 Chiswell, S., E. Firing, D. Karl, R.  Lukas and C. Winn. Hawaii
   Ocean Time-series Program Data Report 1, 1988-1989. SOEST Tech. Rept.
   1, School of Ocean and Earth Science and Technology, Univ. of Hawaii,
   Honolulu, HI, 269 pp.

Fujieki, L.A., F. Santiago-Mandujano, C. Fumar,
   R.  Lukas, and M. Church. Hawaii Ocean Time-series Data
   Report 21: 2009.  School of Ocean and Earth Science and Technology,
   Univ. of Hawaii, Honolulu, HI, November 2012. 648 pp.

#SUBMITTING MEDIUM:
FTP

#FILE FORMATS: 
Directories and files:
/data             root data directory
/0-data           Files as received by NODC from the originator

Filenaming convention:

hotcccts.dat      where ccc is cruise number, hot and ts.dat are constant

Data File Format:

Thermosalinograph data are distributed in a format specified here.

The thermosalinograph data for each cruise are stored together with the
navigation data in an ASCII file. The file names are determined by cruise name
and number. For example, the thermosalinograph data for HOT-228 can be
found in hot228ts.dat. 

The thermosalinograph data files do not contain any header information. Only
the data for each cruise are presented in the files. The order of variables 
in a thermosalinograph record are as follows: time (year, decimal year day),
longitude, latitude, temperature, salinity and quality. Note, negative 
longitude corresponds to West longitude. 

Data Record Format:

Column      Variable
-------     -------
1         Year
2         Decimal Year Day (January 1 = Year Day 0)
3         Longitude (decimal degrees)
4         Latitude (decimal degrees)
5         Temperature (Degrees Celsius,
          International Temperature Scale of 1990)
6         Salinity (1978 International Practical Salinity Scale)
7         Quality (defined by investigator) **

FORTRAN FORMAT  (i4, f10.5, f12.6, f11.6, f7.3, f7.3, i3)

** The quality word is the left-to-right concatenation of required quality 
bytes for temperature and salinity; the first byte represents temperature, 
the second represents salinity. Quality information is only available 
for cruises after HOT-71. 

The byte values are defined as follows: 

byte value      Definition
    2           Acceptable measurement.
    3           Questionable measurement.
    4           Bad measurement.

Sample File: (First few records) 

1996 142.40750 -157.994382  22.749950 25.313 34.877 23
1996 142.40762 -157.994536  22.749976 25.310 34.873 23
1996 142.40773 -157.994677  22.750001 25.309 34.876 23
1996 142.40785 -157.994831  22.750029 25.308 34.882 23


#DATASET SIZE:
130,705 kbytes

#NUMBER OF DATA UNITS:
11 unique cruises

#MISCELLANEOUS:
Previous HOT Bottle submissions to NODC:
NODC Accession                     Cruises  Years
9900208*                            1-100   1988-1998
0000639                             101-121 1999-2000
0001707                             122-154 2001-2003
0010624                             155-176 2004-2005
0041594                             177-188 2006
0048660                             189-198 2007
0055936                             199-206 2008
0069177                             208-217 2009
0087596                             218-227 2010
0101146                             228-238 2011
*includes JGOFS bio-chem parameters

Previous HOT CTD submissions to NODC:
NODC Accession                     Cruises  Years
9900206                             1-100   1988-1998
0000640                             101-121 1999-2000
0001704                             122-154 2001-2003
0010740                             155-176 2004-2005
0042029                             177-188 2006
0048725                             189-198 2007
0059482                             199-206 2008
0068957                             208-217 2009
0087584                             218-227 2010
0101727                             228-238 2011

Previous HOT thermosalinograph submissions to NODC:
NODC Accession                     Cruises  Years
9900213                             1-100   1988-1998
0000641                             101-121 1999-2000
0001710                             122-154 2001-2003
0011142                             155-176 2004-2005
0041849                             177-188 2006
0048896                             189-198 2007
0055943                             199-206 2008
0069501                             208-217 2009
0087988                             218-227 2010

Previous HOT/JGOFS Bio-Geo-Chem submissions to NODC:
NODC Accession                     Cruises  Years
0046427    *.gof                    1-198    1988-2007
0088839    *.gof                    199-227  2008-2010
0089168    *.flux, *.pp             1-227    1988-2010
