#ACCESSION NUMBER: 0087988 #CONTRIBUTOR: Dr. Roger Lukas #CONTRIBUTOR INSTITUTION: University of Hawaii Dept. of Oceanography 1000 Pope Road Honolulu, HI 96822 #ORIGINATOR: same #ORIGINATOR INSTITUTION: same #TITLE: Thermosalinograph Data of the Hawaii Ocean Time-series (HOT) program in the North Pacific 100 Miles North of Oahu, Hawaii for Cruises HOT219-227 during 2010 #PROJECT: Hawaii Ocean Time-series (HOT) HOT was initiated and funded through grants from the National Science Foundation under the auspices of the Joint Global Ocean Flux Study (JGOFS) and the World Ocean Circulation Experiment (WOCE). The field phase of these programs has ended, but support from the Ocean Sciences Division of NSF has enabled continuation of our basic HOT measurement program. The physical oceanographic 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. The US CLIVAR Office funded the physical oceanographic data during 2010. Support is also given by State of Hawaii general funds. #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 219-227 during 2010. CTD and Niskin bottle data from the same cruises are available in separate Accessions. Cruise 218 was a short cruise due to equipment problems and only has one ctd cast and no thermosalinograph data. #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: 21.1973 SOUTHERNMOST LATITUDE HEMISPHERE: N NORTHERNMOST LATITUDE: 23.1183 NORTHERNMOST LATITUDE HEMISPHERE: N WESTERNMOST LONGITUDE: 158.5691 WESTERNMOST LONGITUDE HEMISPHERE: W EASTERNMOST LONGITUDE: 157.7733 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 March 2010 - - 22 November 2010 #SAMPLING PERIODS: Year Crs# Start & End Dates Ship Chief Scientist ------------------------------------------------------------------------ 22 218* 15 Feb - 16 Feb 10 R/V K-O-K Curless 219 8 Mar - 12 Mar 10 R/V K-O-K Curless 220 5 Apr - 9 Apr 10 R/V K-O-K Mandujano 221 17 May - 21 May 10 R/V K-O-K Lethaby 222 7 Jun - 11 Jun 10 R/V K-O-K Curless 223 7 Jul - 11 Jul 10 R/V Kilo-Moana Curless 224 6 Aug - 10 Aug 10 R/V Kilo-Moana Curless 225 2 Sep - 6 Sep 10 R/V Kilo-Moana Lethaby 226 2 Oct - 6 Oct 10 R/V Kilo-Moana Nosse 227 20 Nov - 22 Nov 10 R/V Thompson Nosse *No THS data for cruise 218 #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. 2009 Fujieki, L.A., F. Santiago-Mandujano, Craig Nosse, R. Lukas, and M.Church. Hawaii Ocean Time-series Program Data Report 19, 2007. School of Ocean and Earth Science and Technology, Univ. of Hawaii, Honolulu, HI, December 2011. 192 pp #SUBMITTING MEDIUM: FTP #FILE FORMATS: Directories and files: /data root data directory /0-data Files as received by NODC from the originator thermosalinograph data. Filenaming convention: hotcccthsl.dat where ccc is cruise number thsl is 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-177 can be found in hot177thsl.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: 82,150 kbytes #NUMBER OF DATA UNITS: 9 unique cruises #MISCELLANEOUS: Previous HOTs Bottle submissions to NODC: NODC Accession Contents 9900208 HOTs 1988-1998 0000639 HOTs 1999-2000 0001707 HOTs 2001-2003 0010624 HOTs 2004-2005 0041594 HOTs 2006 0048660 HOTs 2007 0059936 HOTs 2008 0069177 HOTs 2009 0087596 HOTs 2010 Previous HOTs CTD submissions to NODC: NODC Accession Contents 9900206 HOTs 1988-1998 0000640 HOTs 1999-2000 0001704 HOTs 2001-2003 0010740 HOTs 2004-2005 0042029 HOTs 2006 0048725 HOTs 2007 0059842 HOTs 2008 0068957 HOTs 2009 0087584 HOTs 2010 Previous HOTs thermosalinograph submissions to NODC: NODC Accession Contents 9900213 HOTs 1988-1998 0000641 HOTs 1999-2000 0001710 HOTs 2001-2003 0011142 HOTs 2004-2005 0041849 HOTs 2006 0048896 HOTs 2007 0059943 HOTs 2008 0069501 HOTs 2009