#ACCESSION NUMBER: 0101146 #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: Niskin bottle 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. Samples of water column chemical analyses were collected mostly in the upper 1000m using Niskin bottles mounted on a rosette. The strategy was to sample at density horizons within the main thermocline at pressure horizons above and below this region (i.e., <150 dbar and >2000 dbar). Care was applied to ensure the highest possible accuracy and precision. This NODC accession contains Niskin Bottle data for HOT cruises 228-238 during 2011. CTD and thermosalinograph data from the same cruises are available in separate NODC accessions. Historic data for HOT have also been archived at NODC. Cruise 228 returned to port two days early due to winch problems. Only three hydrographic casts were made. #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: 21.25667 SOUTHERNMOST LATITUDE HEMISPHERE: N NORTHERNMOST LATITUDE: 22.82017 NORTHERNMOST LATITUDE HEMISPHERE: N WESTERNMOST LONGITUDE: 158.36583 WESTERNMOST LONGITUDE HEMISPHERE: W EASTERNMOST LONGITUDE: 157.91066 EASTERNMOST LONGITUDE HEMISPHERE: W #LOCATION KEYWORDS: Hawaii, North Pacific Ocean #SAMPLING STATIONS: 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 January 2011 - 22 December 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 *Note, HOT cruise 228 was cut short due to winch problems. #PARAMETERS: Bottle: CTD Pressure (Decibars) CTD Temperature (ITS-90) CTD Salinity (PSU-78) CTD Oxygen (umol/kg) Potential Temperature (ITC-90) Potential Density (kg/m3) Bottle Salinity (PSS-78) Bottle Oxygen (umol/kg) Phosphate (PO4) (umol/kg) Nitrate + Nitrite (NO2+NO3) (umol/kg) Silicate (SiO4) (umol/kg) #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. Water samples are collected during HOT cruises using a 24 place rosette. Samples of salinity, oxygen, phosphate, nitrate and silicate are regularly taken from both shallow and deep water casts. Salinity samples are taken back to the University of Hawaii where they are measured using an Autosal salinometer . Phosphate, nitrate and silicate samples are also measured at the University of Hawaii while oxygen measurements are conducted aboard ship during the cruises. 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). #INSTRUMENT TYPES: i) CTD The underwater CTD hardware consists of a main pressure housing containing power supplies, acquisition electronics, telemetry circuitry, and a pressure transducer. This system has the ability to acquire various channels of data at the rate of 24 scans per second. It has five frequency encoded channels for two temperature, two conductivity and one pressure sensors, and eight A/D channels for oxygen sensors, fluorometer and altimeter. The suite of modular sensors is attached externally. The three primary sensors used during WOCE/JGOFS work are a temperature sensor, a conductivity sensor for measuring salinity, and a dissolved oxygen sensor. An underwater pump is connected to the temperature sensor and conductivity cell via a tc-duct, which then connects to the oxygen sensor to provide rapid and constant flow of water past the sensors. The Sea-Bird 9/11 Plus system provides us with a redundant set of temperature, conductivity and oxygen sensors connected to another pump. In addition we have the ability to measure natural fluorescence using a Sea-Tech Flash Fluorometer. For deep casts a Datasonics programmable sonar altimeter (Model PSA-900) is connected to the CTD. ii) SeaBird Carousel The SeaBird carousel is an electro-mechanical device that uses a magnetic trigger to trip Niskin bottles upon command. This is accomplished when the release device inside the carousel housing receives a signal from the SeaBird deck box, which causes it to advance one position per command. This in turn releases the lanyard for a specific Niskin bottle, assuming the bottles were cocked beforehand. iii) Niskin bottles It is part of the pre-cruise preparations to log the rosette configuration which matches Niskin bottles with rosette position. An update of this information should be done in the Science Log if the Niskin bottles are changed for any reason. Note that the rigging of Niskin lanyards and inspection of Niskin bottles requires considerable experience to be done properly. Water samples were collected using a 24-place aluminum rosette manufactured by Scripps Institution of Oceanography's Oceanographic Data Facility (ODF). Twelve-liter polyvinylchloride sampling bottles, also made by ODF, were used on this rosette. These sample bottles were equipped with Buna-N rubber O-rings, teflon-coated steel springs and standard General Oceanics samping valves. #REFERENCES: 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 /bottle Bottle data. Filenaming convention: hotccc.sea where ccc is cruise number /woce_sum WOCE-type sum file which gives details on position and parameters taken of each cast and station of each cruise. Filenaming convention: hotccc.sum where ccc is cruise number BOTTLE FORMAT: Format for *.sea files: ----------------------- Welcome to the HOT Water Sample Data Base Water sample data from HOT are written according to the *.sea files specified by the WOCE Hydrographic Programme Office, for submission of these data to the WHP. One file is written for each HOT cruise (e.g., hot1.sea contains the data from HOT-1). Files from the ALOHA-Climax (AC) cruises have the prefix ac (e.g., ac1.sea contains the data from AC-1). Formats for these files are detailed in the WHP Office Report WHPO 90-1, available from Steve Diggs, WHPO Data Manager, Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, CA 92093-0214. The files are self-explanatory, one column is written for each measured parameter. Missing data are filled with -9. A 5-line heading labels each column. The first year's temperatures are reported in IPTS-68. Subsequent temperature are reported in ITS-90 units. Since temperature sensor calibrations were done in IPTS-68 units, and the UNESCO routines require IPTS-68 temperature, all intermediate processing was done in IPTS-68. As a final step, temperature and potential temperature were converted to ITS-90 using t_90 = 0.99976 t_68. Variables having 7 asterisks on the 4th heading line have a quality flag associated with them. These 1-digit quality flags are concate- nated to form quality word which is listed as the last variable in each row. The values each digit can assume and their meanings are listed below: Bottle quality flag definitions: Byte Value Definition 1 Not assigned. 2 No problems noted. 3 Leaking. 4 Did not trip correctly. 5-8 Not assigned. 9 Samples not drawn from this bottle. Water sample quality flag definitions: Byte Value Definition 1 Sample for this measurement was drawn from water bottle but analysis not received. 2 Acceptable measurement. 3 Questionable measurement. 4 Bad measurement. 5 Not reported. 6 Mean of replicate measurements. 7 Manual chromatographic peak integration. 8 Irregular digital chromatographic peak integration. 9 Sample not drawn for this measurement from this bottle. #DATASET SIZE: 574 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 *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 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