#TEMPORARY ACCESSION NUMBER: #ACCESSION NUMBER: #CONTRIBUTOR: Dr. Roger Lukas #CONTRIBUTOR INSTITUTION: University of Hawaii Dept. of Oceanography 1000 Pope Road Honolulu, HI 96822 #ORIGINATOR: same #ORIGINATOR INSTITUTION: same #TITLE: Niskin Bottle Data of the Hawaii Ocean Time-series (HOT) program in the North Pacific 100 Miles North of Oahu, Hawaii for Cruises HOT208-217 during 2009 #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 2009. #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 208-217 during 2009. CTD and thermosalinograph data from the same cruises are available in separate Accessions. HOT 207 cruise was cut short due to a problem with the winch. No data are available. #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: 21.3423 SOUTHERNMOST LATITUDE HEMISPHERE: N NORTHERNMOST LATITUDE: 22.8438 NORTHERNMOST LATITUDE HEMISPHERE: N WESTERNMOST LONGITUDE: 158.365 WESTERNMOST LONGITUDE HEMISPHERE: W EASTERNMOST LONGITUDE: 157.8792 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: 19 January 2009 - 12 December 2009 #SAMPLING PERIODS: Year Crs# Start & End Dates Ship Chief Scientist ------------------------------------------------------------------------ 2009 208 19 Jan - 23 Jan 09 R/V Kilo-Moana Mandujano 209 16 Feb - 20 Feb 09 R/V Kilo-Moana Lethaby 210 27 Apr - 1 May 09 R/V Knorr Grabowski 211/ST-15A 26 May - 30 May 09 R/V K-O-K Mandujano 212 2 Jul - 6 Jul 09 R/V Kilo-Moana Curless 213 23 Jul - 27 Jul 09 R/V Kilo-Moana Curless 214 17 Aug - 21 Aug 09 R/V Kilo-Moana Lethaby 215 23 Sep - 27 Sep 09 R/V K-O-K Curless 216 2 Nov - 6 Nov 09 R/V K-O-K Lethaby 217 8 Dec - 12 Dec 09 R/V K-O-K Mandujano #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: 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. 2007 Fujieki, L.A., F. Santiago-Mandujano, P. Lethaby, R. Lukas, and D. Karl. Hawaii Ocean Time-series Program Data Report 19, 2007. School of Ocean and Earth Science and Technology, Univ. of Hawaii, Honolulu, HI, June 2010. 403 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: 670 Kbytes #NUMBER OF DATA UNITS: 10 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 0055936 HOTs 2008 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 0059482 HOTs 2008 0068957 HOTs 2009 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 0055943 HOTs 2008