gov.noaa.nodc:NCRMP-diel-HI eng utf8 series NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NOAA Contact Information Information for contacts at NCEI. information custodian 2026-07-10T14:33:21Z ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) National Coral Reef Monitoring Program: Diel seawater carbonate chemistry observations from a suite of instrumentation deployed at coral reef sites across the Hawaiian Archipelago 2019-04-12 publication 2026-07-07 revision 2019-03-27 creation International DOI Foundation (IDF) 10.25921/9p60-v204 NOAA National Centers for Environmental Information gov.noaa.nodc:NCRMP-diel-HI NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NCEI Contact Information Information for contacts at NCEI. information publisher Kevin Trick University of Hawaii Joint Institute for Marine and Atmospheric Research (JIMAR) Kevin.Trick@noaa.gov https://www.soest.hawaii.edu/cimar/ HTTPS University of Hawaii Joint Institute for Marine and Atmospheric Research (JIMAR) website Institution web page information resourceProvider Lori Luers NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division nmfs.pic.credinfo@noaa.gov https://www.pifsc.noaa.gov/ecosystem_sciences/ HTTPS NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division website Institution web page information resourceProvider NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division https://www.pifsc.noaa.gov/ecosystem_sciences/ HTTPS NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division website Institution web page information resourceProvider Kevin Trick NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division kevin.trick@noaa.gov https://www.pifsc.noaa.gov/ecosystem_sciences/ HTTPS NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division website Institution web page information collaborator Hannah C. Barkley NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division hannah.barkley@noaa.gov https://www.pifsc.noaa.gov/ecosystem_sciences/ HTTPS NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division website Institution web page information principalInvestigator Ecosystem Sciences Division, Pacific Islands Fisheries Science Center https://www.pifsc.noaa.gov/ecosystem_sciences/ HTTPS NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division website Institution web page information author NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division https://www.pifsc.noaa.gov/ecosystem_sciences/ HTTPS NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division website Institution web page information contributor tableDigital The ocean acidification diel suite is an autonomous instrument package that measures diel variability in coral reef seawater carbonate chemistry. Diel suite surveys are conducted by the NOAA Pacific Islands Fisheries Science Center (PIFSC), Ecosystem Sciences Division (ESD) within coral reef ecosystems across the Pacific Islands Region as part of the NOAA National Coral Reef Monitoring Program (NCRMP). The data provided in this record are from diel suites deployed across the Hawaiian Archipelago since 2016 during ESD-led NCRMP missions. Diel suites are deployed on the reef for at least 24 hours to measure chemical and physical parameters at each site. Each diel suite typically consists of various sensors and up to 9 Programmable Underwater Collectors (PUCs) and/or Sub-surface Automated Samplers (SAS). The oceanographic sensors of each diel suite measure parameters such as salinity, temperature, pressure, pH, current direction and magnitude, dissolved oxygen (DO), and/or photosynthetically active radiation (PAR). Seawater samples are collected in four-hour intervals for laboratory analyses of dissolved inorganic carbon (DIC) and total alkalinity (TA). Components of the carbonate system--including pH, pCO2 (partial pressure of carbon dioxide), and aragonite saturation state--are calculated from DIC, TA, temperature, salinity and pressure. Exceptions to the traditional diel suite survey and data collected are noted in each dataset as sensors could be added, removed, or have malfunctioned. Manual seawater sampling and other National Coral Reef Monitoring Program (NCRMP) field monitoring efforts are limited to daylight hour operations. As a result, these data sets do not capture full 24-hour variability in coral reef physical and chemical environments. The ocean acidification diel suite was developed to increase the temporal resolution and coverage of oceanographic and carbonate chemistry measurements and contextualize daytime sampling within the full diel cycle. The NOAA National Coral Reef Monitoring Program (NCRMP) details a long-term approach to provide an ecosystem perspective via monitoring climate, fish, benthic, and socioeconomic variables in a consistent and integrated manner. The NCRMP is intended to coordinate various NOAA Coral Reef Conservation Program (CRCP) biological, physical, and human dimensions activities into a cohesive NOAA-wide effort. Through the implementation of the NCRMP, NOAA will be able to clearly and concisely communicate results of national-scale monitoring to national, state, and territorial policy makers, resource managers, and the public on a periodic basis. NCRMP provides a framework for conducting sustained observations of biological, climate, and socioeconomic indicators at 10 priority coral reefs across the U.S. and its territories. This integrated approach consolidates monitoring of coral reefs under a uniform method in the Pacific, Atlantic, Caribbean, and the Gulf of Mexico for the first time. NCRMP is funded by the CRCP and supported by NOAA Fisheries, NOAA National Centers for Coastal Ocean Science (NCCOS), NOAA's Atlantic Oceanographic & Meteorological Laboratory (AOML), NOAA Coral Reef Watch, and many other partners. The Pacific Islands Fisheries Science Center (PIFSC), Ecosystem Sciences Division (ESD) at NOAA Fisheries is leading in-situ climate monitoring in the U.S. Pacific Islands Region as part of the ongoing Pacific Reef Assessment and Monitoring Program (RAMP). The climate component of NCRMP in the Pacific provides a comprehensive view of climate change impacts on coral reef ecosystems and helps identify areas of resilience and vulnerability. The key indicators used to identify and monitor climate-driven trends include 1) thermal stress caused by changes in sea temperature, 2) ocean acidification resulting from changes in carbonate chemistry, and 3) ecological impacts by collecting data on coral growth rates, erosion, and community structure to understand the impacts of thermal stress and ocean acidification on the ecosystem. Each year, ESD scientists work closely with CRCP and partners during Pacific RAMP missions to collect data using moored oceanographic (subsurface temperature recorders) and ecological (calcification accretion units [CAUs] and autonomous reef monitoring structures [ARMS]) instruments stationed at fixed sites in the Pacific Ocean, and water samples collected by divers. The in-situ data and satellite-based observations are also used in modeling efforts. Innovative analysis techniques are used to develop products that give fellow scientists, managers, decision makers and the public a better understanding of a region's resources and how they are changing over time. Funding Agency: NOAA Coral Reef Conservation Program completed historicalArchive NOAA National Centers for Environmental Information ncei.info@noaa.gov https://www.ncei.noaa.gov/contact HTTPS NCEI Contact Information Information for contacts at NCEI. information pointOfContact asNeeded https://www.ncei.noaa.gov/access/metadata/landing-page/bin/gfx?id=gov.noaa.nodc:NCRMP-diel-HI Preview graphic PNG 0186952 0240410 0316300 NCEI ACCESSION NUMBER 2026-06-17 publication ARAGONITE SATURATION STATE CONDUCTIVITY CURRENT DIRECTION CURRENT SPEED DEPTH - BOTTOM DEPTH - OBSERVATION DISSOLVED INORGANIC CARBON (DIC) DISSOLVED OXYGEN HYDROSTATIC PRESSURE partial pressure of carbon dioxide - water pH PHOTOSYNTHETIC ACTIVE RADIATION (PAR) SALINITY SALINITY - BOTTOM WATER SIGMA-T total alkalinity WATER TEMPERATURE theme NODC DATA TYPES THESAURUS ADCP coulometer for DIC measurement CTD - moored CTD oxygen sensor PAR Sensor pH sensor titrator instrument NODC INSTRUMENT TYPES THESAURUS chemical in situ laboratory analyses physical theme NODC OBSERVATION TYPES THESAURUS NOAA Ship Hi'ialakai NOAA Ship Oscar Elton Sette platform NODC PLATFORM NAMES THESAURUS NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division dataCentre NODC COLLECTING INSTITUTION NAMES THESAURUS NOAA Pacific Islands Fisheries Science Center, Ecosystem Sciences Division dataCentre NODC SUBMITTING INSTITUTION NAMES THESAURUS Coral Reef Conservation Program (CRCP) CORAL REEF STUDIES National Coral Reef Monitoring Program (NCRMP) NORTHWESTERN HAWAIIAN ISLANDS CORAL REEF ASSESSMENT PROGRAM (NOWRAMP) Pacific Reef and Assessment Monitoring Program (Pacific RAMP) project NODC PROJECT NAMES THESAURUS Coastal Waters of Hawaii Hawaiian Islands Humpback Whale National Marine Sanctuary North Pacific Ocean place NODC SEA AREA NAMES THESAURUS oceanography theme WMO_CategoryCode 2012-09-15 publication CRED CREP Coral Reef Ecosystem Division Coral Reef Ecosystem Program ESD Ecosystem Sciences Division PIFSC Pacific Islands Fisheries Science Center dataCentre Contributing Data Centers CRED CREP Coral Reef Ecosystem Division Coral Reef Ecosystem Program ESD Ecosystem Sciences Division PIFSC Pacific Islands Fisheries Science Center dataCentre Contributing Organizations DOC/NOAA/NMFS/PIFSC/ESD > Ecosystem Sciences Division, Pacific Islands Fisheries Science Center, National Marine Fisheries Service, NOAA, U.S. Department of Commerce dataCentre Global Change Master Directory (GCMD) Data Center Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian 743 National Coral Reef Monitoring Program (NCRMP) project CRCP Project Numeric Data Sets > Chemistry Numeric Data Sets > Oceanography theme CoRIS Discovery Thesaurus EARTH SCIENCE > Biosphere > Aquatic Habitat > Reef Habitat EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > In Situ Chemical EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > In Situ Physical EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs EARTH SCIENCE > Oceans > Ocean Chemistry > Alkalinity EARTH SCIENCE > Oceans > Ocean Chemistry > Calcification EARTH SCIENCE > Oceans > Ocean Chemistry > Carbon Dioxide > Partial Pressure EARTH SCIENCE > Oceans > Ocean Chemistry > Carbonate Chemistry EARTH SCIENCE > Oceans > Ocean Chemistry > Chemistry Monitoring and Assessment EARTH SCIENCE > Oceans > Ocean Chemistry > Climate Change EARTH SCIENCE > Oceans > Ocean Chemistry > Dissolution EARTH SCIENCE > Oceans > Ocean Chemistry > Dissolved Gases EARTH SCIENCE > Oceans > Ocean Chemistry > Dissolved Inorganic Carbon EARTH SCIENCE > Oceans > Ocean Chemistry > Ocean Acidification EARTH SCIENCE > Oceans > Ocean Chemistry > Oxygen EARTH SCIENCE > Oceans > Ocean Chemistry > Saturation State EARTH SCIENCE > Oceans > Ocean Chemistry > pH EARTH SCIENCE > Oceans > Ocean Circulation EARTH SCIENCE > Oceans > Ocean Circulation > Water Current Direction EARTH SCIENCE > Oceans > Ocean Circulation > Water Velocity EARTH SCIENCE > Oceans > Ocean Optics > Photosynthetically Active Radiation EARTH SCIENCE > Oceans > Ocean Temperature > Water Temperature EARTH SCIENCE > Oceans > Salinity/Density > Conductivity EARTH SCIENCE > Oceans > Salinity/Density > Density EARTH SCIENCE > Oceans > Salinity/Density > Salinity theme CoRIS Theme Thesaurus EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > WATER DEPTH EARTH SCIENCE > OCEANS > COASTAL PROCESSES > CORAL REEFS EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > ALKALINITY EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > CARBON DIOXIDE EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > CARBONATE EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > DISSOLVED GASES EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > INORGANIC CARBON EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > OXYGEN EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > PH EARTH SCIENCE > OCEANS > OCEAN CIRCULATION EARTH SCIENCE > OCEANS > OCEAN CIRCULATION > OCEAN CURRENTS EARTH SCIENCE > OCEANS > OCEAN OPTICS > PHOTOSYNTHETICALLY ACTIVE RADIATION EARTH SCIENCE > OCEANS > OCEAN PRESSURE > WATER PRESSURE EARTH SCIENCE > OCEANS > OCEAN TEMPERATURE > WATER TEMPERATURE EARTH SCIENCE > OCEANS > SALINITY/DENSITY > CONDUCTIVITY EARTH SCIENCE > OCEANS > SALINITY/DENSITY > DENSITY EARTH SCIENCE > OCEANS > SALINITY/DENSITY > SALINITY theme Global Change Master Directory (GCMD) Science Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian ADCP > Acoustic Doppler Current Profiler COULOMETERS CTD > Conductivity, Temperature, Depth OXYGEN METERS > OXYGEN METERS PAR SENSORS > Photosynthetically Active Radiation Sensors PH METERS > PH METERS instrument Global Change Master Directory (GCMD) Instrument Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian Acoustic Doppler Current Profiler (ADCP) Dive Computer Moored CTD Programmable Underwater Collector (PUC) Sub-surface Automated Samplers (SAS) Tilt Current Meter (TCM) instrument Provider Instruments Ships platform Global Change Master Directory (GCMD) Platform Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian Hi'ialakai (call sign: WTEY, ICES code: 33HL, 2004-) OSCAR ELTON SETTE (call sign: WTEE, ICES code: 33OC, 2003-) platform ICES/SeaDataNet Ship Codes COUNTRY/TERRITORY > United States of America > Hawaii > Hawaii > Hawaii Island (19N155W0003) COUNTRY/TERRITORY > United States of America > Hawaii > Honolulu > Kure Atoll (28N178W0001) COUNTRY/TERRITORY > United States of America > Hawaii > Honolulu > Lisianski Island (25N173W0001) COUNTRY/TERRITORY > United States of America > Hawaii > Honolulu > Northwestern Hawaiian Islands (28N178W0000) COUNTRY/TERRITORY > United States of America > Hawaii > Maui > Lanai Island (20N156W0002) COUNTRY/TERRITORY > United States of America > Hawaii > Maui > Maui Island (20N156W0004) OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Hawaiian Islands > Hawaii Island > Hawaii Island (19N155W0003) OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Hawaiian Islands > Lanai Island > Lanai Island (20N156W0002) OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Hawaiian Islands > Maui Island > Maui Island (20N156W0004) OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Northwestern Hawaiian Islands (28N178W0000) OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Northwestern Hawaiian Islands > Kure Atoll (28N178W0001) OCEAN BASIN > Pacific Ocean > Central Pacific Ocean > Northwestern Hawaiian Islands > Lisianski Island (25N173W0001) place CoRIS Place Thesaurus OCEAN > PACIFIC OCEAN > CENTRAL PACIFIC OCEAN > HAWAIIAN ISLANDS OCEAN > PACIFIC OCEAN > NORTH PACIFIC OCEAN place Global Change Master Directory (GCMD) Location Keywords 2026 revision 24 Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA) Greenbelt MD https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords HTTPS GCMD Keyword Forum Page Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords information custodian 5MLK76 8RR0EL ME20PL Send2NCEI Submission Package ID accessLevel: public otherRestrictions Cite as: Ecosystem Sciences Division, Pacific Islands Fisheries Science Center (2019). National Coral Reef Monitoring Program: Diel seawater carbonate chemistry observations from a suite of instrumentation deployed at coral reef sites across the Hawaiian Archipelago. [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/9p60-v204. Accessed [date]. Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives. otherRestrictions Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose. license Some of the data in this dataset has been dedicated to the public domain under the Creative Commons CC0 1.0 Universal (CC0 1.0) Public Domain Dedication. SPDX License: Creative Commons Zero v1.0 Universal (CC0-1.0) eng; USA utf8 environment oceans -178.341 -155.90137 19.20991 28.3851 2016-09-14 2024-07-22 Accessions: 0186952, 0240410, 0316300 NOAA National Centers for Environmental Information +1-301-713-3277 ncei.info@noaa.gov pointOfContact In most cases, electronic downloads of the data are free. However, fees may apply for custom orders, data certifications, copies of analog materials, and data distribution on physical media. Contact NCEI for other distribution options and instructions. CSV 54.604 https://doi.org/10.25921/9p60-v204 HTTPS Web browser NCEI Dataset Landing Page Navigate directly to the URL for a descriptive web page with download links. information https://www.ncei.noaa.gov/metadata/granule/geoportal/?from=0&size=10&esdsl=%7B%22query%22%3A%7B%22bool%22%3A%7B%22must%22%3A%5B%7B%22query_string%22%3A%7B%22analyze_wildcard%22%3Atrue%2C%22query%22%3A%22fileid%3ANCRMP-diel-HI.*%22%7D%7D%5D%7D%7D%7D#searchPanel HTTPS Web browser Granule Search Search for data granules belonging to this collection (a granule is the smallest aggregation of data that can be independently described and retrieved). search series NCEI Accession 0186952 v1.1 was published. 2019-04-12T21:47:14Z NCEI Accession 0186952 was revised and v2.2 was published. 2021-09-14T21:27:20Z NCEI Accession 0240410 v1.1 was published. 2021-09-24T12:11:21Z NCEI Accession 0316300 v1.1 was published. 2026-07-07T20:02:31Z asNeeded Metadata are developed, maintained and distributed by NCEI. Updates are performed as needed to maintain currentness. NOAA National Centers for Environmental Information custodian ADCP ADCP Acoustic Doppler Current Profiler The Acoustic Doppler Current Profiler (ADCP) measures currents beneath a ship while underway. Sound signals sent from the moving ship bounce back to receivers aboard the ship. This provides a profile of water movement relative to the ship-precise modern navigation, allowing the ship's motion to be subtracted from the data. These devices are also used on moorings and profilers and, along with acoustic backscattering, measure animal biomass. Particles in the path of the sound waves, mostly plankton, reflect a small part of the sound energy back toward receivers, allowing researchers to make remote estimates of the sizes and numbers of animals present in the water column. Before the 1970's, the most technologically advanced instrument used to measure water velocity was known as a Doppler speed log. This evolved into the first commercial ADCP, produced in the mid-1970's, which used averaging. Later in the 1970's, the first vessel-mounted ADCP was developed to measure water velocity more accurately and to allow measurement in range cells over a depth profile. As instruments evolved, so did new techniques in Doppler signal processing. Initially, Doppler speed logs used simple analog signal processing methods, which are still used in some commercial speed logs today. However, the first ADCPs incorporated analog-to-digital signal conversion over a narrow communication bandwidth. Around 1990, this technique was developed into broadband signal processing. Since then, broadband ADCPs have been able to generate very accurate, real-time velocity measurements. coulometer for DIC measurement coulometer for DIC measurement measures dissolved inorganic carbon (DIC) A known amount of seawater is dispensed into a stripping chamber where it is acidified and purged with an inert gas. The amount of CO2 in the resulting gas stream is determined by absorbing the CO2 in an absorbent. The pH of the solution is monitored by measuring the transmittance . CTD - moored CTD CTD - moored CTD CTD - moored CTD oxygen sensor oxygen sensor Any instrument that measures oxygen content in a compound. PAR Sensor PAR Sensor Photosynthetically Active Radiation Sensor The PAR sensor measures global solar radiation from 400 to 700 nm, which approximates the spectral band active in photosynthesis. The response of the instrument falls sharply to zero on either side of this band, and between 400 and 670 nm it increases monotonically from about 50% to 100%. There is no protective glass dome over the receiving surface. Irradiance from the sun passes through a small white visible bandpass filter/diffuser in the shape of a horizontal disk at the top of the instrument. Within the instrument radiation is directed through a series of colored glass filters and onto a silicon photodiode detector. The factory-supplied calibration converts the signal from the detector to a flux of photons in micro-mole (of photons) s-1 m-2. (One micro-mole equals 6.022 E17 photons.) For the solar spectrum, these units may be converted to watts per square meter by dividing by 4.6. (http://www.srrb.noaa.gov/instrument/par.htm) pH sensor pH sensor generic meter used to measure pH Any of a class of instruments used to quantify pH in a water or other type of sample. titrator titrator titrator NOAA Ship Hi'ialakai Title: NOAA Ship Flag: United States of America Vessel Type: Research Vessel DOB: Nov 1984 IMO: 8835619 Hull No: R 334 Former Name: Vindicator (2004) Commissioned by NOAA in 2002 Submitted to ICES on 2012-12-13. NOAA Ship Oscar Elton Sette Title: NOAA Ship Flag: United States of America Vessel Type: Research Vessel; Ice Strengthened DOB: Aug 1988 IMO: 8835097 Former Name: ADVENTUROUS (2003) http://www.moc.noaa.gov/os/index.html Submitted to ICES on 2013-12-18.