gov.noaa.nodc:0188506 eng utf8 dataset 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 2026-07-30T13:06:22Z ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) Dissolved inorganic carbon, total alkalinity, pH, nutrients, and other variables collected from discrete profile observations in the southwest coast of Puerto Rico from 2009-01-16 to 2025-12-04 (NCEI Accession 0188506) 2019-05-10 publication 2026-07-24 revision 2019-05-06 creation International DOI Foundation (IDF) 10.25921/51y4-6409 NOAA National Centers for Environmental Information gov.noaa.nodc:0188506 NCEI Archive Management System 0188506 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 Erick M. García-Troche University of Puerto Rico at Mayagüez (UPRM) erick.garcia1@upr.edu https://www.uprm.edu/ HTTPS University of Puerto Rico at Mayagüez (UPRM) website Institution web page information resourceProvider University of Puerto Rico at Mayagüez (UPRM) https://www.uprm.edu/ HTTPS University of Puerto Rico at Mayagüez (UPRM) website Institution web page information resourceProvider Julio M. Morell University of Puerto Rico at Mayagüez, Department of Marine Sciences julio.morell@upr.edu principalInvestigator Melissa Meléndez University of Hawaiʻi at Mānoa (UHM) https://manoa.hawaii.edu/ HTTPS University of Hawaiʻi at Mānoa (UHM) website Institution web page information collaborator Joseph Salisbury University of New Hampshire (UNH) Joe.Salisbury@unh.edu collaborator Erick M. García-Troche University of Puerto Rico (UPR) erick.garcia1@upr.edu collaborator Meléndez, Melissa University of Hawaiʻi at Mānoa https://manoa.hawaii.edu/ HTTPS University of Hawaiʻi at Mānoa (UHM) website Institution web page information author García-Troche, Erick M. University of Puerto Rico (UPR) erick.garcia1@upr.edu author Morell, Julio M. University of Puerto Rico at Mayagüez, Department of Marine Sciences julio.morell@upr.edu author Salisbury, Joseph E. University of New Hampshire author University of Puerto Rico at Mayagüez (UPRM) https://www.uprm.edu/ HTTPS University of Puerto Rico at Mayagüez (UPRM) website Institution web page information contributor tableDigital This time series dataset includes weekly and bi-weekly discrete seawater samples of pH and total alkalinity, dissolved inorganic carbon, phosphates and profile measurements of temperature and salinity from 2009 to 2025. These are used to track the dynamics and controls on local carbon chemistry at the southwest part of Puerto Rico in support of the ocean acidification and water quality research in regional coastal and near-shore zones. Some of these environmental parameters have been monitored since 2009 when the National Oceanic and Atmospheric Administration (NOAA) Coral Health and Monitoring Program established the Atlantic Ocean Acidification Test-Bed (AOAT) at the Marine Reserve of La Parguera, Puerto Rico. As a key part of this project, a moored autonomous pCO_2 system (MAPCO2) was deployed along the fore-reef of Enrique shelf reef and a discrete sampling at the Marine Reserve for data validation and calibration commenced. This monitoring effort supports the requirements of the recent implementation of La Parguera as a Class III climate and ecosystem monitoring station through the National Coral Reef Monitoring Program (NCRMP) in support of the NOAA Coral Reef Conservation Program (CRCP) and the Ocean Acidification Program (OAP). Biweekly calibration/validation discrete sampling to support the MapCO2 mooring at La Parguera, Puerto Rico and the National Coral Reef Monitoring Program (NCRMP) Funding Information: NOAA Ocean Acidification Program (NOA-ON La Parguera (Morell, CARICOOS), NOAONFY2123.LaParguera) Funding Information: NOAA Ocean Acidification Program (NOA-ON La Parguera (Morell, CARICOOS), OAP1817-1033) Funding Information: NOAA National Coral Reef Monitoring Program - Ocean Acidification Enterprise (Sustained monitoring of near-reef carbonate chemistry at the Atlantic Ocean Acidification NCRMP Class III Station, La Parguera, Puerto Rico) 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 NCEI Accession 0188506 was revised and a new version of the archival package was published. Updates to existing archival packages may provide additional files or replace obsolete files. The latest version contains the most complete and up-to-date representation of this archival information package. All of the files received prior to this update are available in the preceding version of this accession. Please see journal.txt in the /about directory for additional details on changes made. https://www.ncei.noaa.gov/access/metadata/landing-page/bin/gfx?id=gov.noaa.nodc:0188506 Preview graphic PNG 0188506 NCEI ACCESSION NUMBER 2026-07-23 publication DISSOLVED INORGANIC CARBON (DIC) NITRATE pH phosphate Potential temperature (theta) SALINITY SIGMA-THETA silicate total alkalinity WATER TEMPERATURE theme NODC DATA TYPES THESAURUS CTD Niskin bottle Non-dispersive infrared (NDIR) dissolved inorganic carbon (DIC) analyzer spectrophotometer thermosalinograph titrator instrument NODC INSTRUMENT TYPES THESAURUS discrete sample profile theme NODC OBSERVATION TYPES THESAURUS University of Puerto Rico at Mayagüez dataCentre NODC COLLECTING INSTITUTION NAMES THESAURUS University of Puerto Rico at Mayagüez dataCentre NODC SUBMITTING INSTITUTION NAMES THESAURUS CORAL REEF STUDIES NODC Ocean Acidification Scientific Data Stewardship (OADS) US DOC; NOAA; Office of Oceanic and Atmospheric Research; Ocean Acidification Program (OAP) project NODC PROJECT NAMES THESAURUS Caribbean Sea place NODC SEA AREA NAMES THESAURUS oceanography theme WMO_CategoryCode 2012-09-15 publication Time series project Cruise ID Ocean Acidification Program (OAP) Ocean Carbon and Acidification Data System (OCADS) Project project Ocean Acidification Search Keywords EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > ALKALINITY EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > INORGANIC CARBON EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > NITRATE EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > PH EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > PHOSPHATE EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > SILICATE EARTH SCIENCE > OCEANS > OCEAN TEMPERATURE > POTENTIAL TEMPERATURE EARTH SCIENCE > OCEANS > OCEAN TEMPERATURE > WATER TEMPERATURE 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 Discrete measurement Profile theme OCADS Study Type CTDPRS_DBAR CTDSAL_PSS78 CTDTMP_ITS90_DEG_C DEPTH_BTM_METER DEPTH_METER DIC_umol_KG NITRATE_UMOL_KG PHOSPHATE_UMOL_KG PH_TOT_INSITU SIGMATHETA_KG_M3 SILICATE_UMOL_KG TA_umol_KG THETA_DEG_C theme Provider Variable Abbreviations CO2NDIR > Carbon Dioxide Nondispersive Infrared Analyzer CTD > Conductivity, Temperature, Depth NISKIN BOTTLES OPTSPEC > Optical Spectrometer THERMOSALINOGRAPHS 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 OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN > CARIBBEAN SEA 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 Caribbean Sea place Provider Geographic Names accessLevel: public otherRestrictions Cite as: Meléndez, Melissa; García-Troche, Erick M.; Morell, Julio M.; Salisbury, Joseph E. (2019). Dissolved inorganic carbon, total alkalinity, pH, nutrients, and other variables collected from discrete profile observations in the southwest coast of Puerto Rico from 2009-01-16 to 2025-12-04 (NCEI Accession 0188506). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/51y4-6409. 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. Meléndez, Melissa; García-Troche, Erick M.; Morell, Julio M.; Salisbury, Joseph E. (2016). Dissolved inorganic carbon, total alkalinity, pH, phosphate, dissolved oxygen, and other variables collected from surface discrete observations using Niskin bottle and other instruments from R/V Sultana in the southwest coast of Puerto Rico from 2009-01-05 to 2021-03-19 (NCEI Accession 0145164). NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.7289/v52j68zc. 2016-03-10 publication International DOI Foundation (IDF) https://doi.org/10.7289/v52j68zc NOAA National Centers for Environmental Information gov.noaa.nodc:0145164 https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0145164.html HTTPS https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0145164.html Related dataset information Meléndez, Melissa University of Hawaiʻi at Mānoa https://manoa.hawaii.edu/ HTTPS University of Hawaiʻi at Mānoa (UHM) website Institution web page information author García-Troche, Erick M. University of Puerto Rico (UPR) erick.garcia1@upr.edu author Morell, Julio M. University of Puerto Rico at Mayagüez, Department of Marine Sciences julio.morell@upr.edu author Salisbury, Joseph E. University of New Hampshire author NOAA National Centers for Environmental Information (NCEI) publisher tableDigital crossReference project NOAA National Centers for Environmental Information (2022). Ocean Carbon and Acidification Data System (OCADS). NOAA National Centers for Environmental Information. https://www.ncei.noaa.gov/products/ocean-carbon-acidification-data-system 2022-04 publication https://www.ncei.noaa.gov/products/ocean-carbon-acidification-data-system HTTPS https://www.ncei.noaa.gov/products/ocean-carbon-acidification-data-system OCADS website information NOAA National Centers for Environmental Information author NOAA National Centers for Environmental Information (NCEI) publisher documentDigital [accessed 2024-02-08] crossReference program eng; USA utf8 environment oceans -67.0942 -67.0336 17.38 17.975 2009-01-16 2025-12-04 In this accession, NCEI has archived multiple versions of these data. The latest (and best) version of these data has the largest version number. 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. Originator data format 0.524 https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0188506.html HTTPS Web browser Project Metadata Navigate directly to the URL for a descriptive web page with download links. information https://doi.org/10.25921/51y4-6409 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/archive/accession/oas/188506 HTTPS Web browser Descriptive Information Navigate directly to the URL for a descriptive web page with download links. information https://www.ncei.noaa.gov/archive/accession/download/188506 HTTPS Web browser HTTPS Navigate directly to the URL for data access and direct download. download ftp://ftp-oceans.ncei.noaa.gov/nodc/archive/arc0136/0188506/ FTP Any FTP client FTP These data are available through the File Transfer Protocol (FTP). FTP is no longer supported by most internet browsers. You may copy and paste the FTP link to the data into an FTP client (e.g., FileZilla or WinSCP). download dataset NCEI Accession 0188506 v1.1 was published. 2019-05-10T20:50:18Z NCEI Accession 0188506 v1.1 publication https://www.ncei.noaa.gov/archive/accession/0188506/1.1 HTTPS NCEI Accession 0188506 v1.1 published 2019-05-10T20:50:18Z download NCEI Accession 0188506 was revised and v2.2 was published. Updates were received for this dataset. These updates were copied into the data/0-data/ directory of this accession. These updates may provide additional files or replace obsolete files. This version contains the most complete and up-to-date representation of this archival information package. All of the files received prior to this update are available in the preceding version of this accession. 2025-04-24T21:34:37Z NCEI Accession 0188506 v2.2 publication https://www.ncei.noaa.gov/archive/accession/0188506/2.2 HTTPS NCEI Accession 0188506 v2.2 published 2025-04-24T21:34:37Z download NCEI Accession 0188506 was revised and v3.3 was published. Updates were received for this dataset. These updates were copied into the data/0-data/ directory of this accession. These updates may provide additional files or replace obsolete files. This version contains the most complete and up-to-date representation of this archival information package. All of the files received prior to this update are available in the preceding version of this accession. 2026-07-24T19:43:50Z NCEI Accession 0188506 v3.3 publication https://www.ncei.noaa.gov/archive/accession/0188506/3.3 HTTPS NCEI Accession 0188506 v3.3 published 2026-07-24T19:43:50Z download dataset Parameter or Variable: Dissolved Inorganic Carbon; Abbreviation: DIC_umol_KG; Unit: umol/kg; Observation type: Discrete water sample; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: Measured; Calculation method and parameters: none; Sampling instrument: Van Dorn Bottle; Analyzing instrument: Apollo SciTech AS-C2 automated analyzer; Detailed sampling and analyzing information: DIC samples were analyzed at UNH by measuring the infrared absorption of the CO_2 released upon the acidification of the sample with 10% phosphoric acid using an Apollo SciTech AS-C2 automated DIC analyzer. The instrument and method precision as implemented was plus/minus 2 umol kg-1.; Standardization frequency: Calibration is at the beginning of the day. Standard checks are done every 5 samples and at the end of the day.; CRM manufacturer: Andrew Dickson's laboratory at Scripps Institute of Oceanography; CRM batch number: Multiple Batches; Preservation method: Saturated Mercury Chloride (HgCl_2); Preservative volume: 25 uL; Preservative correction: no correction; Quality flag convention: 1-Not Analyzed; 2-Good; 3-Questionable, 4-Bad; 5-Not reported; 6-Duplicate. Samples values that are not reported appear as -999 with the corresponding flag number 5.; Method reference: Dickson, A.G., Sabine, C.L. and Christian, J.R. (Eds.) 2007. Guide to best practices for ocean CO2 measurements. PICES Special Publication 3, 191 pp.; Researcher name: Joseph Salisbury; Researcher institution: University of New Hampshire Parameter or Variable: Total alkalinity; Abbreviation: TA_umol_KG; Unit: umol/kg; Observation type: Discrete water sample; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: Measured; Calculation method and parameters: none; Sampling instrument: Van Dorn Bottle; Analyzing instrument: Custom-built Gran titration system by Dr. Chirs Langdon for samples analyzed at UPRM (2009 - June 2014). Automated titrator with a Orion 3-Star pH electrode (Thermo Fisher Inc.) for samples analyzed at UNH (Jul 2014 - present).; Type of titration: Gran titration; Cell type (open or closed): Open; Detailed sampling and analyzing information: UPRM - The Dickson Certified Reference Materials were used to standardize the nominal 0.1 M hydrochloric acid (HCl) titrant at a rate of 0.2515 uL per step. The uncertainty of the instrument and analytical methods as implemented were +/- 1-2 umol kg-1 SW. UNH - TA is measuring by Gran titration with 0.1 N HCl using an automated titrator. The pH electrode use in the TA titration is an Orion 3-Star, Thermo Fisher Inc., calibrated using three low ionic strength pH buffers certified on the U.S. National Bureau of Standards (NBS) scale to +/- 0.01.; Standardization description: UPRM - 0.1 M hydrochloric acid (HCl) was standarized with Dickson CRMs and sample triplicates. UNH- Calibrated with multiple batches of the Dickson CRM; Standardization frequency: UPRM - Calibration was at the beginning of the analysis. UNH - Calibration is at the beginning of the day. Standard checks are done every 5 samples and at the end of the day.; CRM manufacturer: Andrew Dickson's lab at Scripps Institute of Oceanography; CRM batch number: Multiple batches; Preservation method: Saturated Mercury Chloride (HgCl_2); Preservative volume: 50 uL for 250 mL bottles, 25 uL for 125 bottles and 12 uL for 60 mL bottles; Preservative correction: no correction.; TA blank correction: none; Uncertainty: UPRM from 1 to 2 umol kg-1 and UNH between 3 to 4 umol kg-1; Quality flag convention: 1-Not Analyzed; 2-Good; 3-Questionable, 4-Bad; 5-Not reported; 6-Duplicate. Samples values that are not reported appear as -999 with the corresponding flag number 5.; Method reference: Dickson, A.G., Sabine, C.L. and Christian, J.R. (Eds.) 2007. Guide to best practices for ocean CO2 measurements. PICES Special Publication 3, 191 pp.; Researcher name: Julio Morell; Joseph Salisbury; Researcher institution: University of Puerto Rico at Mayaguez; University of New Hampshire Parameter or Variable: pH; Abbreviation: PH_TOT_INSITU; pH scale: Total; Observation type: Discrete water sample; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: Measured; Calculation method and parameters: none; Sampling instrument: Van Dorn Bottle; Analyzing instrument: Shimadzu 1601 and Shimadzu 1800 spectrophotometers; Temperature of pH measurement: laboratory ambient temperature (~21degC); Detailed sampling and analyzing information: The pH analysis are accomplished within 24 hours of sampling, if not the sample is preserved with a saturated solution of mercury chloride. M-cresol purple is used as the indicator dye and absorbances are recorded at 434, 578 and 780 nm (2009-2016); and 434, 488,578 and 730-750 nm (2017-present). Methanol and distilled water are used to rinse between runs. The pH value is calculated considering the Henderson-Hasselbalch and Beer-Lambert Law equations, in-situ salinities and temperatures, laboratory temperature and extinction coefficients for the dye. Each sample is analyzed in triplicate in 10 cm pathlength quartz cylindrical cells with distilled water in the background over a wavelength range to 425 to 790 nm at 1.0 nm intervals.; Standardization description: none; Standardization frequency: none; pH standard values: none; Temperature of standardization: none; Temperature correction method: Liu, X., Patsavas, M.C., Byrne R.H. 2011. Purification and characterization of meta-cresol purple for spectrophotometric seawater pH measurements. Environ Sci Technol. 45(11), p. 4862-4868.; At what temperature was pH reported: in-situ temperature; Quality flag convention: 1-Not Analyzed; 2-Good; 3-Questionable, 4-Bad; 5-Not reported; 6-Duplicate. Samples values that are not reported appear as -999 with the corresponding flag number 5.; Method reference: Dickson, A.G., Sabine, C.L. and Christian, J.R. (Eds.) 2007. Guide to best practices for ocean CO2 measurements. PICES Special Publication 3, 191 pp.; Researcher name: Julio Morell; Researcher institution: University of Puerto Rico at Mayaguez Parameter or Variable: Hydrostatic pressure recorded from CTD at the depth where the sample is taken; Abbreviation: CTDPRS_DBAR; Unit: dbar; Observation type: Profile; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: measured; Calculation method and parameters: none; Sampling instrument: SBE25 CTD (SBE 29 strain gauge pressure sensor); Analyzing instrument: SeaTerm and SBE Data Processing; Detailed sampling and analyzing information: Profile measurements are continually taken at a frequency of 8 hertz. Profiles are subject to the depth of the sampled site. Hexadecimal raw data is downloaded from the CTD using the Seaterm software and converted to comma separated values format with SBE Data Processing.; Quality flag convention: 1-Not Analyzed; 2-Good; 3-Questionable, 4-Bad; 5-Not reported; 6-Duplicate. Samples values that are not reported appear as -999 with the corresponding flag number 5.; Researcher name: Julio Morell; Researcher institution: University of Puerto Rico at Mayaguez Parameter or Variable: Depth (in meters) at which sample is taken; Abbreviation: DEPTH_METER; Unit: meter; Observation type: Profile; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: measured; Calculation method and parameters: none; Sampling instrument: SBE25 CTD (SBE 29 strain gauge pressure sensor); Analyzing instrument: SeaTerm and SBE Data Processing; Detailed sampling and analyzing information: Profile measurements are continually taken at a frequency of 8 hertz. Profiles are subject to the depth of the sampled site. Hexadecimal raw data is downloaded from the CTD using the Seaterm software and converted to comma separated values format with SBE Data Processing.; Researcher name: Julio Morell; Researcher institution: University of Puerto Rico at Mayaguez Parameter or Variable: Bottom water depth of the sampling station; Abbreviation: DEPTH_BTM_METER; Unit: meter; Uncertainty: none; Researcher name: Julio Morell; Researcher institution: University of Puerto Rico at Mayaguez Parameter or Variable: In-situ temperature recorded from CTD with the scale of ITS-90; Abbreviation: CTDTMP_ITS90_DEG_C; Unit: degree Celsius; Observation type: Profile; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: Measured; Calculation method and parameters: none; Sampling instrument: SBE25 CTD (SBE 3F temperature sensor); Analyzing instrument: SeaTerm and SBE Data Processing; Detailed sampling and analyzing information: Profile measurements are continually taken at a frequency of 8 hertz. Profiles are subject to the depth of the sampled site. Hexadecimal raw data is downloaded from the CTD using the Seaterm software and converted to comma separated values format with SBE Data Processing.; Quality flag convention: 1-Not Analyzed; 2-Good; 3-Questionable, 4-Bad; 5-Not reported; 6-Duplicate. Samples values that are not reported appear as -999 with the corresponding flag number 5.; Researcher name: Julio Morell; Researcher institution: University of Puerto Rico at Mayaguez Parameter or Variable: Potential temperature referenced to 0 dbar pressure; Abbreviation: THETA_DEG_C; Unit: degree Celsius; Observation type: Profile; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: measured; Calculation method and parameters: none; Sampling instrument: SBE25 CTD (SBE 3F temperature sensor); Analyzing instrument: SeaTerm and SBE Data Processing; Detailed sampling and analyzing information: Profile measurements are continually taken at a frequency of 8 hertz. Profiles are subject to the depth of the sampled site. Hexadecimal raw data is downloaded from the CTD using the Seaterm software and converted to comma separated values format with SBE Data Processing.; Researcher name: Julio Morell; Researcher institution: University of Puerto Rico at Mayaguez Parameter or Variable: Salinity calculated from conductivity recorded by CTD; Abbreviation: CTDSAL_PSS78; Unit: PSU; Observation type: Profile; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: Measured; Calculation method and parameters: none; Sampling instrument: SBE25 CTD (SBE 4C conductivity sensor); Analyzing instrument: SeaTerm and SBE Data Processing; Detailed sampling and analyzing information: Profile measurements are continually taken at a frequency of 8 hertz. Profiles are subject to the depth of the sampled site. Hexadecimal raw data is downloaded from the CTD using the Seaterm software and converted to comma separated values format with SBE Data Processing.; Quality flag convention: 1-Not Analyzed; 2-Good; 3-Questionable, 4-Bad; 5-Not reported; 6-Duplicate. Samples values that are not reported appear as -999 with the corresponding flag number 5.; Researcher name: Julio Morell; Researcher institution: University of Puerto Rico at Mayaguez Parameter or Variable: Potential density anomaly referenced to 0 dbar pressure; Abbreviation: SIGMATHETA_KG_M3; Unit: kg/m^3; Observation type: Profile; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: Measured; Calculation method and parameters: none; Sampling instrument: SBE25 CTD (SBE 4C conductivity sensor); Analyzing instrument: SeaTerm and SBE Data Processing; Detailed sampling and analyzing information: Profile measurements are continually taken at a frequency of 8 hertz. Profiles are subject to the depth of the sampled site. Hexadecimal raw data is downloaded from the CTD using the Seaterm software and converted to comma separated values format with SBE Data Processing.; Uncertainty: none; Researcher name: Julio Morell; Researcher institution: University of Puerto Rico at Mayaguez Parameter or Variable: Concentration of nitrate (NO3-) measured from discrete bottles; Abbreviation: NITRATE_UMOL_KG; Unit: umol/kg; Observation type: Discrete water sample; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: measured; Calculation method and parameters: calibration curve; Sampling instrument: Van Dorn Bottle; Analyzing instrument: Shimadzu 1601 and Shimadzu 1800 spectrophotometers; Detailed sampling and analyzing information: Samples where preserved at 4degC for later analysis. Absorbance is measured at 543 nm in a double beam spectrophotometer in the UV-visible region. The concentration of nitrite is determined first. Afterwards, all the nitrate is reduced to nitrite to determine the concentration of nitrate and nitrite. Thus, the concentration of nitrate is determined by difference. A calibration curve of sodium nitrite standard solutions is considered to determine the unknown concentrations of reactive silicate in seawater solution.; Quality flag convention: 1-Not Analyzed; 2-Good; 3-Questionable, 4-Bad; 5-Not reported; 6-Duplicate. Samples values that are not reported appear as -999 with the corresponding flag number 5.; Method reference: Strickland, J.D.H and Parsons, 1972. A practical handbook of seawater analysis. Fish. Res. Bd. Canada. Bull. 1667 (2nd ed.) Ottawa. 310 pp.; Researcher name: Julio Morell; Researcher institution: University of Puerto Rico at Mayaguez Parameter or Variable: Concentration of silicate (Si(OH)4, H4SiO4, SiO2, Sil) measured from discrete bottles; Abbreviation: SILICATE_UMOL_KG; Unit: umol/kg; Observation type: Discrete water sample; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: measured; Calculation method and parameters: calibration curve; Sampling instrument: Van Dorn Bottle; Analyzing instrument: Shimadzu 1601 and Shimadzu 1800 spectrophotometers; Detailed sampling and analyzing information: Samples where preserved at 4degC for later analysis. Absorbance is measured at 810 nm in a double beam spectrophotometer in the UV-visible region. A calibration curve of sodium silicofluoride standard solutions is considered to determine the unknown concentrations of reactive silicate in seawater solution.; Quality flag convention: 1-Not Analyzed; 2-Good; 3-Questionable, 4-Bad; 5-Not reported; 6-Duplicate. Samples values that are not reported appear as -999 with the corresponding flag number 5.; Method reference: Strickland, J.D.H and Parsons, 1972. A practical handbook of seawater analysis. Fish. Res. Bd. Canada. Bull. 1667 (2nd ed.) Ottawa. 310 pp.; Researcher name: Julio Morell; Researcher institution: University of Puerto Rico at Mayaguez Parameter or Variable: Concentration of phosphate (PO4--) measured from discrete bottles; Abbreviation: PHOSPHATE_UMOL_KG; Unit: umol/kg; Observation type: Discrete; In-situ / Manipulation / Response variable: in-situ observation; Measured or calculated: Measured; Calculation method and parameters: calibration curve; Sampling instrument: Van Dorn Bottle; Analyzing instrument: Shimadzu 1601 and Shimadzu 1800 spectrophotometers; Detailed sampling and analyzing information: Samples where preserved at 4degC for later analysis. Absorbance is measured at 885 nm in a double beam spectrophotometer in the UV-visible region. A calibration curve of potassium dihydrogen phosphate standard solutions is considered to determine the unknown concentrations of reactive phosphate in seawater solution.; Quality flag convention: 1-Not Analyzed; 2-Good; 3-Questionable, 4-Bad; 5-Not reported; 6-Duplicate. Samples values that are not reported appear as -999 with the corresponding flag number 5.; Method reference: Strickland, J.D.H and Parsons, 1972. A practical handbook of seawater analysis. Fish. Res. Bd. Canada. Bull. 1667 (2nd ed.) Ottawa. 310 pp.; Researcher name: Julio Morell; Researcher institution: University of Puerto Rico at Mayaguez asNeeded Metadata are developed, maintained and distributed by NCEI. Updates are performed as needed to maintain currentness. NOAA National Centers for Environmental Information custodian CTD CTD Conductivity-Temperature-Depth probe Niskin bottle Niskin bottle Device for obtaining samples of seawater at a specific depth Why special entry for Niskin bottle but no entry for Nansen bottle? Non-dispersive infrared (NDIR) dissolved inorganic carbon (DIC) analyzer Non-dispersive infrared (NDIR) dissolved inorganic carbon (DIC) analyzer 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 with a non-dispersive infrared (NDIR) carbon dioxide analyzer. spectrophotometer spectrophotometer spectrophotometer, optical spectrometer, spectrograph or spectroscope An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. Butler, L. R. P.; Laqua, K. (1995). "Nomenclature, symbols, units and their usage in spectrochemical analysis-IX. Instrumentation for the spectral dispersion and isolation of optical radiation (IUPAC Recommendations 1995)". Pure Appl. Chem. IUPAC. 67 (10): 1725–1744. doi:10.1351/pac199567101725. A spectrometer is the general term for describing a combination of spectral apparatus with one or more detectors to measure the intensity of one or more spectral bands." thermosalinograph thermosalinograph automated sea surface temperature and salinity instrument, usually attached to the hull of a ship Thermosalinograph is an automated Sea Surface Temperature and Salinity measurement system making measurement on board a ship using a water intake. [https://www.aoml.noaa.gov/phod/tsg/about.php 2021-01-29] titrator titrator titrator