gov.noaa.nodc:0307424 eng utf8 nonGeographicDataset 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 2026-03-26T08:57:08Z ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) Data for Novel field trial for ocean alkalinity enhancement using electrochemically derived aqueous alkalinity from 2024-11-07 to 2025-02-08 (NCEI Accession 0307424) 2025-09-02 publication 2025-08-27 creation International DOI Foundation (IDF) 10.25921/7zf4-3135 NOAA National Centers for Environmental Information gov.noaa.nodc:0307424 NCEI Archive Management System 0307424 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 Allison M. Savoie Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) allison.savoie@pnnl.gov http://www.pnl.gov/ HTTP Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) website Institution web page information resourceProvider Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) http://www.pnl.gov/ HTTP Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) website Institution web page information resourceProvider Mallory Ringham Ebb Carbon, Inc mallory@ebbcarbon.com principalInvestigator Carolina Torres Sanchez Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) carolina.torressanchez@pnnl.gov http://www.pnl.gov/ HTTP Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) website Institution web page information principalInvestigator Brendan Carter Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington, under grant from NOAA Pacific Marine Environmental Laboratory brendan.carter@gmail.com principalInvestigator Sean Dougherty NOAA Pacific Marine Environmental Laboratory (PMEL) sean.dougherty@noaa.gov https://www.pmel.noaa.gov/ HTTPS NOAA Pacific Marine Environmental Laboratory (PMEL) website Institution web page information principalInvestigator Richard Feely NOAA Pacific Marine Environmental Laboratory (PMEL) Richard.A.Feely@noaa.gov https://www.pmel.noaa.gov/ HTTPS NOAA Pacific Marine Environmental Laboratory (PMEL) website Institution web page information principalInvestigator Dave Hegeman Ebb Carbon, Inc dave@ebbcarbon.com principalInvestigator Julian Herndon Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington under grant from NOAA Pacific Marine Environmental Laboratory Julian.Herndon@noaa.gov principalInvestigator Tarang Khangaonkar Pacific Northwest National Laboratory and University of Washington Salish Sea Modeling Center tarang.khangaonkar@pnnl.gov principalInvestigator Jeremy Loretz Ebb Carbon, Inc jeremy@ebbcarbon.com principalInvestigator Tyson Minck Ebb Carbon, Inc tyson@ebbcarbon.com principalInvestigator Todd Pelman Ebb Carbon, Inc tp@ebbcarbon.com principalInvestigator Lakshitha Premathilake Pacific Northwest National Laboratory and University of Washington Salish Sea Modeling Center malerajage.premathilake@pnnl.gov principalInvestigator Chinmayee Subban Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) chinmayee.subban@pnnl.gov http://www.pnl.gov/ HTTP Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) website Institution web page information principalInvestigator Jesse Vance Ebb Carbon, Inc jesse@ebbcarbon.com principalInvestigator Nicholas D. Ward Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) nicholas.ward@pnnl.gov http://www.pnl.gov/ HTTP Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) website Institution web page information principalInvestigator Savoie, Allison M. Pacific Northwest National Laboratory author Ringham, Mallory Ebb Carbon, Inc author Torres Sanchez, Carolina Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) http://www.pnl.gov/ HTTP Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) website Institution web page information author Carter, Brendan R. Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington, under grant from NOAA Pacific Marine Environmental Laboratory author Dougherty, Sean NOAA Pacific Marine Environmental Laboratory (PMEL) sean.dougherty@noaa.gov https://www.pmel.noaa.gov/ HTTPS NOAA Pacific Marine Environmental Laboratory (PMEL) website Institution web page information author Feely, Richard A. NOAA Pacific Marine Environmental Laboratory (PMEL) https://www.pmel.noaa.gov/ HTTPS NOAA Pacific Marine Environmental Laboratory (PMEL) website Institution web page information author Hegeman, Dave Ebb Carbon, Inc author Herndon, Julian Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington under grant from NOAA Pacific Marine Environmental Laboratory author Khangaonkar, Tarang Pacific Northwest National Laboratory and University of Washington Salish Sea Modeling Center author Loretz, Jeremy Ebb Carbon, Inc author Minck, Tyson Ebb Carbon, Inc author Pelman, Todd Ebb Carbon, Inc author Premathilake, Lakshitha Pacific Northwest National Laboratory and University of Washington Salish Sea Modeling Center author Subban, Chinmayee Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) http://www.pnl.gov/ HTTP Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) website Institution web page information author Vance, Jesse Ebb Carbon, Inc author Ward, Nicholas D. Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) http://www.pnl.gov/ HTTP Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) website Institution web page information author Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) http://www.pnl.gov/ HTTP Battelle Memorial Institute, Pacific Northwest National Laboratory (PNNL) website Institution web page information contributor University of Washington Cooperative Institute for Climate, Ocean and Ecosystem Studies (CICOES) https://cicoes.uw.edu/ HTTPS University of Washington Cooperative Institute for Climate, Ocean and Ecosystem Studies (CICOES) website Institution web page information contributor NOAA Pacific Marine Environmental Laboratory (PMEL) https://www.pmel.noaa.gov/ HTTPS NOAA Pacific Marine Environmental Laboratory (PMEL) website Institution web page information contributor tableDigital Ocean alkalinity enhancement is a proposed method of marine carbon dioxide removal that enhances the ocean’s uptake of atmospheric carbon dioxide (CO2) and converts it to dissolved bicarbonate for long-term ocean storage. This method of marine carbon dioxide removal has been gaining attention for its potential to durably (10,000+ years) store large amounts of CO2 (Gt+ where 1 Gt = 1 x 10^9 tons), while potentially ameliorating acidification in the vicinity of the alkalinity release. This study focuses on a novel release of electrochemically derived aqueous alkalinity into Sequim Bay, WA, through a previously established wastewater treatment plant (WWTP). This research was made possible through the collaboration of industry, academic, and federal partners, which enabled the establishment of an Ebb Carbon electrochemical mCDR system at the Pacific Northwest National Laboratory in Sequim, WA, for ocean alkalinity enhancement field trials. During these field trials, pH was measured across the WWTP system from the initial alkalinity dosing, throughout the WWTP, and at the outfall. We use the NBS scale for pH throughout this study as it is the scale used in discharge permit limits specified for WWTP and NPDES regulation and compliance monitoring. The background pHNBS of Sequim Bay seawater was between 7.5 to 7.7 for the November and February field tests. The mixing tank's pHNBS was raised to the maximum value permitted for the WWTP (9.0) and maintained across the system (±0.2) during the outfall releases. At the outfall, the elevated pH and alkalinity was quickly diluted, such that the region with a measurable signal was limited to within ~2.5 m of the discharge pipe. We were able to successfully monitor an increase in pHNBS across all four pulses of alkalinity-enhanced seawater discharge during the February 2025 field trial, with peak pHNBS values of 8.3 or 8.1, as recorded by outfall-adjacent YSI Exo 2 sonde and SAMI-pH sensors, respectively. The alkalinity-enhanced seawater did not measurably alter the surrounding waters' temperature, salinity, turbidity, or oxygen. This study provides proof-of-concept for a conservative small-scale release of electrochemically generated alkalinity-enhanced seawater from a coastal outfall. This dataset is available to the public for a wide variety of uses including scientific research and analysis. Funding Information: NOAA-OAP (Electrochemical Acid Sequestration to Ease Ocean Acidification (EASE-OA)) Funding Information: Climateworks Foundation (22-2361) Funding Information: US DOE Water Power Technologies Office Funding Information: Ebb Carbon, Inc. 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:0307424 Graphic not available. PNG 0307424 NCEI ACCESSION NUMBER 2025-08-13 publication BAROMETRIC PRESSURE CONDUCTIVITY DISSOLVED INORGANIC CARBON (DIC) partial pressure of carbon dioxide - water pH SALINITY total alkalinity turbidity WATER TEMPERATURE theme NODC DATA TYPES THESAURUS carbon dioxide (CO2) gas analyzer multi-parameter water quality sensor pH sensor salinometer temperature sensor titrator instrument NODC INSTRUMENT TYPES THESAURUS chemical laboratory experiments water chemistry theme NODC OBSERVATION TYPES THESAURUS CHARTERED VESSEL platform NODC PLATFORM NAMES THESAURUS Battelle Memorial Institute, Pacific Northwest National Laboratory NOAA Pacific Marine Environmental Laboratory University of Washington Cooperative Institute for Climate, Ocean and Ecosystem Studies dataCentre NODC COLLECTING INSTITUTION NAMES THESAURUS Battelle Memorial Institute, Pacific Northwest National Laboratory dataCentre NODC SUBMITTING INSTITUTION NAMES THESAURUS Ocean Carbon and Acidification Data System (OCADS) project NODC PROJECT NAMES THESAURUS North Pacific Ocean West Coast - US/Canada place NODC SEA AREA NAMES THESAURUS oceanography theme WMO_CategoryCode 2012-09-15 publication DOC/NOAA/OAR/PMEL > Pacific Marine Environmental Laboratory, OAR, NOAA, U.S. Department of Commerce dataCentre Global Change Master Directory (GCMD) Data Center Keywords 2026 revision 23 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 Carbon and Acidification Data System (OCADS) Project project Ocean Acidification Search Keywords Electrochemical Acid Sequestration to Ease Ocean Acidification (EASE-OA) project Research Projects EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC PRESSURE EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > ALKALINITY EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > CARBON DIOXIDE EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > INORGANIC CARBON EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > PH EARTH SCIENCE > OCEANS > OCEAN OPTICS > TURBIDITY EARTH SCIENCE > OCEANS > OCEAN TEMPERATURE > WATER TEMPERATURE EARTH SCIENCE > OCEANS > SALINITY/DENSITY > CONDUCTIVITY EARTH SCIENCE > OCEANS > SALINITY/DENSITY > SALINITY theme Global Change Master Directory (GCMD) Science Keywords 2026 revision 23 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 Field experiment theme OCADS Study Type DIC TA pCO2 pH theme Provider Variable Abbreviations CO2 ANALYZERS > CO2 ANALYZERS PH METERS > PH METERS SALINOMETERS TEMPERATURE SENSORS > TEMPERATURE SENSORS instrument Global Change Master Directory (GCMD) Instrument Keywords 2026 revision 23 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 > PACIFIC OCEAN > NORTH PACIFIC OCEAN place Global Change Master Directory (GCMD) Location Keywords 2026 revision 23 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 North Pacific Ocean Sequim Bay U.S. West Coast place Provider Geographic Names accessLevel: public otherRestrictions Cite as: Savoie, Allison M.; Ringham, Mallory; Torres Sanchez, Carolina; Carter, Brendan R.; Dougherty, Sean; Feely, Richard A.; Hegeman, Dave; Herndon, Julian; Khangaonkar, Tarang; Loretz, Jeremy; Minck, Tyson; Pelman, Todd; Premathilake, Lakshitha; Subban, Chinmayee; Vance, Jesse; Ward, Nicholas D. (2025). Data for Novel field trial for ocean alkalinity enhancement using electrochemically derived aqueous alkalinity from 2024-11-07 to 2025-02-08 (NCEI Accession 0307424). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/7zf4-3135. 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 This dataset is licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) License. SPDX License: Creative Commons Attribution 4.0 International (CC-BY-4.0) Savoie, A. M., Ringham, M., Torres Sanchez, C., Carter, B. R., Dougherty, S., Feely, R. A., Hegeman, D., Herndon, J., Khangaonkar, T., Loretz, J., Minck, T., Pelman, T., Premathilake, L., Subban, C., Vance, J., & Ward, N. D. (2025). Novel field trial for ocean alkalinity enhancement using electrochemically derived aqueous alkalinity. Frontiers in Environmental Engineering, 4. https://doi.org/10.3389/fenve.2025.1641277 2025-09-19 publication International DOI Foundation (IDF) https://doi.org/10.3389/fenve.2025.1641277 https://doi.org/10.3389/fenve.2025.1641277 HTTPS https://doi.org/10.3389/fenve.2025.1641277 related journal article information Savoie, Allison M. author Ringham, Mallory author Torres Sanchez, Carolina author Carter, Brendan R. author Dougherty, Sean author Feely, Richard A. author Hegeman, Dave author Herndon, Julian author Khangaonkar, Tarang author Loretz, Jeremy author Minck, Tyson author Pelman, Todd author Premathilake, Lakshitha author Subban, Chinmayee author Vance, Jesse author Ward, Nicholas D. author Frontiers Media SA publisher documentDigital Front. Environ. Eng. 4 ISSN 2813-5067 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 climatologyMeteorologyAtmosphere -123.045 -123.045 48.078611 48.078611 2024-11-07 2025-02-08 This data package (Submission ID: BJGACDDN4) was acquired by NCEI from the Scientific Data Integration System (SDIS) at the NOAA Pacific Marine Environmental Laboratory (PMEL) in accordance with the archival submission agreement between NCEI and PMEL. 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Originator data format 8.332 https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0307424.html HTTPS Web browser Project Metadata Navigate directly to the URL for a descriptive web page with download links. information https://doi.org/10.25921/7zf4-3135 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/307424 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/307424 HTTPS Web browser HTTPS Navigate directly to the URL for data access and direct download. download ftp://ftp-oceans.ncei.noaa.gov/nodc/archive/arc0239/0307424/ 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 0307424 v1.1 was published. 2025-09-02T15:51:35Z NCEI Accession 0307424 v1.1 publication https://www.ncei.noaa.gov/archive/accession/0307424/1.1 HTTPS NCEI Accession 0307424 v1.1 published 2025-09-02T15:51:35Z download nonGeographicDataset Parameter or Variable: Dissolved Inorganic Carbon; Abbreviation: DIC; Unit: μmol/kg; Observation type: Surface (discrete samples); In-situ / Manipulation / Response variable: IN-SITUOBSERVATION; Measured or calculated: MEASURED; Analyzing instrument: Apollo Scitech AS-C6 DIC Analyzer; Detailed sampling and analyzing information: Discrete water samples for dissolved inorganic carbon (DIC) analysis were periodically collected from beginning to end of the experiment following standard methods outlined in Dickson et al. (2007). DIC was analyzed on an Apollo SciTech Dissolved Inorganic Carbon Analyzer (Model: AS-C6L) and referenced against certified reference materials (CRMs) supplied by the Dickson laboratory at Scripps Institution of Oceanography. The precision based on the repeated measurement of CRMs during sample analysis for DIC was determined to be ±1 µmol kg-1.; Preservation method: HgCl2; Preservative volume: 100 μL of fully saturated HgCl2; Uncertainty: 1 μmol/kg; Researcher name: Nicholas Ward, Carolina Torres Sanchez, Allison Savoie; Researcher institution: Pacific Northwest National Laboratory Parameter or Variable: Total alkalinity; Abbreviation: TA; Unit: μmol/kg; Observation type: Surface (discrete samples); In-situ / Manipulation / Response variable: IN-SITUOBSERVATION; Measured or calculated: MEASURED; Analyzing instrument: Apollo Sci-Tech AS-ALK3 Total Alkalinity Titrator; Detailed sampling and analyzing information: Discrete water samples for total alkalinity (TA) analysis were periodically collected from beginning to end of the experiment following standard methods outlined in Dickson et al. (2007). TA was analyzed on an Apollo SciTech Total Alkalinity Titrator (AS-ALK3) and referenced against certified reference materials (CRMs) supplied by the Dickson laboratory at Scripps Institution of Oceanography. The precision based on the repeated measurement of CRMs during sample analysis for TA was determined to be ±1 µmol kg-1.; Preservation method: HgCl2; Preservative volume: 100 μL of fully saturated HgCl2; Uncertainty: 1 μmol/kg; Researcher name: Nicholas Ward, Carolina Torres Sanchez, Allison Savoie; Researcher institution: Pacific Northwest National Laboratory Parameter or Variable: pH; Abbreviation: pH; pH scale: NBSSCALE(NBSORNIST); Observation type: Time-series; In-situ / Manipulation / Response variable: IN-SITUOBSERVATION; Measured or calculated: MEASURED; Sampling instrument: YSI ProDSS; YSI Exo2; Seabird HydroCAT EP-V2; SAMI pH; Detailed sampling and analyzing information: YSI Pro DSS sondes were deployed to monitor seawater temperature, salinity, turbidity, dissolved oxygen (DO), and pHNBS every minute within- 1) the flow-through mixing tank; 2) GW Cell 3 ; and 3) GW Cell 2. YSI Exo 2 sondes were deployed to monitor seawater temperature, salinity, turbidity, dissolved oxygen (DO), and pHNBS every minute at two locations- 1) on a cage deployed by divers immediately in front of the WWTP outfall and 2) hanging at 2 m depth from the pier, ~70 m away from the outfall (November only) (Fig. 1 & 3). A Seabird Hydrocat EP-V2 was deployed from the pier in February instead of a YSI Exo2 sonde and collected measurements every 3 minutes on the first day and then every 10 minutes on the following days to ensure battery life for the experiment. A Sunburst SAMI-CO2 sensor was deployed at the outfall during both the November and February experiments, which collected data every hour in November and every 30 minutes in February for higher resolution (DeGrandpre et al., 1995, Lai et al., 2018). A SAMI-pH sensor was added to the outfall cage and the pier station for the February 2025 experiment and collected data every 15 minutes (Seidel et al., 2008, Lai et al., 2018). The YSI sondes were calibrated using Orion pHNBS 4.01, 7, and 10.01 buffers. The YSI Exo2 sondes deployed at the outfall were calibrated 6 days in advance of the November alkaline release and within 24 hours of deployment before the February release, while the Pro DSS sondes were calibrated the day of the alkalinity release. The YSI Exo2 sonde was calibrated in further advance in November’s field trial due to diver availability for deployment of the sensors near the outfall. It remained off underwater until it was programmed to collect data, similar to the SAMIs. All YSI sondes measured pH at ± 0.1 accuracy and ± 0.01 resolution. The Seabird Hydrocat EP-V2 was calibrated for pH immediately before deployment at the pier using 3 colorless NBS buffers (4.01, 7.0, 10.01). This sensor had an estimated accuracy of ± 0.1 and a resolution of 0.01 units. The SAMI-pH sensors were calibrated annually following manufacturer recommendations by Sunburst Sensors. The SAMI-pH sensors collected measurements at an accuracy of ± 0.003 units and precision of 0.001 (in total scale). SAMI-pH data were processed using salinity data from the sondes deployed alongside them using the QC_pH program from Sunburst Sensors. YSI sondes and Seabird Hydrocat EP-V2 sensors output pH on the NBS scale by default. SAMI-pH data is on the total scale, therefore these values were input to CO2SYS to convert them to the NBS scale for comparison with the other sensors (Sharp et al., 2020).; Standardization frequency: Prior to deployment; pH standard values: 4.01, 7.00, 10.01; Researcher name: Nicholas Ward, Carolina Torres Sanchez, Allison Savoie; Researcher institution: Pacific Northwest National Laboratory Parameter or Variable: pCO2 (fCO2) autonomous; Abbreviation: pCO2; Unit: μatm; Observation type: Time-series; In-situ / Manipulation / Response variable: IN-SITUOBSERVATION; Measured or calculated: MEASURED; Sampling instrument: SAMI-CO2; Detailed sampling and analyzing information: A Sunburst SAMI-CO2 sensor was deployed at the outfall during both the November and February experiments, which collected data every hour in November and every 30 minutes in February for higher resolution. The SAMI-CO2 sensors were calibrated annually following manufacturer recommendations by Sunburst Sensors. The SAMI-CO2 collected measurements at an estimated accuracy of ± 3 µatm and precision of 1 µatm.; Uncertainty: ±3 μatm; Researcher name: Nicholas Ward, Carolina Torres Sanchez, Allison Savoie, Mallory Ringham; Researcher institution: Pacific Northwest National Laboratory; Ebb Carbon, Inc. asNeeded Metadata are developed, maintained and distributed by NCEI. Updates are performed as needed to maintain currentness. NOAA National Centers for Environmental Information custodian carbon dioxide (CO2) gas analyzer carbon dioxide (CO2) gas analyzer measures gaseous carbon dioxide Carbon dioxide gas analyzer has often been referred to as LI-COR, because a lot of researchers choose to use products manufactured by LI-COR incorporation for their carbon dioxide measurement. The main component of a carbon dioxide analyzer is a nondispersive infrared (NDIR) spectroscopic sensors to detect CO2 in a gaseous environment by its characteristic absorption. Carbon dioxide (CO2) gas analyzer works together with carbon dioxide (CO2) equilibrator (insttypes_id 184) to measure carbon dioxide in the water. To measure water carbon dioxide, water needs to be continuously supplied to a showerhead inside an equilibrator. As the water flows through the equilibrator chamber, dissolved carbon dioxide exchanges quickly with air in the headspace. This air is then sampled by the carbon dioxide analyzer to determine the mole fraction of CO2 in water. multi-parameter water quality sensor multi-parameter water quality sensor used to measure temperature, salinity, dissolved oxygen, and other parameters Instrument used to measure temperature, salinity, dissolved oxygen, and other parameters, often used to measure water quality parameters. Can be a hand-held instrument or a sonde for unattended monitoring. Often used in coastal water monitoring stations. YSI is the preeminent brand (as of 2024). 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. salinometer salinometer generic salinometer use salinometer when the instrument type used is unclear but the data include salinity measurements temperature sensor temperature sensor A sensor used to measure temperature. titrator titrator titrator CHARTERED VESSEL CHARTERED VESSEL