{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,25]],"date-time":"2026-02-25T18:22:44Z","timestamp":1772043764449,"version":"3.50.1"},"reference-count":37,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,6,4]],"date-time":"2025-06-04T00:00:00Z","timestamp":1748995200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"UNC Wilmington\u2019s Department of Earth and Ocean Sciences, the College of Arts and Sciences, the Center for Marine Science, and the Office of Innovation and Commercialization via a Blue Economy Grant","award":["NA22OAR0210490"],"award-info":[{"award-number":["NA22OAR0210490"]}]},{"DOI":"10.13039\/100000192","name":"Sunburst Sensors","doi-asserted-by":"publisher","award":["NA22OAR0210490"],"award-info":[{"award-number":["NA22OAR0210490"]}],"id":[{"id":"10.13039\/100000192","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The ocean is one of the world\u2019s largest anthropogenic carbon dioxide (CO2) sinks, but closing the carbon budget is logistically difficult and expensive, and uncertainties in carbon fluxes and reservoirs remain. One specific challenge is that measuring the CO2 flux at the air\u2013sea interface usually requires costly sensors or analyzers (USD &gt; 30,000), which can limit observational capacity. Our group has developed and validated a low-cost \u0394pCO2 system, able to measure both pCO2water and pCO2air, for USD ~1400 to combat this limitation. The device is equipped with Internet of Things (IoT) capabilities and built around a USD ~100 pCO2 K30 sensor at its core. Our Sensor for the Exchange of Atmospheric CO2 with Water (SEACOW) may be placed in an observational network with traditional pCO2 sensors or \u2206pCO2 sensors to extend the spatial coverage and resolution of monitoring systems. After calibration, the SEACOW reports atmospheric pCO2 measurements that are within 2\u20133% of the measurements made with a calibrated LI-COR LI-850. We also demonstrate the SEACOW\u2019s ability to capture diel pCO2 cycling in seagrass, provide recommendations for SEACOW field deployments, and provide additional technical specifications for the SEACOW and for the K30 itself (e.g., air- and water-side 99.3% response time; 5.7 and 29.6 min, respectively).<\/jats:p>","DOI":"10.3390\/s25113547","type":"journal-article","created":{"date-parts":[[2025,6,4]],"date-time":"2025-06-04T11:14:12Z","timestamp":1749035652000},"page":"3547","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Developing a Low-Cost Device for Estimating Air\u2013Water \u0394pCO2 in Coastal Environments"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0009-0008-2809-0614","authenticated-orcid":false,"given":"Elizabeth B.","family":"Farquhar","sequence":"first","affiliation":[{"name":"Department of Earth and Ocean Sciences, University of North Carolina Wilmington, Wilmington, NC 28403, USA"},{"name":"Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28409, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9432-752X","authenticated-orcid":false,"given":"Philip J.","family":"Bresnahan","sequence":"additional","affiliation":[{"name":"Department of Earth and Ocean Sciences, University of North Carolina Wilmington, Wilmington, NC 28403, USA"},{"name":"Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28409, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michael","family":"Tydings","sequence":"additional","affiliation":[{"name":"Department of Earth and Ocean Sciences, University of North Carolina Wilmington, Wilmington, NC 28403, USA"},{"name":"Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28409, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jessie C.","family":"Jarvis","sequence":"additional","affiliation":[{"name":"Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28409, USA"},{"name":"Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC 28403, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Robert F.","family":"Whitehead","sequence":"additional","affiliation":[{"name":"Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28409, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dan","family":"Portelli","sequence":"additional","affiliation":[{"name":"Department of Earth and Ocean Sciences, University of North Carolina Wilmington, Wilmington, NC 28403, USA"},{"name":"Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC 28409, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,4]]},"reference":[{"key":"ref_1","first-page":"1","article-title":"Global carbon budget 2024","volume":"2024","author":"Friedlingstein","year":"2024","journal-title":"Earth Syst. 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