Global Groundwater Carbon Mass Flux and the Myth of Atmospheric Weathering
© 2024 The Author(s). Groundwater published by Wiley Periodicals LLC on behalf of National Ground Water Association. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.
| Veröffentlicht in: | Ground water. - 1979. - 63(2025), 1 vom: 19. Jan., Seite 14-24 |
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| Weitere Verfasser: | , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2025
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| Zugriff auf das übergeordnete Werk: | Ground water |
| Schlagworte: | Journal Article Carbon Dioxide 142M471B3J Carbon 7440-44-0 |
| Zusammenfassung: | © 2024 The Author(s). Groundwater published by Wiley Periodicals LLC on behalf of National Ground Water Association. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA. Our recent steady-state mass-balance modeling suggests that most global carbonic-acid weathering of silicate rocks occurs in the vadose zone of aquifer systems not on the surface by atmospheric CO2. That is, the weathering solute flux is nearly equal to the total global continental riverine carbon flux, signifying little atmospheric weathering by carbonic acid. This finding challenges previous carbon models that utilize silicate weathering as a control of atmospheric CO2 levels. A robust analysis utilizing global estimates of groundwater carbon concentration generated by a geospatial machine learning algorithm was coupled with recharge flux in a geographic information system environment to yield a total global groundwater carbon flux of between 0.87 and 0.96 Pg C/year to the surface environment. On discharging to the surface, the carbon is speciated between 0.01 and 0.11 Pg C/year as CaCO3; 0.35 and 0.38 Pg C/year as CO2 gas; and 0.49 and 0.51 Pg C/year as dissolved HCO3 -. This total weathering carbon flux was calculated for direct ocean discharge (0.030 Pg C/year); endorheic basins (0.046 Pg C/year); cold-wet exorheic basins (0.058 Pg C/year); warm-dry exorheic basins (0.072 Pg C/year); cold-dry exorheic basins (0.115 Pg C/year); and warm-wet exorheic basins (0.448 Pg C/year) |
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| Beschreibung: | Date Completed 03.01.2025 Date Revised 05.01.2025 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1745-6584 |
| DOI: | 10.1111/gwat.13457 |