Abstract
More than 74 biogeochemical profiling floats that measure water column pH, oxygen, nitrate, fluorescence, and backscattering at 10 day intervals have been deployed throughout the Southern Ocean. Calculating the surface ocean partial pressure of carbon dioxide (pCO2sw) from float pH has uncertainty contributions from the pH sensor, the alkalinity estimate, and carbonate system equilibrium constants, resulting in a relative standard uncertainty in pCO2sw of 2.7% (or 11 µatm at pCO2sw of 400 µatm). The calculated pCO2sw from several floats spanning a range of oceanographic regimes are compared to existing climatologies. In some locations, such as the subantarctic zone, the float data closely match the climatologies, but in the polar Antarctic zone significantly higher pCO2sw are calculated in the wintertime implying a greater air-sea CO2 efflux estimate. Our results based on four representative floats suggest that despite their uncertainty relative to direct measurements, the float data can be used to improve estimates for air-sea carbon flux, as well as to increase knowledge of spatial, seasonal, and interannual variability in this flux.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 591-604 |
| Number of pages | 14 |
| Journal | Global Biogeochemical Cycles |
| Volume | 31 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 1 2017 |
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Keywords
- air-sea carbon dioxide flux
- biogeochemical floats
- carbon budget
- pH sensor
- Southern Ocean
ASJC Scopus subject areas
- Global and Planetary Change
- Environmental Chemistry
- Environmental Science(all)
- Atmospheric Science
Cite this
Calculating surface ocean pCO2 from biogeochemical Argo floats equipped with pH : An uncertainty analysis. / Williams, N. L.; Juranek, L. W.; Feely, R. A.; Johnson, K. S.; Sarmiento, J. L.; Talley, L. D.; Dickson, A. G.; Gray, A. R.; Wanninkhof, R.; Russell, Joellen; Riser, S. C.; Takeshita, Y.
In: Global Biogeochemical Cycles, Vol. 31, No. 3, 01.03.2017, p. 591-604.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Calculating surface ocean pCO2 from biogeochemical Argo floats equipped with pH
T2 - An uncertainty analysis
AU - Williams, N. L.
AU - Juranek, L. W.
AU - Feely, R. A.
AU - Johnson, K. S.
AU - Sarmiento, J. L.
AU - Talley, L. D.
AU - Dickson, A. G.
AU - Gray, A. R.
AU - Wanninkhof, R.
AU - Russell, Joellen
AU - Riser, S. C.
AU - Takeshita, Y.
PY - 2017/3/1
Y1 - 2017/3/1
N2 - More than 74 biogeochemical profiling floats that measure water column pH, oxygen, nitrate, fluorescence, and backscattering at 10 day intervals have been deployed throughout the Southern Ocean. Calculating the surface ocean partial pressure of carbon dioxide (pCO2sw) from float pH has uncertainty contributions from the pH sensor, the alkalinity estimate, and carbonate system equilibrium constants, resulting in a relative standard uncertainty in pCO2sw of 2.7% (or 11 µatm at pCO2sw of 400 µatm). The calculated pCO2sw from several floats spanning a range of oceanographic regimes are compared to existing climatologies. In some locations, such as the subantarctic zone, the float data closely match the climatologies, but in the polar Antarctic zone significantly higher pCO2sw are calculated in the wintertime implying a greater air-sea CO2 efflux estimate. Our results based on four representative floats suggest that despite their uncertainty relative to direct measurements, the float data can be used to improve estimates for air-sea carbon flux, as well as to increase knowledge of spatial, seasonal, and interannual variability in this flux.
AB - More than 74 biogeochemical profiling floats that measure water column pH, oxygen, nitrate, fluorescence, and backscattering at 10 day intervals have been deployed throughout the Southern Ocean. Calculating the surface ocean partial pressure of carbon dioxide (pCO2sw) from float pH has uncertainty contributions from the pH sensor, the alkalinity estimate, and carbonate system equilibrium constants, resulting in a relative standard uncertainty in pCO2sw of 2.7% (or 11 µatm at pCO2sw of 400 µatm). The calculated pCO2sw from several floats spanning a range of oceanographic regimes are compared to existing climatologies. In some locations, such as the subantarctic zone, the float data closely match the climatologies, but in the polar Antarctic zone significantly higher pCO2sw are calculated in the wintertime implying a greater air-sea CO2 efflux estimate. Our results based on four representative floats suggest that despite their uncertainty relative to direct measurements, the float data can be used to improve estimates for air-sea carbon flux, as well as to increase knowledge of spatial, seasonal, and interannual variability in this flux.
KW - air-sea carbon dioxide flux
KW - biogeochemical floats
KW - carbon budget
KW - pH sensor
KW - Southern Ocean
UR - http://www.scopus.com/inward/record.url?scp=85017338740&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85017338740&partnerID=8YFLogxK
U2 - 10.1002/2016GB005541
DO - 10.1002/2016GB005541
M3 - Article
AN - SCOPUS:85017338740
VL - 31
SP - 591
EP - 604
JO - Global Biogeochemical Cycles
JF - Global Biogeochemical Cycles
SN - 0886-6236
IS - 3
ER -