TY - JOUR
T1 - Oxygen in the Southern Ocean From Argo Floats
T2 - Determination of Processes Driving Air-Sea Fluxes
AU - Bushinsky, Seth M.
AU - Gray, Alison R.
AU - Johnson, Kenneth S.
AU - Sarmiento, Jorge Louis
N1 - Funding Information:
SOCCOM float data were collected and made freely available by the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) Project funded by National Science Foundation, Division of Polar Programs (NSF PLR -1425989), supplemented by NOAA and NASA (PI Jorge Sarmiento). We would like to thank R. Drucker and S. Riser for providing the University of Washington Argo data set (v1.1, supported from NOAA grant NA15OAR4320063 to the University of Washington). We would also like to thank the many people at the Monterey Bay Aquarium Research Institute and the University of Washington who quality controlled and corrected the SOCCOM float data. SOCCOM data used in this analysis can be found in a data snapshot taken on 6 June 2017 (http://soccompu. princeton.edu/www/index.html, https://doi.org/10.6075/J0348H8K). NOAA High-Resolution SST data provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA, from their Web site at http://www.esrl.noaa.gov/ psd/. We would like to thank the Argo program, without which none of this research is possible. Argo temperature and salinity for the floats in this study are available at http://www.seanoe. org/data/00311/42182/ (Argo, 2000). SOCCOM cruise data and deployment information available at: https:// soccom.princeton.edu/content/shipboard-data-reports. We thank J. Plant for SOCCOMviz ingestion scripts. Rick Slater provided CM2.6 monthly output and subsampled daily model oxygen fluxes at float locations. We would especially like to thank the numerous scientists and ship’s crews involved in the deployment, collection, and quality control of the data used in this study. Finally, we would like to thank Nicolas Gruber and an anonymous reviewer for their helpful comments that greatly improved this manuscript.
Publisher Copyright:
© 2017. American Geophysical Union. All Rights Reserved.
PY - 2017/11
Y1 - 2017/11
N2 - The Southern Ocean is of outsized significance to the global oxygen and carbon cycles with relatively poor measurement coverage due to harsh winters and seasonal ice cover. In this study, we use recent advances in the parameterization of air-sea oxygen fluxes to analyze 9 years of oxygen data from a recalibrated Argo oxygen data set and from air-calibrated oxygen floats deployed as part of the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project. From this combined data set of 150 floats, we find a total Southern Ocean oxygen sink of −183 ± 80 Tmol yr−1 (positive to the atmosphere), greater than prior estimates. The uptake occurs primarily in the Polar-Frontal Antarctic Zone (PAZ, −94 ± 30 Tmol O2 yr−1) and Seasonal Ice Zone (SIZ, −111 ± 9.3 Tmol O2 yr−1). This flux is driven by wintertime ventilation, with a large portion of the flux in the SIZ passing through regions with fractional sea ice. The Subtropical Zone (STZ) is seasonally driven by thermal fluxes and exhibits a net outgassing of 47 ± 29 Tmol O2 yr−1 that is likely driven by biological production. The Subantarctic Zone (SAZ) uptake is −25 ± 12 Tmol O2 yr−1. Total oxygen fluxes were separated into a thermal and nonthermal component. The nonthermal flux is correlated with net primary production and mixed layer depth in the STZ, SAZ, and PAZ, but not in the SIZ where seasonal sea ice slows the air-sea gas flux response to the entrainment of deep, low-oxygen waters.
AB - The Southern Ocean is of outsized significance to the global oxygen and carbon cycles with relatively poor measurement coverage due to harsh winters and seasonal ice cover. In this study, we use recent advances in the parameterization of air-sea oxygen fluxes to analyze 9 years of oxygen data from a recalibrated Argo oxygen data set and from air-calibrated oxygen floats deployed as part of the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project. From this combined data set of 150 floats, we find a total Southern Ocean oxygen sink of −183 ± 80 Tmol yr−1 (positive to the atmosphere), greater than prior estimates. The uptake occurs primarily in the Polar-Frontal Antarctic Zone (PAZ, −94 ± 30 Tmol O2 yr−1) and Seasonal Ice Zone (SIZ, −111 ± 9.3 Tmol O2 yr−1). This flux is driven by wintertime ventilation, with a large portion of the flux in the SIZ passing through regions with fractional sea ice. The Subtropical Zone (STZ) is seasonally driven by thermal fluxes and exhibits a net outgassing of 47 ± 29 Tmol O2 yr−1 that is likely driven by biological production. The Subantarctic Zone (SAZ) uptake is −25 ± 12 Tmol O2 yr−1. Total oxygen fluxes were separated into a thermal and nonthermal component. The nonthermal flux is correlated with net primary production and mixed layer depth in the STZ, SAZ, and PAZ, but not in the SIZ where seasonal sea ice slows the air-sea gas flux response to the entrainment of deep, low-oxygen waters.
KW - Argo profiling floats
KW - Southern Ocean seasonal cycles
KW - air-sea oxygen fluxes
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U2 - 10.1002/2017JC012923
DO - 10.1002/2017JC012923
M3 - Article
AN - SCOPUS:85033572382
SN - 2169-9291
VL - 122
SP - 8661
EP - 8682
JO - Journal of Geophysical Research: Oceans
JF - Journal of Geophysical Research: Oceans
IS - 11
ER -