Spatial and Temporal Variability of pCO₂, Carbon Fluxes, and Saturation State on the West Florida Shelf

Authors

Lisa L. Robbins, University of South FloridaFollow
Kendra L. Daly, University of South FloridaFollow
L. Barbero, University of Miami
R. Wanninkhof, NOAA's Atlantic Oceanographic and Meteorological Laboratory
R. He, North Carolina State University at Raleigh
H. Zong, North Carolina State University at Raleigh
J. T. Lisle, U.S. Geological Survey
W. J. Cai, University of Delaware
C. G. Smith, U.S. Geological Survey

Document Type

Article

Publication Date

9-2018

Keywords

West Florida Shelf, Gulf of Mexico, pCO2, carbon flux, saturation state, carbon budget

Digital Object Identifier (DOI)

https://doi.org/10.1029/2018JC014195

Abstract

The West Florida Shelf (WFS) is a source of uncertainty for the Gulf of Mexico carbon budget. Data from the synthesis of approximately 135,000 pCO₂ values from 97 cruises from the WFS show that the shelf waters fluctuate between being a weak source to a weak sink of carbon. Overall, the shelf acts as a weak source of CO₂ at 0.32 ± 1.5 mol m⁻² yr⁻¹. Subregions, however, reveal slightly different trends, where surface waters associated with 40–200‐m isobath in the northern and southern WFS are generally weak sinks all year, except for summer when they act as sources of CO₂. Conversely, nearshore waters (<40 m) are a source of CO₂, particularly the southern shallow waters, which are a source all year round. The pCO₂ of seawater has been increasing at a rate of approximately 4.37 μatm/year as compared to atmospheric pCO₂ which has increased at a rate of about 1.7 μatm per year from 1996 to 2016. The annual CO₂ flux has increased from −0.78 to 0.92 mol m⁻² yr⁻¹ on the shelf from 1996–2016. The WFS is emitting 9.23 Tg C/year, with the southern nearshore region emitting the most at 9.01 Tg C/year and the northern region acting as a sink of −1.96 Tg C/year. Aragonite saturation state on the WFS shows seasonal and geographic trends with values ranging from 2 to 5. Lowest values are found in winter associated with subregion <40‐m isobath.

Rights Information

This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Journal of Geophysical Research: Oceans, v. 123, issue 9, p. 6174-6188

Scholar Commons Citation

Robbins, Lisa L.; Daly, Kendra L.; Barbero, L.; Wanninkhof, R.; He, R.; Zong, H.; Lisle, J. T.; Cai, W. J.; and Smith, C. G., "Spatial and Temporal Variability of pCO₂, Carbon Fluxes, and Saturation State on the West Florida Shelf" (2018). Marine Science Faculty Publications. 884.
https://digitalcommons.usf.edu/msc_facpub/884