Marine Science Faculty Publications

Document Type

Article

Publication Date

2023

Digital Object Identifier (DOI)

https://doi.org/10.5281/zenodo.10115891

Abstract

Changes in the vertical structure of pH (total proton scale at 25 °C or pHT), total alkalinity, total CO2 (TCO2), and partial pressure of CO2 (pCO2) were examined at the CARIACO Ocean Time Series station (10º30'N, 64º40'W) from December 1995 to January 2017. Long-term trends were studied in the three water masses present in the Cariaco Basin: the surface layer (SL, located between 0-100 m depth), the Subtropical Underwater (SUW, with minimum depths between the surface and 105 m and maximums between 30-165 m depending on the season) and the deep water (DW, with minimum depths between 175-380 m to the bottom). The seasonal detrended TCO2 normalized to a constant salinity (nTCO2) showed a positive trend 2.23 ± 0.43 µmol kg-1 yr-1 in the SL, associated with an increase in pCO2 (3.06 ± 0.42 µatm yr-1) and a decrease in pH (-0.0028 ± 0.0004 pH yr-1). SUW and DW also exhibited increasing trends nTCO2 (1.82 ± 0.42 and 4.46 ± 0.32 µmol kg-1 yr-1, respectively). Between 2002 and 2017, an increase of 67 µmol kg-1 of TCO2 was observed below 300 m at the CARIACO station. Overall, acidification trends were observed at the Cariaco station from the surface to the bottom, with an average of ~ -0.003 ± 0.0004 pH units per year. Air-sea CO2 flux calculations showed an average net evasion of CO2 from the sea to the air of 0.6 ± 2.2 mol C m-2 yr-1 for the period of observation.

Rights Information

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Memoria de la Fundación La Salle de Ciencias Naturales, v. 81, issue 191, p. 91-110

Download

Included in

Life Sciences Commons

Share

COinS