University of Tasmania
Browse

File(s) not publicly available

The subsurface layer reference to calculate preformed alkalinity and air–sea CO2 disequilibrium in the Atlantic Ocean

journal contribution
posted on 2023-05-18, 12:56 authored by Vazquez-Rodriguez, M, Padin, XA, Pardo, PC, Rios, AF, Perez, FF
The subsurface ocean layer (100–200 m deep) is suggested as a reference to parameterise preformed alkalinity (AT°) and air–sea CO2 disequilibrium (∆Cdis) in the Atlantic. Results suggest that this domain retains the memory of water mass formation (WMF) conditions over annual periods and avoids the large, short-term variability of the uppermost layers. Its thermohaline variability also encompasses and represents all water masses that outcrop in the Atlantic. Subsurface data also avoids the scarcity of late wintertime surface observations and benefit from the larger availability of year-round measurements, thus enhancing their representativeness and application coverage. This last feature is most relevant in high Atlantic latitudes, where WMF typically occurs and the widespread ice sheets often preclude surface pCO2 sampling during wintertime. The obtained AT° and ΔCdis parameterisations achieve uncertainties of ± 4.6 and ± 5.6 μmol kg− 1, respectively, improving significantly the estimates in previous works, particularly in the high latitudes. The AT° parameterisation is well correlated with observations and is coherent with the latitudinal subsurface distribution of silicate, particularly in the northern subpolar region, where previous studies showed discrepancies. The ΔCdis estimates in the upper layers are coherent with air–sea ∆pCO2 data from Takahashi's climatology, thus tackling known important shortcomings and biases of anthropogenic CO2 estimates in Atlantic waters.

History

Publication title

Journal of Marine Systems

Volume

94

Pagination

52-63

ISSN

0924-7963

Department/School

Institute for Marine and Antarctic Studies

Publisher

Elsevier Science Bv

Place of publication

Po Box 211, Amsterdam, Netherlands, 1000 Ae

Repository Status

  • Restricted

Socio-economic Objectives

Measurement and assessment of marine water quality and condition

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC