Cristin-resultat-ID: 1977524
Sist endret: 3. februar 2022, 15:37
NVI-rapporteringsår: 2021
Resultat
Vitenskapelig artikkel
2021

New paleogeographic and degassing parameters for long-term carbon cycle models

Bidragsytere:
  • Chloe M. Marcilly
  • Trond Helge Torsvik
  • Mathew Michael Domeier og
  • Dana L. Royer

Tidsskrift

Gondwana Research
ISSN 1342-937X
e-ISSN 1878-0571
NVI-nivå 1

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2021
Publisert online: 2021
Trykket: 2021
Volum: 97
Sider: 176 - 203
Open Access

Importkilder

Scopus-ID: 2-s2.0-85107687417

Beskrivelse Beskrivelse

Tittel

New paleogeographic and degassing parameters for long-term carbon cycle models

Sammendrag

Long-term carbon cycle models are critical for understanding the levels and underlying controls of atmospheric CO2 over geological time-scales. We have refined the implementation of two important boundary conditions in carbon cycle models, namely consumption by silicate weathering and carbon degassing. Through the construction of continental flooding maps for the past 520 million years (Myrs), we have estimated exposed land area relative to the present-day (fA), and the fraction of exposed land area undergoing silicate weathering (fAW-fA). The latter is based on the amount of exposed land within the tropics (±10°) plus the northern/southern wet belts (40-50°N/S) relative to today, which are the prime regions for silicate weathering. We also evaluated climate gradients and potential weatherability by examining the distribution of climate-sensitive indicators. This is particularly important during and after Pangea formation, when we reduce fAW-fA during times when arid equatorial regions were present. We also estimated carbon degassing for the past 410 Myrs using subduction flux from full-plate models as a proxy. We then, for the first time, used the subduction flux to scale and normalize the arc-related zircon age distribution (arc-activity), which allows us to estimate carbon degassing in much deeper time. The effect of these refined modelling parameters for weathering and degassing was then tested in the GEOCARBSULF model, and the results are compared to other climate models and CO2 proxies. The use of arc-activity as a proxy for carbon degassing brings Mesozoic model estimates closer to CO2 proxy values but our models are highly sensitive to the definition of fAW-fA. Considering the land availability to weathering to only variations in tropical latitudes (corrected for arid regions) combined with our new degassing estimates leads to notably higher CO2 levels in the Mesozoic and a better fit with the CO2 proxies.

Bidragsytere

Chloé Franca Margot Marcilly

Bidragsyterens navn vises på dette resultatet som Chloe M. Marcilly
  • Tilknyttet:
    Forfatter
    ved Senter for Jordens utvikling og dynamikk ved Universitetet i Oslo

Trond Helge Torsvik

  • Tilknyttet:
    Forfatter
    ved University of the Witwatersrand, Johannesburg
  • Tilknyttet:
    Forfatter
    ved Senter for Jordens utvikling og dynamikk ved Universitetet i Oslo

Mathew Michael Domeier

  • Tilknyttet:
    Forfatter
    ved Senter for Jordens utvikling og dynamikk ved Universitetet i Oslo

Dana L. Royer

  • Tilknyttet:
    Forfatter
    ved Wesleyan University
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