The effects of bathymetry on the long-term carbon cycle and CCD DOI Creative Commons
Matthew Bogumil, Tushar Mittal, Carolina Lithgow‐Bertelloni

et al.

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(21)

Published: May 15, 2024

The shape of the ocean floor (bathymetry) and overlaying sediments provide largest carbon sink throughout Earth’s history, supporting ~one to two orders magnitude more storage than oceans atmosphere combined. While accumulation erosion these are bathymetry dependent (e.g., due pressure, temperature, salinity, ion concentration, available productivity), no systemic study has quantified how global basin scale bathymetry, controlled by evolution tectonics mantle convection, affects long-term cycle. We reconstruct spanning last 80 Myr describe steady-state changes in chemistry within Earth system model LOSCAR. find that both reconstructions representative synthetic tests show alkalinity, calcite saturation state, carbonate compensation depth (CCD) strongly on shallow (ocean ≤600 m) distribution deep marine regions (>1,000 m). Limiting Cenozoic alone leads predicted CCD variations 500 m, 33 50% total observed paleoproxy records. Our results suggest neglecting bathymetric significant misattribution uncertain cycle parameters atmospheric CO 2 water column temperature) processes biological pump efficiency silicate-carbonate riverine flux). To illustrate this point, we use our updated for an Early Paleogene C case study. obtain flux estimates a reversal weathering trend with respect present-day, contrasting previous studies, but consistent proxy records tectonic reconstructions.

Language: Английский

Large Igneous Province Sulfur Emissions Have Long‐Term (>1000 Years) Effects on the Ocean Carbon Cycle DOI Creative Commons
Hee Jun Cheong, Tushar Mittal, Courtney J. Sprain

et al.

Geochemistry Geophysics Geosystems, Journal Year: 2025, Volume and Issue: 26(3)

Published: March 1, 2025

Abstract Large Igneous Province (LIP) eruptions are thought to have driven environmental and climate change over wide temporal scales ranging from a few thousands of years. Since the radiative effects atmospheric lifetime carbon dioxide (CO 2 , warming) sulfur (SO cooling) very different, conventional assumption has been analyze CO SO emissions separately add them together afterward. In this study, we test by analyzing joint effect on marine carbonate cycle using biogeochemical box model (Long‐term Ocean‐atmosphere‐Sediment CArbon Reservoir Model). By performing runs with fine resolution (∼0.1‐year timestep), LIP gas timescales an individual eruption (hundreds years) entire long‐term (>100,000 years). We find that, contrary previous work, significant (>1,000 (dissolved inorganic carbon, pH, alkalinity, compensation depth). This is due two processes: strongly temperature‐dependent equilibrium coefficients for chemistry thousand‐year timescale ocean overturning circulation. Thus, volcanic not simply additive impact emissions. develop causal mechanistic framework visualize feedbacks associated combined timescales. Our results provide new perspective understanding complex feedback mechanisms controlling large Earth history.

Language: Английский

Citations

0
The effects of bathymetry on the long-term carbon cycle and CCD DOI Creative Commons
Matthew Bogumil, Tushar Mittal, Carolina Lithgow‐Bertelloni

et al.

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(21)

Published: May 15, 2024

The shape of the ocean floor (bathymetry) and overlaying sediments provide largest carbon sink throughout Earth’s history, supporting ~one to two orders magnitude more storage than oceans atmosphere combined. While accumulation erosion these are bathymetry dependent (e.g., due pressure, temperature, salinity, ion concentration, available productivity), no systemic study has quantified how global basin scale bathymetry, controlled by evolution tectonics mantle convection, affects long-term cycle. We reconstruct spanning last 80 Myr describe steady-state changes in chemistry within Earth system model LOSCAR. find that both reconstructions representative synthetic tests show alkalinity, calcite saturation state, carbonate compensation depth (CCD) strongly on shallow (ocean ≤600 m) distribution deep marine regions (>1,000 m). Limiting Cenozoic alone leads predicted CCD variations 500 m, 33 50% total observed paleoproxy records. Our results suggest neglecting bathymetric significant misattribution uncertain cycle parameters atmospheric CO 2 water column temperature) processes biological pump efficiency silicate-carbonate riverine flux). To illustrate this point, we use our updated for an Early Paleogene C case study. obtain flux estimates a reversal weathering trend with respect present-day, contrasting previous studies, but consistent proxy records tectonic reconstructions.

Language: Английский

Citations

2