Authorship：Lead author,　Last author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3847/1538-4357/ad10a2

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Abstract

The evolution and expansion of land plants brought about one of the most dramatic shifts in the history of the Earth system — the birth of modern soils — and likely stimulated massive changes in marine biogeochemistry and climate. Multiple marine extinctions characterized by widespread anoxia, including the Late Devonian mass extinction around 372 million years ago, may have been linked to terrestrial release of the nutrient phosphorus driven by newly-rooted landscapes. Here we use recently published Devonian lake records as variable inputs in an Earth system model of the coupled carbon-nitrogen-phosphorus-oxygen-sulfur biogeochemical cycles to evaluate whether recorded changes to phosphorus fluxes could sustain Devonian marine anoxia sufficient to drive mass extinction. Results show that globally scaled increases in riverine phosphorus export during the Late Devonian mass extinction could have generated widespread marine anoxia, as modeled perturbations in carbon isotope, temperature, oxygen, and carbon dioxide data are generally consistent with the geologic record. Similar results for large scale volcanism suggest the Late Devonian mass extinction was likely multifaceted with both land plants and volcanism as contributing factors.

DOI： 10.1038/s43247-023-01087-8

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Other Link： https://www.nature.com/articles/s43247-023-01087-8

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/gbi.12571

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Geophysical Union (AGU)  

Abstract

The Capitanian stage is characterized by marine anoxia possibly related to the extinction, although the global redox structure of the Capitanian ocean has not been constrained. We newly report a nitrogen isotope (δ¹⁵N) record from a paleo‐atoll limestone at the top of a mid‐Panthalassan seamount to constrain the spatial extent and duration of the Capitanian marine anoxia. The δ¹⁵N value of limestone after acid treatment is substantially high for ∼5‐Myr up to +28‰, the highest through the Phanerozoic oceans, suggesting that the nitrogen source (nitrate) was substantially enriched in ¹⁵N via denitrification within subsurface oxygen‐deficient zones (ODZs; O₂ < 5 µM). Numerical modeling of nitrogen isotope dynamics in the upwelling system along the seamount suggests that the possible minimum δ¹⁵N value of a global deep‐oceanic nitrate reservoir was ca. +9‰ in the Capitanian (∼4‰ higher than at the present). Furthermore, a redox‐dependent nitrogen isotope mass balance model constrained the global redox structure of the Capitanian superocean. Substantially reducing conditions (O₂ ≤ 20 µM) prevailed at intermediate water depths (100–1,000 m), in association with expanded ODZs with anoxic/euxinic cores along continental margins (≥ ∼0.4% of global ocean volume), while the deep‐ocean remained to be more oxidizing (O₂ ≤ 60 µM). The enhanced open‐ocean productivity associated with the low sea‐level and high nutrient flux to the ocean resulted in the global ocean deoxygenation during the cooling stage. Our model is consistent with previous geologic observations and with a possible link between the long‐term (∼5‐Myr) development of marine dysoxia and the extinction.

DOI： 10.1029/2022pa004573

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1111/gbi.12554

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1111/gbi.12554

Authorship：Lead author,　Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (other academic)  

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Copernicus GmbH  

Abstract. A new Earth system model of intermediate complexity – CANOPS-GRB v1.0 –is presented for use in quantitatively assessing the dynamics and stabilityof atmospheric and oceanic chemistry on Earth and Earth-like planets overgeologic timescales. The new release is designed to represent the coupledmajor element cycles of C, N, P, O, and S, as well as the global redoxbudget (GRB) in Earth's exogenic (ocean–atmosphere–crust) system, using aprocess-based approach. This framework provides a mechanistic model of theevolution of atmospheric and oceanic O2 levels on geologic timescalesand enables comparison with a wide variety of geological records to furtherconstrain the processes driving Earth's oxygenation. A complete detaileddescription of the resulting Earth system model and its new features areprovided. The performance of CANOPS-GRB is then evaluated by comparing asteady-state simulation under present-day conditions with a comprehensiveset of oceanic data and existing global estimates of bio-element cycling.The dynamic response of the model is also examined by varying phosphorusavailability in the exogenic system. CANOPS-GRB reliably simulates theshort- and long-term evolution of the coupled C–N–P–O2–S biogeochemicalcycles and is generally applicable across most period of Earth's historygiven suitable modifications to boundary conditions and forcing regime. Thesimple and adaptable design of the model also makes it useful to interrogatea wide range of problems related to Earth's oxygenation history andEarth-like exoplanets more broadly. The model source code is available onGitHub and represents a unique community tool for investigating thedynamics and stability of atmospheric and oceanic chemistry on longtimescales.

DOI： 10.5194/gmd-15-7593-2022

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Geophysical Union (AGU)  

DOI： 10.1029/2021gb007052

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Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1029/2021GB007052

Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1038/s41561-021-00693-5

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Other Link： http://www.nature.com/articles/s41561-021-00693-5

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)  

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Authorship：Lead author  

DOI： 10.1038/s41467-019-10872-z

Web of Science

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Physics Publishing  

DOI： 10.3847/1538-4357/ab05e1

Scopus

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY  

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1038/s41561-017-0031-2

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Scopus

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1038/ncomms15532

Web of Science

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Language：English   Publishing type：Research paper (scientific journal)  

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1038/NGEO2707

Web of Science

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Language：Japanese   Publisher：GEOCHEMICAL SOCIETY OF JAPAN  

DOI： 10.14862/geochemproc.61.0_65

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.epsl.2013.04.029

Web of Science

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2517/1342-8144-15.2.089

Web of Science

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.epsl.2011.02.011

Scopus

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Authorship：Lead author,　Corresponding author   Language：English  

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Publisher：GEOCHEMICAL SOCIETY OF JAPAN  

DOI： 10.14862/geochemproc.58.0.18.0

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Language：English   Presentation type：Oral presentation (invited, special)  

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Language：Japanese   Presentation type：Symposium, workshop panel (nominated)  

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Presentation type：Oral presentation (invited, special)  

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Language：English   Presentation type：Symposium, workshop panel (nominated)  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：仙台（東北大学 青葉山キャンパス）  

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：那覇（琉球大学）  

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Language：English   Presentation type：Oral presentation (invited, special)  

Venue：海浜幕張  

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