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dc.contributor.authorRothman, Daniel H.
dc.date.accessioned2020-03-31T14:19:19Z
dc.date.available2020-03-31T14:19:19Z
dc.date.issued2019-07-08
dc.identifier.issn0027-8424
dc.identifier.issn1091-6490
dc.identifier.urihttps://hdl.handle.net/1721.1/124448
dc.description.abstractThe history of the carbon cycle is punctuated by enigmatic transient changes in the ocean’s store of carbon. Mass extinction is always accompanied by such a disruption, but most disruptions are relatively benign. The less calamitous group exhibits a characteristic rate of change whereas greater surges accompany mass extinctions. To better understand these observations, I formulate and analyze a mathematical model that suggests that disruptions are initiated by perturbation of a permanently stable steady state beyond a threshold. The ensuing excitation exhibits the characteristic surge of real disruptions. In this view, the magnitude and timescale of the disruption are properties of the carbon cycle itself rather than its perturbation. Surges associated with mass extinction, however, require additional inputs from external sources such as massive volcanism. Surges are excited when CO2 enters the oceans at a flux that exceeds a threshold. The threshold depends on the duration of the injection. For injections lasting a time ti & 10, 000 y in the modern carbon cycle, the threshold flux is constant; for smaller ti, the threshold scales like ti−1. Consequently the unusually strong but geologically brief duration of modern anthropogenic oceanic CO2 uptake is roughly equivalent, in terms of its potential to excite a major disruption, to relatively weak but longer-lived perturbations associated with massive volcanism in the geologic past.en_US
dc.description.sponsorshipUnited States. National Aeronautics and Space Administration (Astrobiology Grant NNA13AA90A)en_US
dc.description.sponsorshipNational Science Foundation (U.S.) (Grant EAR-1338810)en_US
dc.language.isoen
dc.publisherProceedings of the National Academy of Sciencesen_US
dc.relation.isversionof10.1073/pnas.1905164116en_US
dc.rightsArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.en_US
dc.sourcePNASen_US
dc.subjectMultidisciplinaryen_US
dc.titleCharacteristic disruptions of an excitable carbon cycleen_US
dc.typeArticleen_US
dc.identifier.citationRothman, Daniel H. "Characteristic disruptions of an excitable carbon cycle." Proceedings of the National Academy of Sciences of the United States of America 116 (2019): 14813-14822 © 2019 The Authoren_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciencesen_US
dc.relation.journalProceedings of the National Academy of Sciences of the United States of Americaen_US
dc.eprint.versionFinal published versionen_US
dc.type.urihttp://purl.org/eprint/type/JournalArticleen_US
eprint.statushttp://purl.org/eprint/status/PeerRevieweden_US
dc.date.updated2020-02-11T13:52:44Z
dspace.date.submission2020-02-11T13:52:46Z
mit.journal.volume116en_US
mit.journal.issue30en_US
mit.licensePUBLISHER_POLICY
mit.metadata.statusComplete


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