Skip to Main content Skip to Navigation
Theses

Variations de la teneur en CO2 de l'atmosphère au cours des 4 derniers cycles glaciaire-interglaciaires, à partir de l'analyse de la carotte de Vostok (Antarctique) : implications sur l'évolution du climat et du cycle du carbone

Abstract : The 420 000-year climatic and atmospheric record represented by the Vostok ice core, gives a unique opportunity to reconstruct evolution of atmospheric carbon dioxide (CO2) content for the last 4 glacial- interglacial cycles. The atmospheric significance of CO2 deduced from the Vostok core is discussed taking into account physical processes likely to alter information and measurements of O2/N2 ratio developed in this work. We also compare Vostok CO2 record with ones from other Antarctic ice cores. We show that atmospheric CO2 content for the interglacial stages is 280-300 ppmv (part per million by volume), until anthropogenic disturbance, whereas CO2 concentration into the atmosphere is about 180 ppmv during glacials. These variations parallel those of Antarctic temperature, which have amplitude of about 10°C. Reasons of climatic changes are still poorly understood. By comparing variations of CO2 with regard to those of high North latitude temperatures, sea level and dust concentration in Vostok ice, this work points out the causality links between these parameters. Comparing Vostok with other climatic records (from the North or marine ones), we propose mechanisms able to explain glacial to interglacial changes of atmospheric CO2 content and able to link the events characterising climatic oscillations. This work stresses on the major role of the Southern Hemisphere and particularly that of sea-ice in Southern Ocean.
Complete list of metadatas

Cited literature [207 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00701284
Contributor : Pascale Talour <>
Submitted on : Friday, May 25, 2012 - 9:03:17 AM
Last modification on : Thursday, November 19, 2020 - 3:54:26 PM
Long-term archiving on: : Friday, November 30, 2012 - 12:25:19 PM

Identifiers

  • HAL Id : tel-00701284, version 1

Collections

Citation

Laurence Pepin. Variations de la teneur en CO2 de l'atmosphère au cours des 4 derniers cycles glaciaire-interglaciaires, à partir de l'analyse de la carotte de Vostok (Antarctique) : implications sur l'évolution du climat et du cycle du carbone. Glaciologie. Université Joseph-Fourier - Grenoble I, 2000. Français. ⟨tel-00701284⟩

Share

Metrics

Record views

1643

Files downloads

34595