Variations climatiques interannuelles à interdécennales dans le Pacifique Tropical telles qu’enregistrées par les traceurs géochimiques contenus dans les coraux massifs

Abstract : Tropical paleoclimate studies are extremely important in order to increase our knowledge of climate variability linked to global change and, finally, to improve climate forecasts. In this way, massive corals are excellent recorders of tropical marine climate. Geochemical proxies contained in coral skeleton are linked to environmental parameters. This work points out the great interest of multiproxy studies (stable isotopes: δ18O and δ13C and trace elements such as Sr/Ca, Mg/Ca, U/Ca or Ba/Ca) to understand the variability of sea surface temperature and salinity. Existing methods as well as new ones developed in the calibration phase are then employed. More than 500 years of temperature and salinity history are continuously reconstructed. They show clear decadal variations, which are essentially due to water mass currents in the southern part of New Caledonia. Strong ENSO events (El Niño Southern Oscillation) have also been recorded circa 1600 A.D. The other study site, Wallis, has a climatology strongly linked to SPCZ (South Pacific Convergence Zone) variability. Finally, these results are summarized and a synthesis of various climate indices in the tropics is produced, taking into account these new results.
Complete list of metadatas

http://hal.ird.fr/tel-01172163
Contributor : Isabelle Gasser <>
Submitted on : Tuesday, July 7, 2015 - 1:37:39 AM
Last modification on : Saturday, April 20, 2019 - 1:57:50 AM
Long-term archiving on : Wednesday, April 26, 2017 - 12:31:46 AM

Identifiers

  • HAL Id : tel-01172163, version 1

Collections

IRD | EPHE | INSU | PSL

Citation

Timothée Ourbak. Variations climatiques interannuelles à interdécennales dans le Pacifique Tropical telles qu’enregistrées par les traceurs géochimiques contenus dans les coraux massifs. Milieux et Changements globaux. Université de Bordeaux 1, 2006. Français. ⟨NNT : 3193⟩. ⟨tel-01172163⟩

Share

Metrics

Record views

300

Files downloads

799