Skip to Main content Skip to Navigation
Theses

Méthodes bayésiennes semi-paramétriques d'extraction et de sélection de variables dans le cadre de la dendroclimatologie

Abstract : As stated by the Intergovernmental Panel on Climate Change (IPCC), it is important to reconstruct past climate to accurately assess the actual climatic change. A large number of researchers have worked to develop procedures to reconstruct past temperatures or precipitation with indirect climatic indicators. These methods are generally based on statistical arguments but the estimation of uncertainties associated to these reconstructions remains an active research field in statistics and in climate studies. The main goal of this thesis is to propose and study novel statistical methods that allow a precise estimation of uncertainties when reconstructing from tree-ring measurements data. Generally, climatic reconstructions from tree-ring observations are based on two steps. Firstly, a hidden environmental hidden variable, common to a collection of tree-ring measurements series, has to be adequately inferred. Secondly, this extracted signal has to be explained with the relevant climatic variables. For these two steps, we have opted to work within a semi-parametric bayesian framework that reduces the number of assumptions and allows to include prior information from the practitioner. Concerning the extraction of the common signal, we propose a model which can catch high and low frequencies contained in tree-rings. This was not possible with previous dendroclimatological methods. For the second step, we have developed a bayesian Generalized Additive Model (GAM) to explore potential links between the extracted signal and some climatic variables. This allows the modeling of non-linear relationships among variables and strongly differs from past dendrochronological methods. From a statistical perspective, a new selection scheme for bayesien GAM was also proposed and studied.
Document type :
Theses
Complete list of metadatas

Cited literature [84 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00636704
Contributor : Abes Star :  Contact
Submitted on : Friday, October 28, 2011 - 10:32:14 AM
Last modification on : Friday, October 23, 2020 - 5:03:41 PM
Long-term archiving on: : Monday, January 30, 2012 - 11:14:18 AM

File

VA2_GUIN_OPHELIE_14042011.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-00636704, version 1

Collections

Citation

Ophélie Guin. Méthodes bayésiennes semi-paramétriques d'extraction et de sélection de variables dans le cadre de la dendroclimatologie. Autre [q-bio.OT]. Université Paris Sud - Paris XI, 2011. Français. ⟨NNT : 2011PA112043⟩. ⟨tel-00636704⟩

Share

Metrics

Record views

506

Files downloads

545