Ice Cores Dating With a New Inverse Method Taking Account of the Flow Modeling Errors
International audience Deep ice cores extracted from Antarctica or Greenland recorded a wide range of past climatic events. In order to contribute to the Quaternary climate system understanding, the calculation of an accurate depth-age relationship is a crucial point. Up to now ice chronologies for...
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HAL CCSD
2007
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Online Access: | https://inria.hal.science/inria-00344648 |
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Open Polar |
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Université Grenoble Alpes: HAL |
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ftunigrenoble |
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English |
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[MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC] |
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[MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC] Lemieux-Dudon, Bénédicte Parrenin, Frédéric Blayo, Eric Ice Cores Dating With a New Inverse Method Taking Account of the Flow Modeling Errors |
topic_facet |
[MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC] |
description |
International audience Deep ice cores extracted from Antarctica or Greenland recorded a wide range of past climatic events. In order to contribute to the Quaternary climate system understanding, the calculation of an accurate depth-age relationship is a crucial point. Up to now ice chronologies for deep ice cores estimated with inverse approaches are based on quite simplified ice-flow models that fail to reproduce flow irregularities and consequently to respect all available set of age markers. We describe in this paper, a new inverse method that takes into account the model uncertainty in order to circumvent the restrictions linked to the use of simplified flow models. This method uses first guesses on two flow physical entities, the ice thinning function and the accumulation rate and then identifies correction functions on both flow entities. We highlight two major benefits brought by this new method: first of all the ability to respect large set of observations and as a consequence, the feasibility to estimate a synchronized common ice chronology for several cores at the same time. This inverse approach relies on a bayesian framework. To respect the positive constraint on the searched correction functions, we assume lognormal probability distribution on one hand for the background errors, but also for one particular set of the observation errors. We test this new inversion method on three cores simultaneously (the two EPICA cores : DC and DML and the Vostok core) and we assimilate more than 150 observations (e.g.: age markers, stratigraphic links,.). We analyze the sensitivity of the solution with respect to the background information, especially the prior error covariance matrix. The confidence intervals based on the posterior covariance matrix calculation, are estimated on the correction functions and for the first time on the overall output chronologies. |
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Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Observatoire des Sciences de l'Univers de Grenoble (OSUG) Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) Modelling, Observations, Identification for Environmental Sciences (MOISE) Inria Grenoble - Rhône-Alpes Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK) Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS) |
format |
Conference Object |
author |
Lemieux-Dudon, Bénédicte Parrenin, Frédéric Blayo, Eric |
author_facet |
Lemieux-Dudon, Bénédicte Parrenin, Frédéric Blayo, Eric |
author_sort |
Lemieux-Dudon, Bénédicte |
title |
Ice Cores Dating With a New Inverse Method Taking Account of the Flow Modeling Errors |
title_short |
Ice Cores Dating With a New Inverse Method Taking Account of the Flow Modeling Errors |
title_full |
Ice Cores Dating With a New Inverse Method Taking Account of the Flow Modeling Errors |
title_fullStr |
Ice Cores Dating With a New Inverse Method Taking Account of the Flow Modeling Errors |
title_full_unstemmed |
Ice Cores Dating With a New Inverse Method Taking Account of the Flow Modeling Errors |
title_sort |
ice cores dating with a new inverse method taking account of the flow modeling errors |
publisher |
HAL CCSD |
publishDate |
2007 |
url |
https://inria.hal.science/inria-00344648 |
op_coverage |
San Fransisco, United States |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Antarc* Antarctica DML EPICA Greenland |
genre_facet |
Antarc* Antarctica DML EPICA Greenland |
op_source |
American Geophysical Union Fall meeting https://inria.hal.science/inria-00344648 American Geophysical Union Fall meeting, Dec 2007, San Fransisco, United States |
op_relation |
inria-00344648 https://inria.hal.science/inria-00344648 |
_version_ |
1798836765223550976 |
spelling |
ftunigrenoble:oai:HAL:inria-00344648v1 2024-05-12T07:56:36+00:00 Ice Cores Dating With a New Inverse Method Taking Account of the Flow Modeling Errors Lemieux-Dudon, Bénédicte Parrenin, Frédéric Blayo, Eric Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Observatoire des Sciences de l'Univers de Grenoble (OSUG) Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) Modelling, Observations, Identification for Environmental Sciences (MOISE) Inria Grenoble - Rhône-Alpes Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK) Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS) San Fransisco, United States 2007-12-10 https://inria.hal.science/inria-00344648 en eng HAL CCSD inria-00344648 https://inria.hal.science/inria-00344648 American Geophysical Union Fall meeting https://inria.hal.science/inria-00344648 American Geophysical Union Fall meeting, Dec 2007, San Fransisco, United States [MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC] info:eu-repo/semantics/conferenceObject Conference papers 2007 ftunigrenoble 2024-04-18T03:12:00Z International audience Deep ice cores extracted from Antarctica or Greenland recorded a wide range of past climatic events. In order to contribute to the Quaternary climate system understanding, the calculation of an accurate depth-age relationship is a crucial point. Up to now ice chronologies for deep ice cores estimated with inverse approaches are based on quite simplified ice-flow models that fail to reproduce flow irregularities and consequently to respect all available set of age markers. We describe in this paper, a new inverse method that takes into account the model uncertainty in order to circumvent the restrictions linked to the use of simplified flow models. This method uses first guesses on two flow physical entities, the ice thinning function and the accumulation rate and then identifies correction functions on both flow entities. We highlight two major benefits brought by this new method: first of all the ability to respect large set of observations and as a consequence, the feasibility to estimate a synchronized common ice chronology for several cores at the same time. This inverse approach relies on a bayesian framework. To respect the positive constraint on the searched correction functions, we assume lognormal probability distribution on one hand for the background errors, but also for one particular set of the observation errors. We test this new inversion method on three cores simultaneously (the two EPICA cores : DC and DML and the Vostok core) and we assimilate more than 150 observations (e.g.: age markers, stratigraphic links,.). We analyze the sensitivity of the solution with respect to the background information, especially the prior error covariance matrix. The confidence intervals based on the posterior covariance matrix calculation, are estimated on the correction functions and for the first time on the overall output chronologies. Conference Object Antarc* Antarctica DML EPICA Greenland Université Grenoble Alpes: HAL Greenland |