Simulations du climat des calottes de glace
The subject of this work is the numerical simulation of the climate of large ice sheets, in particular the existing ice sheets of Greenland and Antarctica, in different climatic conditions using atmospheric general circulation models (GCMs). The LMDz stretched-grid GCM was adapted for the specificit...
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Other Authors: | , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | French |
Published: |
HAL CCSD
1997
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Subjects: | |
Online Access: | https://theses.hal.science/tel-00716408 https://theses.hal.science/tel-00716408/document https://theses.hal.science/tel-00716408/file/These-Krinner-1997.pdf |
Summary: | The subject of this work is the numerical simulation of the climate of large ice sheets, in particular the existing ice sheets of Greenland and Antarctica, in different climatic conditions using atmospheric general circulation models (GCMs). The LMDz stretched-grid GCM was adapted for the specificities of the polar climate and validated for the present-day climate. The stretched-grid approach, allowing to run the GCM at high spatial resolutions (about 100 km) over the region of interest at a reasonable numeric cost, was validated by analysing the simulated atmospheric dynamics at the edge of the high resolution regions using a cyclone tracking scheme. Simulations of the climate of the Last Glacial Maximum (LGM) were carried out for Greenland and Antarctica. These simulations were analysed in the light of the available ice core records. A possible explanation of the water isotope - borehole temperature confiict in central Greenland, based on simulated changes of local surface climate parameters, could be proposed. This is the first time that the stretched-grid approach was used in a GCM for longer term simulations of the polar climate. The paleo-climate simulations with the LMDz GCM were run at an unprecedented high horizontal resolution. Finally, the ice sheet LGM climate simulated by several GCMs within the framework of the international project PMIP (Paleoclimate Modelling Intercomparison Programme) was analysed and implications of the results for the interpretation of ice core records were discussed. Ce travail traite de la simulation numérique du climat des grandes calottes de glace, en particulier des calottes de l'Antarctique et du Groenland, toujours existantes, dans des conditions climatiques différentes, à l'aide de modèles de circulation générale de l'atmosphère (MCGA). Le MCGA à grille variable LMDz a été adapté aux spécificités du climat polaire et validé pour le climat actuel. L'approche d'une grille variable, qui permet d'utiliser le MCGA à haute résolution spatiale (autour de 100 km) sur la ... |
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