Antarctic Precipitation: remote sensing and modelling in a General Circulation Model
Antarctica is an immense continent made of ice. This region remains to this day one of the most unknown regions of our planet Earth. It contains nearly 90% of the world's fresh water, and in the current situation of global warming, this frozen reservoir is under serious threat. In the absence o...
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ftinsu:oai:HAL:tel-03625070v1 2023-11-05T03:34:35+01:00 Antarctic Precipitation: remote sensing and modelling in a General Circulation Model Précipitations en Antarctique : de leur observation par télédétection à leur représentation dans un modèle de climat global. Lemonnier, Florentin Laboratoire de Météorologie Dynamique (UMR 8539) (LMD) Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL) Sorbonne Université Chantal Claud Jean-Baptiste Madeleine 2019-12-03 https://insu.hal.science/tel-03625070 https://insu.hal.science/tel-03625070/document https://insu.hal.science/tel-03625070/file/Th%C3%A8se%20de%20doctorat.pdf fr fre HAL CCSD tel-03625070 https://insu.hal.science/tel-03625070 https://insu.hal.science/tel-03625070/document https://insu.hal.science/tel-03625070/file/Th%C3%A8se%20de%20doctorat.pdf info:eu-repo/semantics/OpenAccess https://insu.hal.science/tel-03625070 Climatologie. Sorbonne Université, 2019. Français. ⟨NNT : ⟩ Antarctic Precipitation Climate Modelling Remote sensing Précipitations Antarctique Climat Modélisation Télédétection [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology info:eu-repo/semantics/doctoralThesis Theses 2019 ftinsu 2023-10-11T16:30:50Z Antarctica is an immense continent made of ice. This region remains to this day one of the most unknown regions of our planet Earth. It contains nearly 90% of the world's fresh water, and in the current situation of global warming, this frozen reservoir is under serious threat. In the absence of reliable observations or efficient climate models, it is so far difficult to verify what is happening in Antarctica, and how it may evolve in the coming decades. Indeed, some studies predict significant ice melt in the west, other studies predict snow accumulation at the surface of its eastern region, mostly by precipitation events. It is, however, difficult to know if one of these two processes takes priority over the other, and which one.The CloudSat satellite is the only precipitation survey tool available on the continental scale. However, there are significant uncertainties about its measurements and the confidence that can be given to it is inevitably very low. Using precisely calibrated radar instruments deployed on the Dumont d'Urville coast station and the Princess Elisabeth continental station, we compared observations of precipitation from both surface and space. Comparison of these observations between the two datasets allowed to validate the satellite's precipitation measurements by re-evaluating an uncertainty on the measurement -- initially between 150 and 250% -- to less than 24%.This result gives more confidence to the measurements of this satellite, and from four years of continuous precipitation observation, we have developed the first three-dimensional and model-independent climatology of snowfall in Antarctica. Comparison of this dataset with theoretical precipitation rates calculated from the forced uplift of an air mass along a topographic slope shows that snowfall appears to be controlled at the first order by large-scale advection and forced uplift of wet flows against topography.We compared this dataset to the global climate model LMDz to assess its capability to represent precipitation over ... Doctoral or Postdoctoral Thesis Antarc* Antarctic Antarctica Antarctique* Institut national des sciences de l'Univers: HAL-INSU |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
French |
topic |
Antarctic Precipitation Climate Modelling Remote sensing Précipitations Antarctique Climat Modélisation Télédétection [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology |
spellingShingle |
Antarctic Precipitation Climate Modelling Remote sensing Précipitations Antarctique Climat Modélisation Télédétection [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology Lemonnier, Florentin Antarctic Precipitation: remote sensing and modelling in a General Circulation Model |
topic_facet |
Antarctic Precipitation Climate Modelling Remote sensing Précipitations Antarctique Climat Modélisation Télédétection [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology |
description |
Antarctica is an immense continent made of ice. This region remains to this day one of the most unknown regions of our planet Earth. It contains nearly 90% of the world's fresh water, and in the current situation of global warming, this frozen reservoir is under serious threat. In the absence of reliable observations or efficient climate models, it is so far difficult to verify what is happening in Antarctica, and how it may evolve in the coming decades. Indeed, some studies predict significant ice melt in the west, other studies predict snow accumulation at the surface of its eastern region, mostly by precipitation events. It is, however, difficult to know if one of these two processes takes priority over the other, and which one.The CloudSat satellite is the only precipitation survey tool available on the continental scale. However, there are significant uncertainties about its measurements and the confidence that can be given to it is inevitably very low. Using precisely calibrated radar instruments deployed on the Dumont d'Urville coast station and the Princess Elisabeth continental station, we compared observations of precipitation from both surface and space. Comparison of these observations between the two datasets allowed to validate the satellite's precipitation measurements by re-evaluating an uncertainty on the measurement -- initially between 150 and 250% -- to less than 24%.This result gives more confidence to the measurements of this satellite, and from four years of continuous precipitation observation, we have developed the first three-dimensional and model-independent climatology of snowfall in Antarctica. Comparison of this dataset with theoretical precipitation rates calculated from the forced uplift of an air mass along a topographic slope shows that snowfall appears to be controlled at the first order by large-scale advection and forced uplift of wet flows against topography.We compared this dataset to the global climate model LMDz to assess its capability to represent precipitation over ... |
author2 |
Laboratoire de Météorologie Dynamique (UMR 8539) (LMD) Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL) Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL) Sorbonne Université Chantal Claud Jean-Baptiste Madeleine |
format |
Doctoral or Postdoctoral Thesis |
author |
Lemonnier, Florentin |
author_facet |
Lemonnier, Florentin |
author_sort |
Lemonnier, Florentin |
title |
Antarctic Precipitation: remote sensing and modelling in a General Circulation Model |
title_short |
Antarctic Precipitation: remote sensing and modelling in a General Circulation Model |
title_full |
Antarctic Precipitation: remote sensing and modelling in a General Circulation Model |
title_fullStr |
Antarctic Precipitation: remote sensing and modelling in a General Circulation Model |
title_full_unstemmed |
Antarctic Precipitation: remote sensing and modelling in a General Circulation Model |
title_sort |
antarctic precipitation: remote sensing and modelling in a general circulation model |
publisher |
HAL CCSD |
publishDate |
2019 |
url |
https://insu.hal.science/tel-03625070 https://insu.hal.science/tel-03625070/document https://insu.hal.science/tel-03625070/file/Th%C3%A8se%20de%20doctorat.pdf |
genre |
Antarc* Antarctic Antarctica Antarctique* |
genre_facet |
Antarc* Antarctic Antarctica Antarctique* |
op_source |
https://insu.hal.science/tel-03625070 Climatologie. Sorbonne Université, 2019. Français. ⟨NNT : ⟩ |
op_relation |
tel-03625070 https://insu.hal.science/tel-03625070 https://insu.hal.science/tel-03625070/document https://insu.hal.science/tel-03625070/file/Th%C3%A8se%20de%20doctorat.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1781705267246792704 |