Chimie de la carotte EUROCORE (Groenland Central) : variabilité des émissions biologiques au cours du dernier millénaire

• Main Author: Savarino, Joel
• Other Authors: 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), Université Joseph-Fourier - Grenoble I, Michel Legrand
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 1996
• Subjects: carotte Eurocore; Groenland; archivage glaciaire; biomasse; signature chimique; volcanisme; formiate; climat; [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; [SDE.MCG]Environmental Sciences/Global Changes; Greenland; ice core
• Online Access: https://theses.hal.science/tel-00693932; https://theses.hal.science/tel-00693932/document; https://theses.hal.science/tel-00693932/file/These-Savarino-1996.pdf

Polar ice core provide a unique way to obtain informations allowed a better understanding on change in the biogeochemical cycles during the past. If the study of man-made modification during the last two hundred years are numerous, on the other hand there's a lack of work on the natural climat fluctuations that are the medieval warm periode (1200-1300 A.D.) and the little ice age (1300-1800 A.D.). This study cover this time periode and soluble species trapped in the ice from central Greenland are investigate. The principals results of this study are the chemistry of biomass burning recorded in the ice depends on the atmospheric age of the burning plume. The presence of nitrate in elevate concentration seem to be the chemical signature of young biomass burning plumes, frequency and flux of this input are connected to the climate, with high frequency and low flux during warm periodes and low frequency and high flux during cold periodes, Background chemistry suggests a possible presence of particulate ammonium nitrate during pre-industrial time. The absence of high acid sulfuric loading in the atmosphere in pre industrial time seem to be a possible reason for ammonium nitrate formation. Concentrations of formic acids present in the ice are weIl connected with the story of the canadian vegetation. We confirm a relocation of the MSA from summer to winter layers during buriaI. The lack of knowledge of past marine biogenic emissions can 't allow a comparaison between our marine biogenic tracers and other physic or climatic parameters. L'archivage glaciaire représente un moyen privilégié d'obtenir des informations permettant une meilleure compréhension des cycles biogéochimiques au cours des temps passés. Si les perturbations induites par l'homme durant les deux cents dernières années ont été abondamment étudiées, les fluctuations naturelles du climat, sur une période recoupant l'Optimum Médiéval (1200-1300 AD.) et le Petit Age de Glace (1300-1800 A.D<), souffrent, quant à elles, du manque d'études détaillées. Nos ...