A new Himalayan ice core CH4 record: possible hints at the preindustrial latitudinal gradient

International audience Two ice cores recovered from the Himalayan East Rongbuk (ER) Glacier on the northeast saddle of Mt. Qomolangma (Everest) (28°01' N, 86°58' E, 6518 m above sea level) give access to a tentative record of past Himalayan atmospheric mixing ratio of CH4 spanning the past...

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Bibliographic Details
Published in:Climate of the Past
Main Authors: Hou, S., Chappellaz, J., Raynaud, D., Masson-Delmotte, V., Jouzel, J., Bousquet, P., Hauglustaine, D.
Other Authors: Nanjing University (NJU), 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), Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), Modelling the Earth Response to Multiple Anthropogenic Interactions and Dynamics (MERMAID)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2013
Subjects:
Online Access:https://hal.archives-ouvertes.fr/hal-03104123
https://hal.archives-ouvertes.fr/hal-03104123/document
https://hal.archives-ouvertes.fr/hal-03104123/file/cp-9-2549-2013.pdf
https://doi.org/10.5194/CP-9-2549-2013
Description
Summary:International audience Two ice cores recovered from the Himalayan East Rongbuk (ER) Glacier on the northeast saddle of Mt. Qomolangma (Everest) (28°01' N, 86°58' E, 6518 m above sea level) give access to a tentative record of past Himalayan atmospheric mixing ratio of CH4 spanning the past 1200 yr. The major part of the record is affected by artifacts probably due to in situ production. After selecting what may represent the true atmospheric mixing ratio, an average of 749 ± 25 ppbv of CH4 is estimated for the late preindustrial Holocene, which is ~ 36 ± 17 (~ 73 ± 18) ppbv higher than the atmospheric levels recorded in the Greenland (Antarctic) ice cores. A comparison of these new data with model simulations of the CH4 latitudinal gradient suggests either that the models do not get a correct balance between high and low latitude CH4 sources, or that the filtered CH4 profile from the ER cores remains biased by small artifacts.