Changes in Oxygen Isotopes Composition of Precipitation over Tibetan Plateau during Cenozoic

Svetlana Botsyun1, Pierre Sepulchre1, Yannick Donnadieu1, Camille M Risi2 and Frederic Fluteau3, (1)LSCE Laboratoire des Sciences du Climat et de l'Environnement, Gif-Sur-Yvette Cedex, France, (2)Laboratoire de Météorologie Dynamique, Paris, France, (3)Université Paris Cité, Institut de Physique du Globe de Paris, Paris, France
Abstract:
Despite the increasing role of the stable oxygen isotopes measurements for reconstructing mountains belts paleoelevation, some issues remain that lead to a large uncertainty in paleoelevation estimationes. Among them, the use of modern isotopic lapse rate with no account of climate change linked to lower topography can lead to misinterpretation of uplift rates. In this study, we use the atmospheric general circulation model LMDZ-iso to simulate changes in isotopic composition of precipitation due to uplift of the Himalayas and Tibetan plateau. Various scenarios of TP growth have been applied together with Paleocene, Eocene, Oligocene and Miocene boundary conditions. Our simulations allow us to estimate the magnitude of precipitation, temperature and wind field changes related to the spatial and temporal evolution of the Tibetan Plateau and Himalayas. Such changes affected the isotopic composition of precipitation during the Cenozoic.We investigate the impact of these changes on the isotopic lapse rate and the implications for paleoelevation estimates.
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