# Simulation of the isotopic composition of stratospheric water vapour - Part 1: Description and evaluation of the EMAC model

Eichinger, R.; Jöckel, P.; Brinkop, S.; Werner, M.; Lossow, S.

Abstract:
This modelling study aims at an improved understanding of the processes that determine the water vapour budget in the stratosphere by means of the investigation of water isotope ratios. An additional (and separate from the actual) hydrological cycle has been introduced into the chemistry–climate model EMAC, including the water isotopologues HDO and H$_{2}$$^{18}$O and their physical fractionation processes. Additionally an explicit computation of the contribution of methane oxidation to H$_{2}$O and HDO has been incorporated. The model expansions allow detailed analyses of water vapour and its isotope ratio with respect to deuterium throughout the stratosphere and in the transition region to the troposphere. In order to assure the correct representation of the water isotopologues in the model’s hydrological cycle, the expanded system has been evaluated in several steps. The physical fractionation effects have been evaluated by comparison of the simulated isotopic composition of precipitation with measurements from a ground-based network (GNIP) and with the results from the isotopologue-enabled general circulation model ECHAM5-wiso. ... mehr

 Zugehörige Institution(en) am KIT Institut für Meteorologie und Klimaforschung - Atmosphärische Spurenstoffe und Fernerkundung (IMK-ASF) Publikationstyp Zeitschriftenaufsatz Jahr 2015 Sprache Englisch Identifikator ISSN: 1680-7316, 1680-7324KITopen ID: 1000058070 HGF-Programm 12.04.05; LK 01 Erschienen in Atmospheric chemistry and physics Band 15 Heft 10 Seiten 5537-5555
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