1. Multimodel assessment of the upper troposphere and lower stratosphere : Tropics and global trends
- Author
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W. Tian, Juan A. Añel, John Scinocca, Stefanie Kremser, Steven Pawson, Patrick Jöckel, Giovanni Pitari, Kiyotaka Shibata, Slimane Bekki, Masatomo Fujiwara, Jung-Hyun Kim, Ch. Brühl, Jean-Francois Lamarque, Olaf Morgenstern, Martine Michou, Dan Smale, Andrew Gettelman, H. Teyssèdre, Thomas Birner, Steven C. Hardiman, John A. Pyle, Michaela I. Hegglin, Eva Mancini, Sandip Dhomse, Theodore G. Shepherd, P. Braesike, Martin Dameris, Seok-Woo Son, Martyn P. Chipperfield, Markus Rex, Marion Marchand, Douglas E. Kinnison, Hideharu Akiyoshi, D. A. Plummer, N. Butchart, Eugene Rozanov, John Austin, Hella Garny, National Center for Atmospheric Research [Boulder] (NCAR), Department of Physics [Toronto], University of Toronto, Department of Atmospheric and Oceanic Sciences [Montréal], McGill University = Université McGill [Montréal, Canada], Hokkaido University [Sapporo, Japan], Department of Atmospheric Science [Fort Collins], Colorado State University [Fort Collins] (CSU), Freie Universität Berlin, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Environmental Physics Laboratory (EPhysLab), Universidade de Vigo, National Institute for Environmental Studies (NIES), NOAA Geophysical Fluid Dynamics Laboratory (GFDL), National Oceanic and Atmospheric Administration (NOAA), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Chemistry [Cambridge, UK], University of Cambridge [UK] (CAM), Max-Planck-Institut für Chemie (MPIC), Max-Planck-Gesellschaft, United Kingdom Met Office [Exeter], School of Earth and Environment [Leeds] (SEE), University of Leeds, DLR Institut für Physik der Atmosphäre (IPA), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), Institute for Climate and Atmospheric Science [Leeds] (ICAS), University of Leeds-University of Leeds, University of L'Aquila [Italy] (UNIVAQ), Groupe d'étude de l'atmosphère météorologique (CNRM-GAME), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS), National Institute of Water and Atmospheric Research [Lauder] (NIWA), NASA Goddard Space Flight Center (GSFC), Environment and Climate Change Canada, Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC), Canadian Centre for Climate Modelling and Analysis (CCCma), Meteorological Research Institute [Tsukuba] (MRI), Japan Meteorological Agency (JMA), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,Tropopause ,Climate ,TTL ,0207 environmental engineering ,Soil Science ,chemistry-climate models ,02 engineering and technology ,Aquatic Science ,Oceanography ,Atmospheric sciences ,01 natural sciences ,Troposphere ,Geochemistry and Petrology ,Earth and Planetary Sciences (miscellaneous) ,Extratropical cyclone ,020701 environmental engineering ,Stratosphere ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Water Science and Technology ,[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph] ,Ecology ,Cloud fraction ,Paleontology ,Humidity ,Forestry ,Chemistry ,Geophysics ,13. Climate action ,Space and Planetary Science ,Climatology ,Dynamik der Atmosphäre ,Climate model ,CCMVal ,Water vapor - Abstract
International audience; The performance of 18 coupled Chemistry Climate Models (CCMs) in the Tropical Tropopause Layer (TTL) is evaluated using qualitative and quantitative diagnostics. Trends in tropopause quantities in the tropics and the extratropical Upper Troposphere and Lower Stratosphere (UTLS) are analyzed. A quantitative grading methodology for evaluating CCMs is extended to include variability and used to develop four different grades for tropical tropopause temperature and pressure, water vapor and ozone. Four of the 18 models and the multi‐model mean meet quantitative and qualitative standards for reproducing key processes in the TTL. Several diagnostics are performed on a subset of the models analyzing the Tropopause Inversion Layer (TIL), Lagrangian cold point and TTL transit time. Historical decreases in tropical tropopause pressure and decreases in water vapor are simulated, lending confidence to future projections. The models simulate continued decreases in tropopause pressure in the 21st century, along with ∼1K increases per century in cold point tropopause temperature and 0.5–1 ppmv per century increases in water vapor above the tropical tropopause. TTL water vapor increases below the cold point. In two models, these trends are associated with 35% increases in TTL cloud fraction. These changes indicate significant perturbations to TTL processes, specifically to deep convective heating and humidity transport. Ozone in the extratropical lowermost stratosphere has significant and hemispheric asymmetric trends. O3 is projected to increase by nearly 30% due to ozone recovery in the Southern Hemisphere (SH) and due to enhancements in the stratospheric circulation. These UTLS ozone trends may have significant effects in the TTL and the troposphere.
- Published
- 2010