• Open Access

Implementation of the Quasi-equilibrium Tropical Circulation Model 2 (QTCM2): Global simulations and convection sensitivity to free tropospheric moisture

Authors

  • Benjamin R. Lintner,

    Corresponding author
    1. Department of Environmental Sciences, Rutgers, State University of New Jersey, New Brunswick, New Jersey, USA.
    Search for more papers by this author
  • Gilles Bellon,

    1. Centre National de Recherches Météorologiques, Centre National de la Recherche Scientifique, Météo-France, Toulouse, France.
    Search for more papers by this author
  • Adam H. Sobel,

    1. Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York, USA.
    2. Department of Earth and Environmental Sciences, Columbia University, New York, New York, USA.
    3. Lamont-Doherty Earth Observatory, Columbia University, New York, New York, USA.
    Search for more papers by this author
  • Daehyun Kim,

    1. Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York, USA.
    Search for more papers by this author
  • J. David Neelin

    1. Department of Atmospheric and Oceanic Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California, USA.
    Search for more papers by this author

Corresponding author: B. R. Lintner, Department of Environmental Sciences, Rutgers, State University of New Jersey, 14 College Farm Rd., New Brunswick, NJ 08901-8551, USA. (lintner@envsci.rutgers.edu)

Abstract

[1] The implementation of the Quasi-equilibrium Tropical Circulation Model 2 (QTCM2), an intermediate level complexity model, is described. Following the approach of Sobel and Neelin (2006), an explicit, prognostic atmospheric boundary layer (ABL) of fixed depth is added to a free troposphere (FT) containing one baroclinic and one barotropic mode. QTCM2 is shown to simulate reasonable climatologies of temperature, moisture, winds, and precipitation, albeit with only modest improvements relative to the predecessor single vertical mode version, QTCM1. The addition of an ABL increases the sharpness of horizontal precipitation and moisture gradients, and the separation of the moisture profile into ABL and FT components allows investigation into the separate roles of these two components in modulating deep convection. Model sensitivity to various convection parameters is explored, with contrasting precipitation responses often seen within the cores of convecting regions and along their margins.

Ancillary