QTCMs - Quasi-equilibrium Tropical Circulation model

Research Areas

People

Publications

Software

Introduction Quasi-equilibrium Tropical Circulation Models (QTCMs) are part of the research effort of the Climate Systems Interaction (CSI) group, in the Dept. of Atmospheric Sciences at UCLA. QTCMs are models of intermediate complexity suitable for the modeling of tropical climate and its variability. It occupies a niche among climate models between complex general circulation models and simple models.

QTCM1 (version 2.2): Anomalous precipitation from a simulation forced by observed sea surface temperatures 1982-1998. Larger image with animation control.

The primitive-equation-based dynamical framework is constructed using analytical solutions from the quasi-equilibrium convective parameterization as the first basis function in a Galerkin representation of vertical structure. A uniqueness of the QTCM is its balanced treatment of dynamics and physical parameterizations. It includes a linearized longwave radiation scheme, simple cloud prediction and shortwave radiation schemes, and the Simple-Land (SLand) land model.

QTCM1

QTCM1 includes a single deep convective mode in the vertical thermodynamic structure and two components (baroclinic and barotropic) in the vertical structure of velocity. It is computationally light (5min on a Sun Ultra2 at 5.625x3.75 resolution and 1.5 minutes on a Pentium-4/Linux workstation) and easy to diagnose.

QTCM1 Version 2.3 - current-release (August 2002)

Contact

For scientific questions, please contact:
  David Neelin: neelin@atmos.ucla.edu , (310) 206-3734 (o)
  Ning Zeng: zeng@atmos.ucla.edu , (310) 825-3439 (o)
  Hui Su: hui@atmos.ucla.edu , (310) 825-4432 (o)
  Matthias Munnich: munnich@atmos.ucla.edu , (310) 794-5899 (o)

For technical questions, please contact:
  Hui Su: hui@atmos.ucla.edu , (310) 825-4432 (o)

Development team

Initial QTCM Publications

• Neelin, J. D., and N. Zeng, 2000: A quasi-equilibrium tropical circulation model---formulation. J. Atmos. Sci. , 57, 1741-1766.
  Paper (PDF 438KB).
• Zeng, N., J. D. Neelin, and C. Chou, 2000: A quasi-equilibrium tropical circulation model---implementation and simulation. J. Atmos. Sci., 57, 1767-1796. Paper (PDF 2.7MB).
• Lin, J. W.-B., J. D. Neelin, and N. Zeng, 2000: Maintenance of tropical variability: Impact of evaporation-wind feedback and midlatitude storms. J. Atmos. Sci., 57, 2793-2823. Paper (PDF 1.4MB)
  
• Zeng, N., J. D. Neelin, C. Chou, J. W.-B. Lin, H. Su, 2000: Climate and variability in the first quasi-equilibrium tropical circulation model. General Circulation Model Development: Past, Present, and Future, Academic Press, 457--488. Paper (gzipped tar, 5 Mb uncompressed). PS file (gzipped, 1.3 Mb).
• Other QTCM related publications

Group Internal Use

Archive of sample figures

Figure 1. Model (QTCM1V2.0) simulated monthly mean precipitation on the equator through the period 1982-1998.

Figure 1. Model (QTCM1V2.0) climatology January mean precipitation for the period 1982-1998.