• Arakawa, A., 2000: Future development of general circulation models. General Circulation Model Development: Past, Present, and Future, D. A. Randall, Ed., Academic Press, 721–780.

    • Search Google Scholar
    • Export Citation
  • Benjamin, S. G., 1989: An isentropic mesoα-scale analysis system and its sensitivity to aircraft and surface observations. Mon. Wea. Rev., 117, 15861603.

    • Search Google Scholar
    • Export Citation
  • Boer, G. J., 1992: Some results from an intercomparison of the climates simulated by 14 atmospheric general circulation models. J. Geophys. Res., 97, 12 77112 786.

    • Search Google Scholar
    • Export Citation
  • Carpenter, R. L., Jr., , K. K. Droegemeier, , P. R. Woodward, , and C. E. Hane, 1990: Application of the piecewise parabolic method (PPM) to meteorological modeling. Mon. Wea. Rev., 118, 586612.

    • Search Google Scholar
    • Export Citation
  • Colella, P., , and P. R. Woodward, 1984: The piecewise parabolic method (PPM) for gas-dynamical simulations. J. Comput. Phys., 54, 174201.

    • Search Google Scholar
    • Export Citation
  • Hsu, Y.-J. G., , and A. Arakawa, 1990: Numerical modeling of the atmosphere with an isentropic vertical coordinate. Mon. Wea. Rev., 118, 19331959.

    • Search Google Scholar
    • Export Citation
  • Johnson, D. R., 1997: “General coldness of climate models” and the Second Law: Implications for modeling the earth system. J. Climate, 10, 28262846.

    • Search Google Scholar
    • Export Citation
  • Kållberg, P., , A. Simmons, , S. Uppala, , and M. Fuentes, 2004: The ERA-40 archive. Tech. Rep. ERA-40 Project Rep. 17, European Centre for Medium-Range Weather Forecasts, Reading, United Kingdom, 35 pp.

    • Search Google Scholar
    • Export Citation
  • Kasahara, A., 1974: Various vertical coordinate system used for numerical weather prediction. Mon. Wea. Rev., 102, 33023318.

  • Kistler, R., and Coauthors, 2001: The NCEP–NCAR 50-Year Reanalysis: Monthly means CD-ROM and documentation. Bull. Amer. Meteor. Soc., 82, 247268.

    • Search Google Scholar
    • Export Citation
  • Lin, S.-J., 2004: A “vertically Lagrangian” finite volume dynamical core for global models. Mon. Wea. Rev., 132, 22932307.

  • Lin, S.-J., , and R. B. Rood, 1996: Multidimensional flux form semi-Lagrangian transport schemes. Mon. Wea. Rev., 124, 20462070.

  • Lin, S.-J., , and R. B. Rood, 1997: An explicit flux-form semi-Lagrangian general circulation shallow water model on the sphere. Quart. J. Roy. Meteor. Soc., 123, 24772498.

    • Search Google Scholar
    • Export Citation
  • Lin, W. Y., , and M. H. Zhang, 2004: Evaluation of clouds and their radiative effects simulated by the NCAR Community Atmosphere Model against satellite observations. J. Climate, 17, 33023318.

    • Search Google Scholar
    • Export Citation
  • Mahowald, N. M., , R. A. Plumb, , P. J. Rasch, , J. del Corral, , F. Sassi, , and W. Heres, 2002: Stratospheric transport in a three-dimensional isentropic coordinate model. J. Geophys. Res., 107, 4254, doi:10.1029/2001JD001313.

    • Search Google Scholar
    • Export Citation
  • Schaack, T. K., , T. H. Zapotoncy, , A. J. Lenzen, , and D. R. Johnson, 2004: Global climate simulation with the University of Wisconsin global hybrid isentropic coordinate model. J. Climate, 17, 29983016.

    • Search Google Scholar
    • Export Citation
  • Skamarock, W. C., 2006: Positive-definite and monotonic limters for unrestricted-time-step transport schemes. Mon. Wea. Rev., 134, 22412250.

    • Search Google Scholar
    • Export Citation
  • Solomon, S., , D. Qin, , M. Manning, , M. Marquis, , K. Averyt, , M. M. B. Tignor, , H. L. Miller Jr., , and Z. Chen, Eds., 2007: Climate Change 2007: The Physical Science Basis. Cambridge University Press, 996 pp.

    • Search Google Scholar
    • Export Citation
  • Starr, V. P., 1945: A quasi-Lagrangian system of hydrodynamical equations. J. Meteor., 2, 227237.

  • Sundqvist, H., 1976: On vertical interpolation and truncation in connection with use of sigma system. Atmosphere, 14, 3752.

  • Webster, S., , J. Thuburn, , B. Hoskins, , and M. Rodwell, 1999: Further development of a hybrid-isentropic GCM. Quart. J. Roy. Meteor. Soc., 125, 23052331.

    • Search Google Scholar
    • Export Citation
  • Williamson, D. L., 1983: Description of NCAR Community Climate Model (CCM0B). NCAR Tech. Note NCAR/TN-210+STR, Boulder, CO, 88 pp. [NTIS PB-83231068.]

    • Search Google Scholar
    • Export Citation
  • Zhu, Z., , and E. K. Schneider, 1997: Improvement in stratosphere simulation with a hybrid σθ coordinate. Quart. J. Roy. Meteor. Soc., 123, 851862.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 9 9 2
PDF Downloads 0 0 0

Climate Simulations with an Isentropic Finite-Volume Dynamical Core

View More View Less
  • 1 National Center for Atmospheric Research, Boulder, Colorado
  • | 2 Pacific Northwest National Laboratory, Richland, Washington
© Get Permissions
Restricted access

Abstract

This paper discusses the impact of changing the vertical coordinate from a hybrid pressure to a hybrid-isentropic coordinate within the finite-volume (FV) dynamical core of the Community Atmosphere Model (CAM). Results from a 20-yr climate simulation using the new model coordinate configuration are compared to control simulations produced by the Eulerian spectral and FV dynamical cores of CAM, which both use a pressure-based (σP) coordinate. The same physical parameterization package is employed in all three dynamical cores.

The isentropic modeling framework significantly alters the simulated climatology and has several desirable features. The revised model produces a better representation of heat transport processes in the atmosphere leading to much improved atmospheric temperatures. The authors show that the isentropic model is very effective in reducing the long-standing cold temperature bias in the upper troposphere and lower stratosphere, a deficiency shared among most climate models. The warmer upper troposphere and stratosphere seen in the isentropic model reduces the global coverage of high clouds, which is in better agreement with observations. The isentropic model also shows improvements in the simulated wintertime mean sea level pressure field in the Northern Hemisphere.

Corresponding author address: Chih-Chieh Chen, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000. E-mail: cchen@ucar.edu

Abstract

This paper discusses the impact of changing the vertical coordinate from a hybrid pressure to a hybrid-isentropic coordinate within the finite-volume (FV) dynamical core of the Community Atmosphere Model (CAM). Results from a 20-yr climate simulation using the new model coordinate configuration are compared to control simulations produced by the Eulerian spectral and FV dynamical cores of CAM, which both use a pressure-based (σP) coordinate. The same physical parameterization package is employed in all three dynamical cores.

The isentropic modeling framework significantly alters the simulated climatology and has several desirable features. The revised model produces a better representation of heat transport processes in the atmosphere leading to much improved atmospheric temperatures. The authors show that the isentropic model is very effective in reducing the long-standing cold temperature bias in the upper troposphere and lower stratosphere, a deficiency shared among most climate models. The warmer upper troposphere and stratosphere seen in the isentropic model reduces the global coverage of high clouds, which is in better agreement with observations. The isentropic model also shows improvements in the simulated wintertime mean sea level pressure field in the Northern Hemisphere.

Corresponding author address: Chih-Chieh Chen, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000. E-mail: cchen@ucar.edu
Save