New

Check out the CM1 Users Group website: a forum for CM1 users to ask questions, share code, post results, etc.

Code

Download the code here. (Most recent version: cm1r12, uploaded on 12 August 2008)

Documentation

About CM1:

• Answers to frequently asked questions about CM1.
• Original Model Formulation (pdf): chapter from George Bryan's Ph.D. thesis. (applies to cm1r1)
• Acknowledgments.

Using CM1:

• A brief summary of how to run cm1.
• CHANGES in release 12 -- new features, modifications, and code fixes for the newest version (12 August 2008)
  • History of all CHANGES (from r2 to present)
• README.namelist -- explains the various settings in the namelist.input file.
• Known bugs
• Instructions for adding a new microphysics scheme to CM1 (pdf)
• Sample submission scripts for NCAR's supercomputers
• Some useful GrADS scripts
• Some useful programs for MPI users
• Soundings for idealized simulations
• Pre-configured namelist.input files

Testing and evaluation of CM1

Here are reports on some basic tests of the accuracy and capability of CM1. (Note: all of these tests have been completed, but I haven't had time to write up the results. I plan to have all of these posted online in the near future.)

• Gravity current
• Inertia-gravity waves
• Two-dimensional mountain waves
• Potential flow over a mountain in dry and moist environments
• Bryan-Fritsch moist benchmark
• Large eddy simulation of the convective boundary layer
• A comparison of axisymmetric and three-dimensional simulations of a tropical cyclone

Research Results

Peer-reviewed papers that use CM1:

• Smith, J. W., and P. R. Bannon, 2008:A comparison of compressible and anelastic models of deep dry convection. Mon. Wea. Rev., in press.
• Kang, S.-L., and K. Davis, 2008: The effects of mesoscale surface heterogeneity on the fair-weather convective atmospheric boundary layer. J. Atmos. Sci., in press.
• Schumacher, R. S., and R. H. Johnson, 2008: Mesoscale processes contributing to extreme rainfall in a midlatitude warm-season flash flood. Mon. Wea. Rev., in press.
• Parker, M. D., 2008: Response of simulated squall lines to low-level cooling. J. Atmos. Sci., 65, 1323-1341.
• Edson, A. R., and P. R. Bannon, 2008: Nonlinear atmospheric adjustment to momentum forcing. J. Atmos. Sci., 65, 953-969.
• Bryan, G. H., and R. Rotunno, 2008: Gravity currents in a deep anelastic atmosphere. J. Atmos. Sci., 65, 536-556.
• Kirshbaum, D. J., R. Rotunno, and G. H. Bryan, 2007: The spacing of orographic rainbands triggered by small-scale topography. J. Atmos. Sci., 64, 4222-4245.
• Lin, W. E., L. G. Orf, E. Savory, and C. Novacco, 2007: Proposed large-scale modelling of the transient features of a downburst outflow. Wind & Structures, 10, 315-346.
• Kirshbaum, D. J., G. H. Bryan, R. Rotunno, and D. R. Durran, 2007: The triggering of orographic rainbands by small-scale topography. J. Atmos. Sci., 64, 1530-1549.
• Bryan, G. H., R. Rotunno, and J. M. Fritsch, 2007: Roll circulations in the convective region of a simulated squall line. J. Atmos. Sci., 64, 1249-1266.
• Bannon, P. R., J. M. Chagnon, and R. P. James, 2006: Mass conservation and the anelastic approximation. Mon. Wea. Rev., 134, 2989-3005.
• Bryan, G. H., J. C. Knievel, and M. D. Parker, 2006: A multimodel assessment of RKW Theory's relevance to squall-line characteristics. Mon. Wea. Rev., 134, 2772-2792.
• James, R. P., P. M. Markowski, and J. M. Fritsch, 2006: Bow echo sensitivity to ambient moisture and cold pool strength. Mon. Wea. Rev., 134, 950-964.
• Fanelli, P. F., and P. R. Bannon, 2005: Nonlinear atmospheric adjustment to thermal forcing. J. Atmos. Sci., 62, 4253-4272.
• James, R. P., J. M. Fritsch, and P. M. Markowski, 2005: Environmental distinctions between cellular and slabular convective lines. Mon. Wea. Rev., 133, 2669-2691.
• Bryan, G. H., 2005: Spurious convective organization in simulated squall lines owing to moist absolutely unstable layers. Mon. Wea. Rev., 133, 1978-1997.
• Bryan, G. H., J. C. Wyngaard, and J. M. Fritsch, 2003: Resolution requirements for the simulation of deep moist convection. Mon. Wea. Rev., 131, 2394-2416.
• Bryan, G. H., and J. M. Fritsch, 2002: A benchmark simulation for moist nonhydrostatic numerical models. Mon. Wea. Rev., 130, 2917-2928.

Some recent conference papers that use CM1:

• Wissmeier, U., and R. A. Goler, 2008: The influence of vertical wind shear on deep convection in the tropics. 28th Conference on Hurricanes and Tropical Meteorology, Orlando, FL, Amer. Meteor. Soc.
• Parker, M. D., 2006: Idealized simulations of nocturnal severe wind-producing convective systems. Preprints, 23rd Conf. on Severe Local Storms, St. Louis, MO, Amer. Meteor. Soc., CD-ROM, 6.5.
• Bryan, G. H., and M. L. Weisman, 2006: Mechanisms for the production of severe surface winds in a simulation of an elevated convective system. Preprints, 23rd Conf. on Severe Local Storms, St. Louis, MO, Amer. Meteor. Soc., CD-ROM, 7.5.
• Kirshbaum, D. J., G. H. Bryan, R. Rotunno, and D. Durran, 2005: The response of statically unstable orographic clouds to small-scale topographic features. Preprints, 11th Conf. on Mesoscale Processes, Albuquerque, NM, Amer. Meteor. Soc., CD-ROM, 5M.1.
• Bryan, G. H., and R. Rotunno, 2005: Statistical convergence in simulated moist absolutely unstable laers. Preprints, 11th Conf. on Mesoscale Processes, Albuquerque, NM, Amer. Meteor. Soc., CD-ROM, 1M.6.

Some recent conference abstracts based on work using CM1:

• Bryan, G. H., and R. Rotunno, 2008: The maximum intensity of hurricanes in axisymmetric numerical models. 28th Conference on Hurricanes and Tropical Meteorology, Orlando, FL, Amer. Meteor. Soc.
• Bryan, G. H., and R. Rotunno, 2007: The propagation speed of gravity currents in a deep anelastic atmosphere. 12th Conference on Mesoscale Processes, Waterville Valley, NH, Amer. Meteor. Soc.
• Kirshbaum, D., R. Rotunno, and G. H. Bryan, 2007: The spacing of orographic rainbands triggered by small-scale topography. 12th Conference on Mesoscale Processes, Waterville Valley, NH, Amer. Meteor. Soc.
• Parker, M.D., 2007: Response of simulated squall lines to low-level cooling. 12th Conference on Mesoscale Processes, Waterville Valley, NH, Amer. Meteor. Soc.
• Smith, J. W., and P. R. Bannon, 2007: A comparison of compressible and anelastic models of deep dry convection. 12th Conference on Mesoscale Processes, Waterville Valley, NH, Amer. Meteor. Soc.
• Weisman, M., and G. H. Bryan, 2007: Environmental conditions that are favorable for severe wind production from elevated/nocturnal convective systems. 12th Conference on Mesoscale Processes, Waterville Valley, NH, Amer. Meteor. Soc.
• Orf, L., M. S. Gilmore, R. B. Wilhelmson, J. M. Straka, and E. N. Rasmussen, 2006: The Role of Hook Echo Microbursts in Simulated Tornadic Supercells. Part I Association with counter-rotating vortices and tornadogenesis. 23rd Conf. on Severe Local Storms, St. Louis, MO, Amer. Meteor. Soc.
• M. S. Gilmore, L. Orf, R. B. Wilhelmson, J. M. Straka, and E. N. Rasmussen, 2006: The Role of Hook Echo Microbursts in Simulated Tornadic Supercells. Part II: Sensitivity to Microphysics Parameterization. 23rd Conf. on Severe Local Storms, St. Louis, MO, Amer. Meteor. Soc.
• Bryan, G. H., and M. L. Weisman, 2006: The relative importance of lower-level and upper-level shear on the intensity of squall lines. 23rd Conf. on Severe Local Storms, St. Louis, MO, Amer. Meteor. Soc.
• Bryan, G. H., 2006: The relative importance of lower-level and upper-level shear on the lifting of environmental air by gravity currents. 23rd Conf. on Severe Local Storms, St. Louis, MO, Amer. Meteor. Soc.

Links

• Grid Analysis and Display System (GrADS)
• HDFtools

Send comments and/or questions about this page to:

George H. Bryan
Mesoscale and Microscale Meteorology (MMM) Division
National Center for Atmospheric Research
3450 Mitchell Lane
Boulder, CO 80301, USA
email: gbryan at ucar dot edu

Last updated: 12 August 2008