New

New document: The governing equations for CM1 (Last updated: 16 October 2009)

New: presentation on CM1 parallelization (pdf) (From presentation at NCSA, December 2009)

Code

Download the code here. (Most recent version: cm1r14, uploaded on 23 October 2009)

Documentation

About CM1:

• Acknowledgments.
• Answers to frequently asked questions about CM1.
• Parallel Performance (Last updated: 22 October 2009)
• Original Model Formulation (pdf): chapter from George Bryan's Ph.D. thesis. (applies to cm1r1)

Using CM1:

• A brief summary of how to run cm1.
• CHANGES in release 14 -- new features, modifications, and code fixes for the newest version (23 October 2009)
  • History of all CHANGES (from r2 to present)
• README.namelist -- explains the various settings in the namelist.input file.
• Known bugs (last updated: 23 October 2009)
• 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

CM1 Users:

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

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 articles that use CM1:

• 2010:
• Wang, W., 2010: The influence of topography on single-tower-based carbon flux measurements under unstable conditions: a modeling perspective. Theor. Appl. Climatol., 99, 125-138.
• 2009:
• James, R. P., and P. M. Markowski, 2009: A numerical investigation of the effects of dry air aloft on deep convection. Mon. Wea. Rev., in press.
• Bryan, G. H., and R. Rotunno, 2009: Evaluation of an analytical model for the maximum intensity of tropical cyclones. J. Atmos. Sci., 66, 3042-3060.
• Kirshbaum, D. J., and R. B. Smith, 2009: Orographic precipitation in the tropics: large-eddy simulations and theory. J. Atmos. Sci., 66, 2559-2578.
• Wissmeier, U., and R. Goler, 2009: A comparison of tropical and mid-latitude thunderstorm evolution in response to wind shear. J. Atmos. Sci., 66, 2385-2401.
• Miglietta, M. M., and R. Rotunno, 2009: Numerical simulations of conditionally unstable flows over a mountain ridge. J. Atmos. Sci., 66, 1865-1885.
• Bryan, G. H., and R. Rotunno, 2009: The maximum intensity of tropical cyclones in axisymmetric numerical model simulations. Mon. Wea. Rev., 137, 1770-1789.
• Schumacher, R. S., 2009: Mechanisms for quasi-stationary behavior in simulated heavy-rain-producing convective systems. J. Atmos. Sci., 66, 1543-1568.
• Kang, S.-L., 2009: Temporal oscillations in the convective boundary layer forced by mesoscale surface heat-flux variations. Bound.-Layer Meteor., 132, 59-81.
• Wang, W., 2009: The influence of thermally-induced mesoscale circulations on turbulence statistics over an idealized urban area under a zero background wind. Bound.-Layer Meteor., 131, 403-423.
• 2008:
• Smith, J. W., and P. R. Bannon, 2008:A comparison of compressible and anelastic models of deep dry convection. Mon. Wea. Rev., 136, 4555-4571.
• Kang, S.-L., and K. J. Davis, 2008: The effects of mesoscale surface heterogeneity on the fair-weather convective atmospheric boundary layer. J. Atmos. Sci., 65, 3197-3213.
• Schumacher, R. S., and R. H. Johnson, 2008: Mesoscale processes contributing to extreme rainfall in a midlatitude warm-season flash flood. Mon. Wea. Rev., 136, 3964-3986.
• Wang, W., and K. J. Davis, 2008: A numerical study of the influence of a clearcut on eddy-covariance fluxes of CO2 measured above a forest. Agricultural and Forest Meteor., 148, 1488-1500.
• 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.
• 2007:
• 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.
• 2006:
• 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.
• 2005:
• 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.
• 2003:
• 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.
• 2002:
• 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:

• Letkewicz, C. E., and M. D. Parker, 2009: Mesoscale convective systems crossing the Appalachian Mountains. 13th Conference on Mesoscale Processes, Salt Lake City, UT, Amer. Meteor. Soc., 2.4.
• French, A. J., and M. D. Parker, 2009: The response of simulated nocturnal convective systems to a low-level jet. 13th Conference on Mesoscale Processes, Salt Lake City, UT, Amer. Meteor. Soc., 3.3.
• Bryan, G. H., and R. Rotunno, 2009: The effects of small-scale turbulence on maximum hurricane intensity. 13th Conference on Mesoscale Processes, Salt Lake City, UT, Amer. Meteor. Soc., 14.2.
• Nowotarski, C. J., and P. Markowski, 2008: The effects of varying low-level, environmental stability in low-level rotation in numerical simulations of elevated supercells. 24th Conference on Severe Local Storms, Savannah, GA, Amer. Meteor. Soc., 15.5.
• Orf, L., M. Gilmore, J. Straka, R. Wilhelmson, and E. Rasmussen, 2008: Descending reflectivity cores in a simulated supercell. 24th Conference on Severe Local Storms, Savannah, GA, Amer. Meteor. Soc., 14.2.
• James, R. P., and P. M. Markowski, 2008: A numerical investigation of the effects of dry air aloft on quasi-linear convective systems. 24th Conference on Severe Local Storms, Savannah, GA, Amer. Meteor. Soc., 10.2.
• Bryan, G. H., 2008: Evaluation of the theoretical speed and depth of gravity currents using three-dimensional numerical simulations. 24th Conference on Severe Local Storms, Savannah, GA, Amer. Meteor. Soc., 10.1.

Honors and awards

• 2009: An analysis of a supercell thunderstorm by Leigh Orf of Central Michigan University was selected for the cover of the Coalition for Academic Scientific Computation's 2010 brochure.
• 2008: Casey Letkewicz of the Department of Marine, Earth, and Atmospheric Sciences at North Carolina State University won the Best Student Poster award at the 24th Conference on Severe Local Storms for her studies of simulated mesoscale convective systems crossing the Appalachian Mountains.
• 2008: Chris Nowotarski of the Department of Meteorology at The Pennsylvania State University won the Best Student Oral Presentation award at the 24th Conference on Severe Local Storms for his study of numerically simulated supercells in varying low-level environmental stability.

Links

• Grid Analysis and Display System (GrADS) (supported by Institute of Global Environment and Society)
• NetCDF (supported by Unidata)
• HDFtools (supported by Leigh Orf, Central Michigan University)
• Visualization and Analysis Platform for Ocean, Atmosphere, and Solar Researchers (VAPOR) (supported by the National Center for Atmospheric Research)

Send comments and/or questions about this page to:

George H. Bryan
National Center for Atmospheric Research
3450 Mitchell Lane
Boulder, CO 80301, USA
email: gbryan at ucar dot edu

Last updated: 9 December 2009