Craig Epifanio

Craig Epifanio

Associate Professor

Mesoscale atmospheric dynamics, topographically forced waves and wakes, numerical modeling and scientific computation

  epifanio@tamu.edu

  (979) 845-9224

  Eller O&M 1017A

Research

My research centers on the basic fluid dynamics of mesoscale atmospheric phenomena, with an emphasis on topographic and thermally forced circulations.  Some topics of current interest include:

  • Topographic waves.  Waves generated by mountain ranges can often break down into turbulence, posing a frequent hazard to aircraft.  One of our current objectives is to better understand this turbulent breakdown process from a theoretical standpoint.  Of particular interest is the physics of topographic wave instability, which is the first step on the route to turbulence.
  • Severe storm dynamics (with Prof. Nowotarski).  The difference between severely tornadic and weakly or non-tornadic supercells often depends on subtle differences in the environment in the lowest levels of the atmosphere.  Our current work uses numerical simulations combined with sophisticated vorticity analysis tools to clarify the dynamics leading to tornadogenesis in some cases, but not others.
  • Computational problems.  Our work often makes heavy use of applied computational methods.  Some methods of current interest include Newton-Krylov solvers for steady-state wave problems, time-splitting schemes for compressible time integration, and the treatment of surface-stress condtions on complex surfaces.

Selected Publications

(* indicates student author)

  • Epifanio, C. C., 2014: Lee vortices.  For inclusion in the Encyclopedia of the Atmospheric Sciences, 2nd edition, Eds. G. North, F. Zhang and J. Pyle, Elsevier.
  • Viner, K. C.*, C. C. Epifanio, and J. D. Doyle, 2013: A steady-state solver and stability calculator for nonlinear internal wave flows. J. Comput. Phys., 251, 432--444. [Science Direct -- Article 24]
  • Qian, T.*, C. C. Epifanio, and F. Zhang, 2012: Topographic effects on the tropical land and sea breeze. J. Atmos. Sci., 69, 130--149.
  • Wang, S.*, F. Zhang, and C. C. Epifanio, 2010: Forced gravity wave response near the jet exit region in a linear model. Q. J. R. Meteorol. Soc., 136, 1773--1787.
  • Qian, T.*, C. C. Epifanio, and F. Zhang, 2009: Linear theory calculations for the sea breeze in a background wind: The equatorial case. J. Atmos. Sci., 66, 1749--1763.
  • Viner, K. C.*, and C. C. Epifanio, 2008: An analysis of Klemp-Wilhelmson schemes as applied to large-scale wave modes. Mon. Wea. Rev., 136, 4730--4745.
  • Epifanio, C. C., and T. Qian*, 2008: Wave-turbulence interactions in a breaking mountain wave. J. Atmos. Sci., 65, 3139--3158.
  • Zhang, F., N. Bei, R. Rotunno, C. Snyder, and C. C. Epifanio, 2007: Mesoscale predictability of moist baroclinic waves: convection-permitting experiments and multistage error growth dynamics. J. Atmos. Sci., 64, 3579--3594.
  • Epifanio, C. C., 2007: A method for imposing surface stress and heat flux conditions in finite-difference models with steep terrain. Mon. Wea. Rev., 135, 906--917.
  • Epifanio, C. C., and R. Rotunno, 2005: The dynamics of orographic wake formation in flows with upstream blocking. J. Atmos. Sci., 62, 3127--3150.
  • Aksoy, A., F. Zhang, J. W. Nielsen-Gammon, and C. C. Epifanio, 2005: Ensemble-based data assimilation for thermally forced circulations. J. Geophys. Res., 110, D16105, doi:10.1029/2004JD005718.
  • Epifanio, C. C., 2003: Lee Vortices. In Encyclopedia of the Atmospheric Sciences, J. Holton, J. Pyle, and J. Curry, editors, Cambridge University Press, 1150--1160.
  • Epifanio, C. C., and D. R. Durran, 2002: Lee-vortex formation in free-slip stratified flow over ridges. Part II: Mechanisms of vorticity and PV production in nonlinear viscous wakes. J. Atmos. Sci., 59, 1166--1181.
  • Epifanio, C. C., and D. R. Durran, 2002: Lee-vortex formation in free-slip stratified flow over ridges. Part I: Comparison of weakly nonlinear inviscid theory and fully nonlinear viscous simulations. J. Atmos. Sci., 59, 1153--1165.
  • Epifanio, C. C., and D. R. Durran, 2001: Three-dimensional effects in high-drag-state flows over long ridges. J. Atmos. Sci., 58, 1051--1065.

Education

Ph.D., Atmospheric Science, University of Washington

B.S., Physics, Williams College

Additional Information

Selected Talks

  • Epifanio, C. C., and K. C. Viner, 2011: Resonant instability in mountain waves:  Breaking at subcritical mountain heights. Presented at the 14th Conference on Mesoscale Processes.
  • Epifanio, C. C., and T. Qian, 2009: Surface stresses and turbulent fluxes:  Problems in mesoscale modeling over terrain. (Seminar)
  • Epifanio, C. C., T. Qian, and F. Zhang, 2009: Linear theory calculations for the sea breeze in a background wind:  The equatorial case. Presented at the 13th Conference on Mesoscale Processes.
  • Epifanio, C. C., and T. Qian, 2007: Wave-turbulence interactions in a breaking mountain wave. Presented at the12th Conference on Mesoscale Processes
  • Epifanio, C. C., D. J. Muraki and Y. Lee, 2006: Unstable wave modes over complex terrain. Presented at the12th Conference on Mountain Meteorology.
  • Epifanio, C. C. and K. C. Viner, 2006: Steep terrain and multiscale flows: Some numerical issues in mesoscale modeling. (Seminar)

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