ATM S 536 - Winter 2010

Weeks 1-2: Tornadic Thunderstorms

Klemp, J., 1987: Dynamics of Tornadic Thunderstorms. Ann. Rev. Fluid Mech., 19, 369-402.
Further reading:
- Weisman, M.L. and J.B. Klemp, 1982: The dependence of numerically simulated convective storms on vertical wind shear and buoyancy. Mon. Wea. Rev., 110, 504-520.
- Trapp, R.J et al., 2007: Changes in severe thunderstorm environment frequency during the 21st century caused by anthropogenically enhanced global radiative forcing. PNAS, 104, 19719–19723.
- Ziegler, C.L. et al., 2001: The Evolution of Low-Level Rotation in the 29 May 1994 Newcastle–Graham, Texas, Storm Complex during VORTEX. Mon. Wea. Rev., 129, 1339-1368.
Figures
- Schematic hodograph and airflow in supercell
- Development of initial rotation
- Storm splitting
- Vertical momentum budget
- Shear induced pressure perturbation in relation to the updraft core
- Mean hodograph for tornadic storms
- Simulated split storms with different low-level wind shear
- Vertical pressure gradients: straight-line hodograph
- Vertical pressure gradients: clockwise turning hodograph
- Inflow along the gust front as rotation intensifies
- Streamwise vorticity feeding the updraft as rotation intensifies

Weeks 3-4: Midlattitude Squall Lines

Weisman, M.L, and R. Rotunno, 2004: `` A theory for strong, long-lived squall lines'' revisited. J. Atmos. Sci., 61, 361-382.
Further reading:
- Stensrud, D., M.C. Coniglio, R.P. Davies Jones, and J.S. Evans, 2005: Comments on ````A theory for strong, long-lived squall lines' revisited'' J. Atmos. Sci., 61, 2989-2996.
- Weisman, M.L, and R. Rotunno, 2005: Reply. J. Atmos. Sci., 61, 2997-3002.
- Emanuel, K., 1983: On assessing local conditional symmetric instability from atmospheric soundings. Mon. Wea. Rev., 111, 2016-2033.
Figures

Weeks 5-6: Mountain waves and momentum transport

Eliassen, A. and E. Palm, 1960: On the transfer of energy in stationary mountain waves. Geofysiske Publikasjoner, 22, 1-23---read pp. 1-11.
Durran, D.R., 2003: Lee waves and mountain waves. Encyclopedia of Atmospheric Sciences. Holton, J.R., J. Pyle and J.A. Curry eds. Elsevier Science Ltd., pp. 1161-1170.
Discussion Paper: Smith, R.B., et al., 2008: Mountain waves entering the stratosphere. J. Atmos. Sci., 65, 2543-2562.
Further reading:
- Smith, R.B., 1979: The influence of mountains on the atmosphere. Advances in Geophysics, 21, 87-229 [our focus is on pp. 88-120].
Figures
- Internal gravity waves forced by a compact oscillator in a basic state at rest (animations).
- Buoyancy and velocity perturbations in a vertically propagating mountain wave.
- Comparison of evanescent and vertically propagating waves over sinusoidal topography.
- Effect of horizontal scale on waves generated by an isolated mountain when N=.01047 and U=20 are constant.
- Vertically propagating wave with cloud over an isolated mountain (schematic).
- Trapped wave with clouds forced by an isolated mountain (schematic).
- Comparison of linear vertically propagating and trapped waves forced by an isolated mountain.
- Comparison of nonlinear vertically propagating and trapped waves forced by an isolated mountain.
- Cirrus generated by a vertically propagating wave over the Sierra Nevada.
- Vertically propagating wave over the Andes.
- Trapped lee waves in Saharan dust.
- Trapped lee waves over Iceland.
- Three-dimensional trapped waves generated by the South Sandwhich Islands.
- Amsterdam Island ship waves.
- Three-dimensional trapped wave forming a flying saucer.
- Comparison of very idealized and slightly idealized breaking waves.
Movies
- Very extensive trapped waves over Nevada (60 MB mov file).

Weeks 7-8: Downslope winds

Durran, D.R., 2003: Downslope winds. Encyclopedia of Atmospheric Sciences. Holton, J.R., J. Pyle and J.A. Curry eds. Elsevier Science Ltd., pp. 1161-1170.
Discussion Paper: Durran, D.R., 1986: Another look at downslope windstorms. Part I: The development of analogs to supercritical flow in an infinitely deep continuously stratified fluid. J. Atmos. Sci., 43, 2527-2543.
Further reading:
- Smith, R.B., 1985: On severe downslope winds. J. Atmos. Sci., 42, 2597-2603.
- Klemp, J.B. and D.K. Lilly, 1975: The dynamics of wave-induced downslope winds. J. Atmos. Sci., 32, 320-339.
Figures
- Surface wind trace near Boulder. Colorado.
- January 11, 1972 aircraft observations near Boulder, Colorado. (Amplification of downslope winds by static stability layering and wave breaking.)
- Bora aircraft observations. (Amplification of downslope winds below a mean-state critical layer)
- Katabatic winds over Terra Nova Bay
- Gliding above the shooting flow
- Amplification of downslope winds through wave breaking. Perturbation horizontal velocity contours; U=10 m/s; Nh/U=0.6 (left) and 1.2 (right).
- Amplification of downslope winds through stability layering. Perturbation horizontal velocity contours; U=10 m/s; Nh/U=0.6 in lower layer and 0.24 above.

Week 9: Lee Vortices

Figures
- Karman vortices generated in water flowing past a cylinder.
- Karman vortex street animation.
- Vortices shed by Cheju Island.
- Vortices shed by Jan Mayen.
- Vortices shed by the Cape Verde Islands.
- Vortices shed by Guadalupe Island.
- Comparison of vortex shedding on two scales.
- Schematic of vortex tiliting.
- Importance of vortex stretching

Week 10: Orographic Precipitation

Discussion paper: Rotunno R. and R. Ferretti, 2001: Mechanisms of Intense Alpine Rainfall. J. Atmos. Sci., 58, 1732-1749.
Figures
- Mechanisms of orographic precipitation. (Houze, 1993: Cloud Dynamics}
- Embedded convection: Hovmoller diagram (Browning et al, 1974: QJRMS, 100, 309-330)
- Embedded convection: vertical cross section (Browning et al, 1974: QJRMS, 100, 309-330)
- Topography around the Bay of Bengal
- Triggering of convection upstream of coastal mountains in the summer monsoon.
- Puget sound convergence zone: surface winds. (Cliff Mass blog)
- Puget sound convergence zone: radar. (Cliff Mass blog)
- Comparison of (A) MM5 and (B) Smith-Barstad precipitation forecasts averaged for 10 major events over the Olympics (Anders et al., 2007: J. Hydrometeorology, 8, 1068-1081)
- Banded orographic convection over the Oregon coast range: radar loop (Kirshbaum et al., 2007: J. Atmos. Sci., 64, 1530-1549)
- Banded orographic convection over the Oregon coast range: simulation loop (Kirshbaum et al., 2007: J. Atmos. Sci., 64, 1530-1549)

Grading: TBA

Mesoscale Dynamics

(still listed as "Mesoscale Storm Structure and Dynamics")