BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:The modulational stability and breaking of anelastic internal wave
 s - Bruce Sutherland (Alberta)
DTSTART:20120427T150000Z
DTEND:20120427T160000Z
UID:TALK37674@talks.cam.ac.uk
CONTACT:Dr Ed Brambley
DESCRIPTION:The diagnoses of internal wave propagation\, anelastic growth 
 and breaking in the middle atmosphere are assessed in general circulation 
 models through heuristics based upon observations and the predictions of l
 inear theory.  Before wave breaking occurs\, however\, internal waves grow
  to moderately large amplitude and so the predictions of linear theory are
  drawn into question.  In this talk\, weakly nonlinear theory is used to d
 erive the nonlinear Schrodinger equation\, which reveals that the dominant
  weakly nonlinear dynamics are determined by interactions between internal
  waves and the mean flow that they induce (their "Stokes drift").  In part
 icular\, this predicts that hydrostatic internal waves are modulationally 
 stable\, meaning that their anelastic amplitude growth is retarded as the 
 wavepacket nonlinearly disperses.  Fully nonlinear simulations show\, as a
  consequence\, that hydrostatic waves can overturn tens of kilometers high
 er in the atmosphere than predicted by linear theory.
LOCATION:MR2\, Centre for Mathematical Sciences\, Wilberforce Road\, Cambr
 idge
END:VEVENT
END:VCALENDAR