BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4//
BEGIN:VEVENT
UID:20250826T083546EDT-2491TdmhsB@132.216.98.100
DTSTAMP:20250826T123546Z
DESCRIPTION:In this talk\, I will spend some time introducing a few turbule
 nce results that could potentially better our understanding of the atmosph
 ere and oceans. Using those results\, I will try to shed some light on the
  controversial interpretation of the atmospheric energy spectrum. I am mak
 ing a particular effort to keep the presentation as accessible as possible
 \, so students new to the department are particularly welcome! Now\, here'
 s the more technical abstract:\n\nOn near-tropopause turbulence\n\nThe Glo
 bal Atmospheric Sampling Program (GASP) provided data on the horizontal ki
 netic and potential energy spectra near the tropopause. While the steep sy
 noptic-scale part of the energy spectrum agrees well with Charney's theory
  of geostrophic turbulence\, its break to a shallower -5/3 slope in the me
 soscale is still a subject of controversy. \n\nSeveral homogeneous turbule
 nce studies have addressed the issue. In particular\, Bartello (2010) pres
 ented numerical simulations of decaying triply-periodic rotating-stratifie
 d Boussinesq turbulence. It was found that the steep geostrophic spectrum 
 eventually crosses a shallower ageostrophic spectrum at large-enough Rossb
 y numbers. The total energy spectrum  thus exhibits a slope break similar 
 to that observed in the GASP data.\n\nA similar slope break can also occur
  within the quasigeostrophic (QG) framework when vertical boundaries are t
 aken into account (e.g. Tulloch and Smith 2006). In this surface quasigeos
 trophic (SQG) model\, the stratification jump at the tropopause plays a cr
 ucial role in the slope break and ageostrophic motion is ignored. In the h
 omogeneous turbulence model\, it is the other way round. There is thus a n
 eed to reconcile these mutually exclusive perspectives. Numerical simulati
 ons will be presented and discussed.\n
DTSTART:20160921T183000Z
DTEND:20160921T193000Z
LOCATION:Room 934\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue 
 Sherbrooke Ouest
SUMMARY:Student Seminar: Olivier Asselin
URL:/meteo/channels/event/student-seminar-olivier-asse
 lin-262514
END:VEVENT
END:VCALENDAR