BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Use of the semi-geostrophic model in understanding large-scale atm
 osphere and ocean flows - Cullen\, M (Met Office)
DTSTART:20131205T091500Z
DTEND:20131205T101500Z
UID:TALK49211@talks.cam.ac.uk
CONTACT:Mustapha Amrani
DESCRIPTION:The semi-geostrophic model is an accurate approximation to the
  Navier-Stokes equations when the Lagrangian Rossby number is small and th
 e aspect ratio is less than f/N (where f is the Coriolis parameter and N t
 he Brunt-Vaisala frequency). In practice this leads to a horizontal scale 
 of around 1000km in the atmosphere and 100km in the ocean. The approximati
 on is second order accurate in the limit epsilon tends to zero where the R
 ossby number is O(epsilon) and the Froude number O(sqrt(epsilon)). This ap
 proximation has a big advantage over the quasi-geostrophic approximation b
 ecause it allow O(1) variations of the static stability\, Coriolis paramet
 er and orographic height. These features are essential in describing large
 -scale flows. The stability of the solutions of this system is consistent 
 with the observed persistence of large-scale anomalies in the atmosphere a
 nd ocean. The failure of the approximation on smaller scales is associated
  with the lack of such structures on smal ler scales in the observed syste
 m. The talk will demonstrate how the semi-geostrophic model can be used to
  validate numerical methods\, and how it can be extended to include a  rea
 listic model of the atmospheric boundary layer.\n
LOCATION:Seminar Room 1\, Newton Institute
END:VEVENT
END:VCALENDAR