BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:The edge region of the Antarctic stratospheric vortex:  its existe
 nce and its importance. - Dr Howard Roscoe (BAS)
DTSTART:20111207T140000Z
DTEND:20111207T150000Z
UID:TALK34414@talks.cam.ac.uk
CONTACT:Dr Scott Hosking
DESCRIPTION:New evidence conclusively demonstrates the existence of a broa
 d cohesive region of air at the edge of the Antarctic stratospheric vortex
 \, which is only weakly mixed with the core of the vortex.   This new evid
 ence greatly strengthens our earlier work suggesting the existence of this
  edge region of the vortex.  It is from analyses\, ozone measurements and 
 models\, and observed balloon trajectories:\n\n* Calculations of effective
  diffusivity for 2003 and 2005 show similarly weak mixing in the edge regi
 on of the vortex to earlier calculations for 1996.  \n\n* Comprehensive me
 asurements by Antarctic ozonesondes in 2003 show quite different evolution
  in the edge region of the vortex from the vortex core\, in agreement with
  model calculations. \n\n* With one exception\, long duration balloons lau
 nched from Antarctica in spring 2005 remained confined either to the edge 
 region of the vortex or to the vortex core.\n\nThis new evidence again sho
 ws that the edge region is up to half the area of the ozone hole.  The imp
 ortance of the edge region's existence is that because it is unmixed with 
 the vortex core\, it can contain more polar stratospheric clouds as increa
 sed greenhouse gases cool the stratosphere during the 21st Century\, there
 by delaying the expected recovery of the ozone hole.
LOCATION:British Antarctic Survey\, Room 330B
END:VEVENT
END:VCALENDAR