BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Direct Coupling between the Solar Wind and the Thermosphere - Geor
 ge Siscoe\, Center for Space Physics\, Boston University
DTSTART:20100201T110000Z
DTEND:20100201T120000Z
UID:TALK22976@talks.cam.ac.uk
CONTACT:Tracy Moffat-Griffin
DESCRIPTION:When the sun is in an active state and coronal mass ejections 
 reach the top of their speed of ejection and strength of imbedded magnetic
  field\, encounters with Earth subject the thermosphere to direct magnetic
  coupling to the speeding ejecta with little mediation by the magnetospher
 e.  The force applied to drive thermospheric winds on such occasions is am
 plified (seemingly paradoxically) an order of magnitude over the force tha
 t the solar wind actually exerts.  The situation on such occasions differs
  so markedly from normal that one needs different names to distinguish the
  normal from the disturbed state.  We use “Chapman-Ferraro” and “Dun
 gey-Alfvén\,” respectively\, for reasons that will be made clear.  This
  is a seminar about the Dungey-Alfvén (DA) situation.  The DA state is so
  rare (~1% of time) that its discovery as a distinct state was possible on
 ly with the advent of global numerical simulations\, which allow one to is
 olate it and study it separate from vestiges of the CF state.  One of its 
 distinguishing features\, as mentioned\, is the direct coupling between th
 e solar wind and the thermosphere.  We will focus on this coupling\, prese
 nt its properties as revealed by global simulations\, explain its paradoxi
 cal force\, discuss its consequences for thermospheric research\, and pres
 ent evidence for its existence.
LOCATION:British Antarctic Survey\, Room 187
END:VEVENT
END:VCALENDAR