Seasonal dependence and solar wind control of transpolar arc luminosity

Details Seasonal dependence and solar wind control of transpolar arc luminosity Seasonal dependence and solar wind control of transpolar arc luminosity

Aug 2008

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008jgra..11308316k&link_type=abstract

Journal of Geophysical Research, Volume 113, Issue A8, CiteID A08316

Physics

3

Ionosphere: Auroral Ionosphere (2704), Ionosphere: Polar Cap Ionosphere, Magnetospheric Physics: Auroral Phenomena (2407), Interplanetary Physics: Interplanetary Magnetic Fields, Interplanetary Physics: Solar Wind Plasma

Scientific paper

The influence of the solar wind and the interplanetary magnetic field (IMF) on the luminosity of transpolar arcs (TPAs) is examined by taking into account seasonal effects. The study focuses on those transpolar arcs that appear after an IMF B y sign change during steady northward IMF. It includes 21 northern hemisphere events identified in a previous study from global UV images taken by the Polar spacecraft between 1996 and 2000. Sorting the TPA events by sign of the Earth dipole tilt we find that the TPAs which appear in the dark hemisphere are on average much weaker than TPAs in the sunlit hemisphere. For the dark hemisphere events, no clear correlation between solar wind parameters and TPA luminosity is found. However, in the sunlit hemisphere, a clear dependence on solar wind and IMF conditions is seen. The TPA brightness is strongly influenced by IMF magnitude, northward IMF B z and solar wind speed. A weak, negative correlation with the ion density is found. The TPA luminosity in the sunlit hemisphere is much more strongly controlled by the magnetic energy flux than by the kinetic energy flux of the solar wind. This explains the absence of transpolar arcs for the two B y sign change cases for positive dipole tilts with lowest magnetic energy flux values. The strong influence of the Earth dipole tilt on the transpolar arc luminosity appears due to the dependence of the ionospheric conductivity on solar EUV emissions.

Affiliated with

Also associated with

No associations

Rating

Seasonal dependence and solar wind control of transpolar arc luminosity does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Seasonal dependence and solar wind control of transpolar arc luminosity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Seasonal dependence and solar wind control of transpolar arc luminosity will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1794597