Magnetic field dipolarization in the deep inner magnetosphere and its role in development of O+-rich ring current

Details Magnetic field dipolarization in the deep inner magnetosphere and its role in development of O+-rich ring current Magnetic field dipolarization in the deep inner magnetosphere and its role in development of O+-rich ring current

Sep 2010

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010jgra..11500j03n&link_type=abstract

Journal of Geophysical Research, Volume 115, Issue 4, CiteID A00J03

Physics

3

Magnetospheric Physics: Magnetosphere: Inner, Magnetospheric Physics: Substorms, Magnetospheric Physics: Magnetic Storms And Substorms (7954), Magnetospheric Physics: Energetic Particles: Precipitating, Magnetospheric Physics: Magnetosphere/Ionosphere Interactions (2431)

Scientific paper

We studied magnetic field dipolarization and associated ion acceleration in the deep inner magnetosphere, using magnetic field data obtained by the magnetometer on board the Mission Demonstration Satellite 1 (MDS-1) and the energetic neutral atom (ENA) flux data obtained by the high-energy neutral analyzer imager on board the Imager for Magnetopause-to-Aurora Global Exploration satellite. Because the MDS-1 satellite has a geosynchronous transfer orbit, we could survey magnetic field variations at L = 3.0-6.5. Analyzing data in the period from February to July 2002, we found that (1) dipolarization can be detected over a wide range of L (i.e., L = 3.5-6.5, which is far inside the geosynchronous altitude); (2) when the MDS-1 satellite was located close to auroral breakup longitude, the occurrence probability of dipolarization was about 50% just inside the geosynchronous altitude and about 16% at L = 3.5-5.0, suggesting that dipolarization in the deep inner magnetosphere is not unusual; (3) magnetic storms were developing whenever dipolarization was found at L = 3.5-5.0 (4) dipolarization was accompanied by magnetic field fluctuations having a characteristic timescale of 3-5 s, which is comparable to the local gyroperiod of O+ ions; and (5) after dipolarization, the oxygen ENA flux in the nightside ring current region was predominantly enhanced by a factor of 2-5 and stayed at an enhanced level for more than 1 h, while clear enhancement was scarcely seen in the hydrogen ENA flux. From these results, we conjectured a scenario for the generation of an O+-rich ring current, in which preexisting thermal O+ ions in the outer plasmasphere (i.e., an oxygen torus known from satellite observations) experience local and nonadiabatic acceleration by magnetic field fluctuations that accompany dipolarization in the deep inner magnetosphere (L = 3.5-5.0).

Affiliated with

Also associated with

No associations

Rating

Magnetic field dipolarization in the deep inner magnetosphere and its role in development of O+-rich ring current 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 Magnetic field dipolarization in the deep inner magnetosphere and its role in development of O+-rich ring current, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic field dipolarization in the deep inner magnetosphere and its role in development of O+-rich ring current will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1497498