Physics
Scientific paper
Oct 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002jgra..107.1299f&link_type=abstract
Journal of Geophysical Research (Space Physics), Volume 107, Issue A10, pp. SMP 14-1, CiteID 1299, DOI 10.1029/2001JA002006
Physics
9
Magnetospheric Physics: Magnetosphere-Inner, Magnetospheric Physics: Ring Current, Magnetospheric Physics: Storms And Substorms, Magnetospheric Physics: Energetic Particles, Trapped
Scientific paper
Ion composition in substorm injections are investigated in detail by using data obtained from the magnetospheric ion composition spectrometer (MICS) on board the Combined Release and Radiation Effects Satellite (CRRES). A total of 398 injection events are identified from 4 February to 10 October, 1991. It is found that the flux enhancements of O+ ions in the ``with-oxygen'' injections (O+ ions occupy more than 20% of the total energy density) are attributed to the flux intensifications of high-energy (E/q >= 100 keV/e) ions. In contrast, the flux of H+ and He++ ions in the ``without-oxygen'' injections (O+ ions are less than 20% total energy density) are enhanced by the intensification of lower energy H+ and He++ (around 50 keV/e) ions. Statistical results also demonstrate that the abundance of O+ ions in an injection strongly depends on the geomagnetic activity. Without-oxygen events take place most probably in relatively weak geomagnetic activity conditions (Dst index is around -50 nT and Kp is around 4). The averaged fractional energy density of O+ ions increases roughly linearly with Kp index. All injections are found to be rich of oxygen ions during the strong magnetic storms (Dst < -100 nT). The present study indicates that the ionospheric oxygen ions are energized more readily during the storm conditions. When the near-Earth reconnection occurs and expands from the central plasma sheet to the plasma sheet boundary layer or even to the lobe region, much more ionosphere origin O+ ions could participate and be energized in the magnetospheric dynamic process. This leads to a with-oxygen injection in the inner magnetosphere. As to the without-oxygen injection, it seems that only preexisting oxygen ions in the near-Earth plasma sheet are accelerated and become a part of the injected ions, thus a rather low abundance of O+ ions can be observed.
Fritz Teresa A.
Fu S. Y.
Pu Zu Yin
Wilken Berend
Zong Qiu Gang
No associations
LandOfFree
Composition signatures in ion injections and its dependence on geomagnetic conditions 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 Composition signatures in ion injections and its dependence on geomagnetic conditions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Composition signatures in ion injections and its dependence on geomagnetic conditions will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1425681