Solar-minimum quiet time ion energization and outflow in dynamic boundary related coordinates

被引:51
作者
Peterson, W. K.
Andersson, L.
Callahan, B. C.
Collin, H. L.
Scudder, J. D.
Yau, A. W.
机构
[1] Univ Colorado, Lab Space & Atmospher Sci, Boulder, CO 80303 USA
[2] Lockheed Martin ATC, ADCS, Palo Alto, CA 94304 USA
[3] Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA
[4] Univ Calgary, Inst Space Res, Dept Phys & Astron, Calgary, AB T2N1N4, Canada
关键词
D O I
10.1029/2008JA013059
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We report hemispheric average fluxes and energies of outflowing energetic (0.015 < E/q < 33 keV) H+, O+, and He+ ions in dynamic boundary-related coordinates, from observations obtained by the Polar/TIMAS instrument near 6000 km altitude in the southern hemisphere during quiet geomagnetic intervals at solar minimum. We discuss our observations in terms of known energization and transport processes. We find that only a small fraction of energetic ions escape from the ionosphere directly into the polar cap and at quiet times the characteristic energies of escaping H+ are between 30 and 300 eV in the cusp region and between 30 eV and 1.2 keV in the midnight sector. For O+ we conclude the characteristic energy in the cusp is similar to 100 eV and between 150 and 600 eV in the midnight sector. Our data suggest that the relative energization and acceleration of O+ is significantly different in the noon quadrant. The observations and analysis presented here also suggest that O+ has activity dependent transport paths from the ionosphere to the ring current that have not previously been identified.
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页数:10
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