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Oxygen ion response to proton bursty bulk flows
- Publication Year :
- 2016
- Publisher :
- Umeå universitet, Institutionen för fysik, 2016.
-
Abstract
- We have used Cluster spacecraft data from the years 2001 to 2005 to study how oxygen ions respond to bursty bulk flows (BBFs) as identified from proton data. We here define bursty bulk flows as periods of proton perpendicular velocities more than 100 km/s and a peak perpendicular velocity in the structure of more than 200 km/s, observed in a region with plasma beta above 1 in the near-Earth central tail region. We find that during proton BBFs only a minor increase in the O+ velocity is seen. The different behavior of the two ion species is further shown by statistics of H+ and O+ flow also outside BBFs: For perpendicular earthward velocities of H+ above about 100 km/s, the O+ perpendicular velocity is consistently lower, most commonly being a few tens of kilometers per second earthward. In summary, O+ ions in the plasma sheet experience less acceleration than H+ ions and are not fully frozen in to the magnetic field. Therefore, H+ and O+ motion is decoupled, and O+ ions have a slower earthward motion. This is particularly clear during BBFs. This may add further to the increased relative abundance of O+ ions in the plasma sheet during magnetic storms. The data indicate that O+ is typically less accelerated in association with plasma sheet X lines as compared to H+.
- Subjects :
- Physics
010504 meteorology & atmospheric sciences
Proton
Plasma sheet
Plasma
01 natural sciences
Fusion, Plasma and Space Physics
Magnetic field
Ion
Acceleration
Fusion, plasma och rymdfysik
Geophysics
Astronomi, astrofysik och kosmologi
Space and Planetary Science
Physics::Plasma Physics
Beta (plasma physics)
0103 physical sciences
Physics::Space Physics
Perpendicular
Astronomy, Astrophysics and Cosmology
Atomic physics
010303 astronomy & astrophysics
0105 earth and related environmental sciences
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....30d2a899d7d3031d726e3e5252a197e1