The polar wind and ionospheric outflow
The dynamic outflow of ions from the Earth's polar ionosphere and its consequences in the polar and equatorial regions of the magnetosphere are studied. In the polar region, a physical explanation of how the escape of O{sup +} in the polar wind can become significantly enhanced by O{sup +} heating. A time-dependent hydrodynamic code is developed to model the dynamic polar wind outflow. It was found that the enhance O{sup +} temperatures increase the ion pressure gradient force helping to accelerate O{sup +} scale height. Kinetic processes are examined which could lead to polar wind heating. Results from the observational study reveal that upflowing field-aligned O{sup +} and H{sup +} beams of approximately 10 to 100 eV are a free energy source in the polar cap. The electrostatic stability of the polar wind in the presence of these ion beams is then studied. Depending on the parameters, slow ion acoustic and/or cyclotron modes can be driven unstable. When the O{sup +} beam density is dominant over the H{sup +} by large-amplitude ion cyclotron waves (ICW). First, the ICW decays into daughter electromagnetic and acoustic waves. Second, the acoustic waves heat the H{sup +} in the parallel direction by Landau trapping. Finally, the increase of the parallel velocity enlarges the ICW resonance region resulting in perpendicular heating.
- Research Organization:
- California Univ., Los Angeles, CA (United States)
- OSTI ID:
- 5391827
- Country of Publication:
- United States
- Language:
- English
Similar Records
Driving ionospheric outflows and magnetospheric O+ energy density with Alfvén waves
Physics of heavy ions (1989-1990). Final Report
Related Subjects
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BREMSSTRAHLUNG
CHARGED PARTICLES
CYCLOTRON RADIATION
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTROMAGNETIC RADIATION
ELECTROSTATICS
HEATING
HYDROGEN IONS
ION MOBILITY
IONOSPHERE
IONS
MOBILITY
OXYGEN IONS
PARTICLE MOBILITY
PLANETARY IONOSPHERES
POLAR REGIONS
RADIATIONS
SOUND WAVES
WIND