Copyright © National Academy of Sciences. All rights reserved.
Solar and Space Physics: A Science for a Technological Society
222
SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY
Coordinated studies employing imaging, remote sensing, modeling, and local measurements have
demonstrated the critical importance of hot-cold plasma interactions. Imaging revealed the dynamics of
ring-current-plasmasphere overlap (see Figure 9.6) and helped confirm the prediction that growth of ion
cyclotron waves in this region can cause scattering losses of both energetic ions and radiation-belt electrons. Theoretical predictions that absence of cold dense plasma facilitates the acceleration of energetic
electrons to relativistic energies were confirmed by observations. Studies showed that cold, dense plasma
plays a pivotal role in defining the wave environment that controls energetic particle behavior, overturning
the decades-old idea of a passive, quiescent plasmasphere in favor of an extremely dynamic, influential
one. Other aspects of this influence included partial quenching of dayside magnetopause reconnection
by plasmaspheric plumes and the creation of ionospheric density enhancements that refract and scintillate
GPS signals, producing ranging errors of tens of meters.
It is clear that much progress has been made in understanding the system-level dynamics of the inner
magnetosphere. In the coming decade, this knowledge must be refined and extended to encompass the
entire magnetosphere-ionosphere-thermosphere system.
FIGURE 9.6 The past decade produced a new understanding of the system-level dynamics and mutual interaction of the
plasmasphere (cold plasma) and ring current (warm plasma). Plasmaspheric images from the IMAGE satellite (in green,
above) revealed coherent plume structure and plasmapause distortions from time-varying electric fields. IMAGE ENA
images (orange, above) show the partial ring current whose pressure distorts the solar wind forcing field that erodes the
plasmasphere. SOURCE: Adapted from J. Goldstein, B.R. Sandel, M.F. Thomsen, M. Spasojević, and P.H. Reiff, Simultaneous
remote-sensing and in situ observations of plasmaspheric drainage plumes, Journal of Geophysical Research 109:A03202,
doi:10.1029/2003JA010281, 2004. Copyright 2004 American Geophysical Union. Reproduced by permission of American
Geophysical Union.
14:06 26 June 2000
Plume
Plume
3:01 27 June 2000
Global Imaging Measurements
Plasmasphere
Ring Current
Local Density Measurements
Figure 9-6
Solar and Space Physics: A Science for a Technological Society
222
SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY
Coordinated studies employing imaging, remote sensing, modeling, and local measurements have
demonstrated the critical importance of hot-cold plasma interactions. Imaging revealed the dynamics of
ring-current-plasmasphere overlap (see Figure 9.6) and helped confirm the prediction that growth of ion
cyclotron waves in this region can cause scattering losses of both energetic ions and radiation-belt electrons. Theoretical predictions that absence of cold dense plasma facilitates the acceleration of energetic
electrons to relativistic energies were confirmed by observations. Studies showed that cold, dense plasma
plays a pivotal role in defining the wave environment that controls energetic particle behavior, overturning
the decades-old idea of a passive, quiescent plasmasphere in favor of an extremely dynamic, influential
one. Other aspects of this influence included partial quenching of dayside magnetopause reconnection
by plasmaspheric plumes and the creation of ionospheric density enhancements that refract and scintillate
GPS signals, producing ranging errors of tens of meters.
It is clear that much progress has been made in understanding the system-level dynamics of the inner
magnetosphere. In the coming decade, this knowledge must be refined and extended to encompass the
entire magnetosphere-ionosphere-thermosphere system.
FIGURE 9.6 The past decade produced a new understanding of the system-level dynamics and mutual interaction of the
plasmasphere (cold plasma) and ring current (warm plasma). Plasmaspheric images from the IMAGE satellite (in green,
above) revealed coherent plume structure and plasmapause distortions from time-varying electric fields. IMAGE ENA
images (orange, above) show the partial ring current whose pressure distorts the solar wind forcing field that erodes the
plasmasphere. SOURCE: Adapted from J. Goldstein, B.R. Sandel, M.F. Thomsen, M. Spasojević, and P.H. Reiff, Simultaneous
remote-sensing and in situ observations of plasmaspheric drainage plumes, Journal of Geophysical Research 109:A03202,
doi:10.1029/2003JA010281, 2004. Copyright 2004 American Geophysical Union. Reproduced by permission of American
Geophysical Union.
14:06 26 June 2000
Plume
Plume
3:01 27 June 2000
Global Imaging Measurements
Plasmasphere
Ring Current
Local Density Measurements
Figure 9-6