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Solar and Space Physics: A Science for a Technological Society
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SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY
9.6.2 Atmosphere and Ionosphere
The past decade has significantly reinforced appreciation of the key influences the ionosphere has
on magnetospheric behavior and of the importance of magnetospheric driving for ionospheric behavior.
It is thus impossible to understand one without taking into account the two-way coupling with the other.
While this decadal survey separates the two regions for ease of discussion, it is clear that they must be
understood as a coupled system. During the coming decade one of the most important emphases of space
physics research will be to clarify quantitatively the coupling of these elements in order to enable progress
toward a predictive understanding of both.
9.6.3 Planetary Science
The magnetospheres of other planets display not only certain close similarities, such as the formation of
bow shocks and radiation belts, but also many processes that are markedly different, such as the source of
charged particles within the radiation belts, which can vary from a mixture of the solar wind and ionosphere
at Earth, to lava volcanoes and water geysers on small moons at Jupiter and Saturn. This rich diversity has
provided surprising discoveries of the breadth of expression of fundamental physical processes that play
important roles in the acceleration of charged particles and the generation of magnetic fields in planetary
magnetospheres. Both planetary and magnetospheric understanding is thus enriched by the comparative
study of magnetospheres. With orbital missions at many of the solar system’s other planets, comparative
magnetospheric studies should increasingly provide insights into the diversity of magnetospheric processes
and how they couple to the planets themselves.
9.6.4 Physics and Astrophysics
Many of the processes and phenomena that determine magnetospheric behavior act throughout the
universe in settings as diverse as laboratory plasmas and supernova shock waves. The ability to observe
and diagnose these processes in situ, with no interference from walls, is a powerful tool to enable basic
understanding with broad applicability. Examples of such processes include magnetic reconnection, shock
acceleration of charged particles, and the physics of rapidly rotating magnetized bodies. Moreover, the
study of comparative magnetospheres not only elucidates the behavior of magnetized planets in our solar
system, but also points the way to the potential breadth of behavior of magnetized bodies throughout the
universe.
9.6.5 Complex Nonlinear System Studies
Eruptive solar processes such as solar flares and spontaneously occurring episodic dynamical variations
in planetary magnetospheres known as magnetic substorms involve highly nonlinear systems. Similarly,
planetary radiation belts evolve through a complicated and nonlinear combination of wave-particle processes that accelerate particles to very high energies, transport them throughout the system, and cause their
loss. Although many of these phenomena are at best poorly understood, their study serves as an important
driver for furthering understanding of the mathematical analysis of complex nonlinear systems. Predicting the behavior of the vast, coupled, multiscale, and nonlinear Sun-magnetosphere-atmosphere system
presents a major challenge to mathematical and computational methods.
Solar and Space Physics: A Science for a Technological Society
260
SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY
9.6.2 Atmosphere and Ionosphere
The past decade has significantly reinforced appreciation of the key influences the ionosphere has
on magnetospheric behavior and of the importance of magnetospheric driving for ionospheric behavior.
It is thus impossible to understand one without taking into account the two-way coupling with the other.
While this decadal survey separates the two regions for ease of discussion, it is clear that they must be
understood as a coupled system. During the coming decade one of the most important emphases of space
physics research will be to clarify quantitatively the coupling of these elements in order to enable progress
toward a predictive understanding of both.
9.6.3 Planetary Science
The magnetospheres of other planets display not only certain close similarities, such as the formation of
bow shocks and radiation belts, but also many processes that are markedly different, such as the source of
charged particles within the radiation belts, which can vary from a mixture of the solar wind and ionosphere
at Earth, to lava volcanoes and water geysers on small moons at Jupiter and Saturn. This rich diversity has
provided surprising discoveries of the breadth of expression of fundamental physical processes that play
important roles in the acceleration of charged particles and the generation of magnetic fields in planetary
magnetospheres. Both planetary and magnetospheric understanding is thus enriched by the comparative
study of magnetospheres. With orbital missions at many of the solar system’s other planets, comparative
magnetospheric studies should increasingly provide insights into the diversity of magnetospheric processes
and how they couple to the planets themselves.
9.6.4 Physics and Astrophysics
Many of the processes and phenomena that determine magnetospheric behavior act throughout the
universe in settings as diverse as laboratory plasmas and supernova shock waves. The ability to observe
and diagnose these processes in situ, with no interference from walls, is a powerful tool to enable basic
understanding with broad applicability. Examples of such processes include magnetic reconnection, shock
acceleration of charged particles, and the physics of rapidly rotating magnetized bodies. Moreover, the
study of comparative magnetospheres not only elucidates the behavior of magnetized planets in our solar
system, but also points the way to the potential breadth of behavior of magnetized bodies throughout the
universe.
9.6.5 Complex Nonlinear System Studies
Eruptive solar processes such as solar flares and spontaneously occurring episodic dynamical variations
in planetary magnetospheres known as magnetic substorms involve highly nonlinear systems. Similarly,
planetary radiation belts evolve through a complicated and nonlinear combination of wave-particle processes that accelerate particles to very high energies, transport them throughout the system, and cause their
loss. Although many of these phenomena are at best poorly understood, their study serves as an important
driver for furthering understanding of the mathematical analysis of complex nonlinear systems. Predicting the behavior of the vast, coupled, multiscale, and nonlinear Sun-magnetosphere-atmosphere system
presents a major challenge to mathematical and computational methods.