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SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY
9.1.3 Space Weather
12. Encourage the creation of a complete architecture for the National Space Weather Program that
would coordinate joint research, commercial, and operational space weather observations and define
agency roles for producing, distributing, and forecasting space weather products. In addition the SWMI
panel encourages all agencies to foster interactions between the research and operational communities
and to identify funding for maintaining a healthy research-to-operations/operations-to-research program.
13. Implement a program to determine, based on past observations, the optimum set of measurements
that are required to drive high-fidelity predictive models of the environment.
Implementation of these imperatives will enable achievement of the exciting and high-priority science
goals laid out in this report, providing a strong foundation for the accomplishment of the long-term actions
described earlier in this decadal survey. To summarize, eight overarching SWMI science goals motivate
sixteen prioritized, actionable imperatives that are required to enable the goals (these prioritized imperatives and their mapping to decadal categories from Part I are shown in Table 9.4 at the end of this chapter).
9.2 INTRODUCTION TO SWMI SCIENCE
This section gives a brief introduction to the magnetosphere and its interactions with the solar wind
and the upper atmosphere. This information provides a context for the subsequent discussion of the past
decade’s accomplishments and important unanswered questions, leading to the SWMI panel’s science
goals for the coming decade and the initiatives necessary to accomplish them.
9.2.1 What Is the Magnetosphere?
The magnetosphere (Figure 9.1) is a vast, highly coupled system governed by fundamental physical
processes and characterized by complex, nonlinear linkages between its different parts. It is formed by the
interaction of the solar wind plasma stream and its embedded magnetic field with Earth’s intrinsic magnetic
field. Earth with its field is an obstacle in the solar wind flow, carving out a separate plasma domain where
Earth’s field has dominant control over the motions of the electrically charged particles trapped there. These
charged particles come from both the solar wind and Earth’s upper atmosphere. This region of dominance,
the magnetosphere, extends out to approximately 10 Earth radii on the sunward side of Earth and, in a
long “magnetotail,” extends to well beyond the Moon on the side away from the Sun. The shape of the
magnetosphere is determined by the balance between the pressure exerted by the solar wind plasma and
interplanetary magnetic field (IMF) and the pressure of Earth’s plasma and magnetic field. Earth is only one
of six of the Sun’s planets (Mercury, Earth, Jupiter, Saturn, Uranus, and Neptune) that are known to have a
magnetosphere by virtue of their intrinsic magnetic fields. Ganymede, one of Jupiter’s satellites, also has
its own tiny magnetosphere embedded within Jupiter’s giant one.
9.2.1.1 Regions
The magnetosphere is made up of regions with different plasma characteristics. As illustrated in
Figure 9.1, the shape of the underlying geomagnetic field lines governs the morphology of these various
regions. Nearest Earth, there is a relatively cold and dense region called the plasmasphere. The plasmasphere contains plasma that has escaped from the ionosphere, the ionized region of Earth’s upper atmosphere. Coincident with the plasmasphere or residing at slightly larger radial distances are higher-energy
charged-particle populations called the ring current and radiation belts. Ring-current particles drift azi-
Solar and Space Physics: A Science for a Technological Society
212
SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY
9.1.3 Space Weather
12. Encourage the creation of a complete architecture for the National Space Weather Program that
would coordinate joint research, commercial, and operational space weather observations and define
agency roles for producing, distributing, and forecasting space weather products. In addition the SWMI
panel encourages all agencies to foster interactions between the research and operational communities
and to identify funding for maintaining a healthy research-to-operations/operations-to-research program.
13. Implement a program to determine, based on past observations, the optimum set of measurements
that are required to drive high-fidelity predictive models of the environment.
Implementation of these imperatives will enable achievement of the exciting and high-priority science
goals laid out in this report, providing a strong foundation for the accomplishment of the long-term actions
described earlier in this decadal survey. To summarize, eight overarching SWMI science goals motivate
sixteen prioritized, actionable imperatives that are required to enable the goals (these prioritized imperatives and their mapping to decadal categories from Part I are shown in Table 9.4 at the end of this chapter).
9.2 INTRODUCTION TO SWMI SCIENCE
This section gives a brief introduction to the magnetosphere and its interactions with the solar wind
and the upper atmosphere. This information provides a context for the subsequent discussion of the past
decade’s accomplishments and important unanswered questions, leading to the SWMI panel’s science
goals for the coming decade and the initiatives necessary to accomplish them.
9.2.1 What Is the Magnetosphere?
The magnetosphere (Figure 9.1) is a vast, highly coupled system governed by fundamental physical
processes and characterized by complex, nonlinear linkages between its different parts. It is formed by the
interaction of the solar wind plasma stream and its embedded magnetic field with Earth’s intrinsic magnetic
field. Earth with its field is an obstacle in the solar wind flow, carving out a separate plasma domain where
Earth’s field has dominant control over the motions of the electrically charged particles trapped there. These
charged particles come from both the solar wind and Earth’s upper atmosphere. This region of dominance,
the magnetosphere, extends out to approximately 10 Earth radii on the sunward side of Earth and, in a
long “magnetotail,” extends to well beyond the Moon on the side away from the Sun. The shape of the
magnetosphere is determined by the balance between the pressure exerted by the solar wind plasma and
interplanetary magnetic field (IMF) and the pressure of Earth’s plasma and magnetic field. Earth is only one
of six of the Sun’s planets (Mercury, Earth, Jupiter, Saturn, Uranus, and Neptune) that are known to have a
magnetosphere by virtue of their intrinsic magnetic fields. Ganymede, one of Jupiter’s satellites, also has
its own tiny magnetosphere embedded within Jupiter’s giant one.
9.2.1.1 Regions
The magnetosphere is made up of regions with different plasma characteristics. As illustrated in
Figure 9.1, the shape of the underlying geomagnetic field lines governs the morphology of these various
regions. Nearest Earth, there is a relatively cold and dense region called the plasmasphere. The plasmasphere contains plasma that has escaped from the ionosphere, the ionized region of Earth’s upper atmosphere. Coincident with the plasmasphere or residing at slightly larger radial distances are higher-energy
charged-particle populations called the ring current and radiation belts. Ring-current particles drift azi-