A Science Strategy for Space Physics (1995) / Chapter Skim
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A Science Strategy for Space Physics: Summary
A Science Strategy for Space Physics: Summary
Pages 9-19
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From page 9... ...
It has become a "hard" science, focusing on understanding the fundamental interactions between charged particles, electromagnetic fields, and gases in the natural laboratory consisting of the galaxy, the Sun, the heliosphere, and planetary magnetospheres, ionospheres, and upper atmospheres. The motivation for space physics research goes far beyond basic physics and intellectual curiosity, however, because long-term variations in the brightness of the Sun vitally affect the habitability of the Earth, while sudden rearrangements of magnetic fields above the solar surface can have profound effects on the delicate balance of the forces that shape our environment in space and on the human technology that is sensitive to that balance.
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From page 10... ...
Box 1 The Key Topics in Space Physics Research q Mechanisms of solar variability q The physics of the solar wind and the heliosphere q The structure and dynamics of magnetospheres and their coupling to adjacent regions q The middle and upper atmospheres and their coupling to regions above and below q Plasma processes that accelerate very energetic particles and control their propagation THE KEY TOPICS IN SPACE PHYSICS RESEARCH Mechanisms of Solar Variability file:///C|/SSB_old_web/strasum.html (2 of 12)
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From page 11... ...
, when few sunspots appeared on the solar surface for roughly 70 years, with the Little Ice Age, when Europe experienced exceptionally cold winters, has potentially serious implications for society should a similar episode occur under current conditions. In addition, confidence in current understanding of the solar interior was upset by the discordantly low flux of solar neutrinos observed in several experiments.
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From page 12... ...
Further observations and numerical simulations are required to determine the relative importance of magnetic reconnection, explosive jets, tiny active regions called bright points, hydromagnetic waves, and the topology of the magnetic fields in the corona in accelerating the quasi-stationary solar wind. There are additional questions about the acceleration of the nonstationary or transient solar wind arising from explosive events called coronal mass ejections.
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From page 13... ...
Carry out stereo imaging of the solar corona to reveal the three dimensional structure of coronal features without the ambiguity caused by integration along the line of sight. Develop and use techniques for the remote sensing of the coronal magnetic field in order to improve knowledge of the acceleration of the solar wind and of the initiation of coronal mass ejections.
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From page 14... ...
Simultaneously image the plasma and energetic particle populations in the aurora, plasmasphere, ring current, and inner plasma sheet to study the global structure and large-scale interactions of magnetospheric and ionospheric regions during different levels of solar and geomagnetic activity. Maintain the full complement of particle and field instruments on current and future planetary missions to gain increased understanding of the formation and dynamics of diverse magnetospheres and ionospheres.
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From page 15... ...
Highly variable electric fields and currents originating above and below the upper atmosphere are major sources of energy and momentum to that region. Gravity, planetary, and tidal waves that originate partly from the lower atmosphere grow in amplitude as they propagate upward, where they contribute to the momentum and energy budgets of the middle and upper atmospheres and produce turbulence that influences mixing processes.
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From page 16... ...
Take advantage of opportunities to include carefully chosen, appropriate instruments on planetary orbiter missions to make measurements critical to understanding planetary aeronomy and its relation to terrestrial aeronomic processes. Plasma Processes That Accelerate Very Energetic Particles and Control Their Propagation Many of the plasma processes responsible for phenomena within the heliosphere probably also play a role in determining the properties of galactic cosmic rays, which are the only available sample of matter from outside the local solar neighborhood.
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From page 17... ...
Measure isotope abundances for nuclei heavier than nickel and elemental abundances through the actinides to probe the plasma regions where the nuclei are synthesized and to measure the time scales involved. RECOMMENDED RESEARCH EMPHASES The specific programs required to obtain answers to the questions raised under each of the five key topics outlined above are quite different.
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From page 18... ...
Much technology is already in place to take the next observational steps required to address many of the important questions in space physics outlined here. These steps include: Adapting existing instrumentation to the new generation of smaller spacecraft and more focused space missions; Placing space physics instruments on planetary, Department of Defense, and other spacecraft of opportunity; Utilizing suborbital platforms such as rockets and long-duration balloons for both science objectives and instrument development; and Supporting, where appropriate, activities at unique ground sites such as in the polar cap.
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From page 19... ...
Special emphasis should be given to the following topics: Recognizing that synergy between observations, modeling, and theory provides the optimum way of addressing the principal questions in space physics; Making numerical simulations of space physics systems more realistic by extending them to three dimensions, longer time durations, and a greater range of scale sizes, and by incorporating additional physical and chemical processes; Ensuring access to state-of-the-art computational facilities; Exploiting new insights gained from theory, especially the theory of nonlinear processes; and Revisiting earlier efforts to predict solar activity, such as coronal mass ejections and flares, using simulations combined with solar observations. 1A glossary of acronyms is included as the appendix, and the principal programs identified by the acronyms are described in the main text.
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