A Science Strategy for Space Physics (1995) / Chapter Skim
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A Science Strategy for Space Physics: Chapter 2
A Science Strategy for Space Physics: Chapter 2
Pages 47-54
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From page 47... ...
The CHAPTER 5 magnetic fields from coronal holes are carried into interplanetary space by the PART III solar wind. X-ray observations also reveal widespread tiny active regions, called APPENDIX coronal bright points, that may play a role in heating the corona and accelerating the solar wind.
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From page 48... ...
. CMEs are distinct plasma structures in interplanetary space that open and carry out magnetic fields from previously closed regions of the corona.
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From page 49... ...
In some types of solar wind flows the abundances of the elements depend on their first ionization potentials, whereas that effect is less discernible in the wind from coronal holes. The heavy elements are also observed to flow with speeds exceeding the proton speed, indicating the presence of a poorly understood physical mechanism that preferentially accelerates heavy ions relative to protons.
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From page 50... ...
Neutral interstellar atoms are free to stream into the heliosphere where they become ionized and are then carried outward as pickup ions in the solar wind. Acceleration of the pickup ions leads to a population of energetic particles called anomalous cosmic rays, but it remains to be seen how much of the acceleration occurs at the termination shock versus how much occurs upstream of the termination shock, either stochastically or by interplanetary shocks.
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From page 51... ...
What are the properties of the local interstellar medium? CURRENT PROGRAM The principal approach to studying coronal heating and solar wind acceleration is to make coordinated multiwavelength observations at different radial distances along the same streamline, starting from the source region at the solar surface and extending into interplanetary space.
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From page 52... ...
Vigorous coordination of the different heliospheric data sets, with each other and with remote sensing of the solar corona by Yohkoh, Spartan 201, SOHO, and ground-based methods, together with the inclusion of guest investigators with different backgrounds and insights, would greatly enhance the scientific yield. Many of the current and planned studies of the corona not only image its topology, but also provide data from which some properties of the coronal plasma file:///C|/SSB_old_web/strach2.html (6 of 9)
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From page 53... ...
Another approach to surmounting line-of-sight problems is to obtain tomographic, three-dimensional observations of the Sun by remote sensing from two or more solar longitudes. Observations of the solar corona from a longitude ~90¡ from Earth would also allow measurement of the masses and velocities of coronal mass ejections heading Earthward that may cause geomagnetic disturbances a few days later.
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From page 54... ...
A space mission optimized for the study of the outer heliosphere and the interstellar medium, including the plasmas, cosmic rays, and neutral gas, would greatly enhance our understanding of how the heliosphere interacts with its galactic environs. In addition, none of the interplanetary spacecraft mentioned above includes instrumentation for studying phenomena that may depend on the sign of the particle's electric charge.
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