Abstract
We report on a study of the expected spatial variation of the galactic cosmic-ray intensity in the outer heliosphere, in the vicinity of the solar-wind termination shock. Model simulations which contain all of the transport effects, including drifts, predict that the radial gradients change abruptly at the shock, and that the nature of the effect varies significantly with particle energy. At low energies, the radial gradient changes abruptly from a lower value inside the shock to a higher value outside, whereas at high energies, the higher value of the gradient is inside the shock. This effect, which is a consequence of the matching conditions at the shock and is closely related to diffusive shock acceleration, is qualitatively the same for both helisopheric magnetic polarity states and remains much the same in one-dimensional, two-dimensional, and three-dimensional models. Hence drifts do not change the nature of this phenomenon, although they change it quantitatively. The effect is, of course, not present in the absence of a terminal shock and may prove to be an important diagnostic tool for the study of the termination of the solar wind.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 782-786 |
| Number of pages | 5 |
| Journal | Astrophysical Journal |
| Volume | 405 |
| Issue number | 2 |
| State | Published - Mar 10 1993 |
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Keywords
- Cosmic rays
- Shock waves
- Solar wind
ASJC Scopus subject areas
- Space and Planetary Science
Cite this
The gradient of galactic cosmic rays at the solar-wind termination shock. / Jokipii, J. Randy; Kóta, J.; Merényi, E.
In: Astrophysical Journal, Vol. 405, No. 2, 10.03.1993, p. 782-786.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The gradient of galactic cosmic rays at the solar-wind termination shock
AU - Jokipii, J. Randy
AU - Kóta, J.
AU - Merényi, E.
PY - 1993/3/10
Y1 - 1993/3/10
N2 - We report on a study of the expected spatial variation of the galactic cosmic-ray intensity in the outer heliosphere, in the vicinity of the solar-wind termination shock. Model simulations which contain all of the transport effects, including drifts, predict that the radial gradients change abruptly at the shock, and that the nature of the effect varies significantly with particle energy. At low energies, the radial gradient changes abruptly from a lower value inside the shock to a higher value outside, whereas at high energies, the higher value of the gradient is inside the shock. This effect, which is a consequence of the matching conditions at the shock and is closely related to diffusive shock acceleration, is qualitatively the same for both helisopheric magnetic polarity states and remains much the same in one-dimensional, two-dimensional, and three-dimensional models. Hence drifts do not change the nature of this phenomenon, although they change it quantitatively. The effect is, of course, not present in the absence of a terminal shock and may prove to be an important diagnostic tool for the study of the termination of the solar wind.
AB - We report on a study of the expected spatial variation of the galactic cosmic-ray intensity in the outer heliosphere, in the vicinity of the solar-wind termination shock. Model simulations which contain all of the transport effects, including drifts, predict that the radial gradients change abruptly at the shock, and that the nature of the effect varies significantly with particle energy. At low energies, the radial gradient changes abruptly from a lower value inside the shock to a higher value outside, whereas at high energies, the higher value of the gradient is inside the shock. This effect, which is a consequence of the matching conditions at the shock and is closely related to diffusive shock acceleration, is qualitatively the same for both helisopheric magnetic polarity states and remains much the same in one-dimensional, two-dimensional, and three-dimensional models. Hence drifts do not change the nature of this phenomenon, although they change it quantitatively. The effect is, of course, not present in the absence of a terminal shock and may prove to be an important diagnostic tool for the study of the termination of the solar wind.
KW - Cosmic rays
KW - Shock waves
KW - Solar wind
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M3 - Article
AN - SCOPUS:12044256198
VL - 405
SP - 782
EP - 786
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
ER -