ISSN:
1572-9672
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The detailed knowledge of the distribution of neutral interstellar hydrogen in the interplanetary space is necessary for a reliable interpretation of optical and H+ pickup ions observations. In the paper, we review the status of the modelling efforts with the emphasis on recent improvements in that field. We discuss in particular the role of the nonstationary, solar cycle-related effects and the consequences of hydrogen filtration through the heliospheric interface region for its distribution in the inner Solar System. We demonstrate also that the use of the simple ‘cold’ model, neglecting the thermal character of the hydrogen gas (T ∼ 8000 K), is generally incorrect for the whole region of the inner heliosphere (R 〈 5 AU) since it leads to a substantial underestimation of the local hydrogen density and thus influences the derivation of the H properties in the outer heliosphere/LISM. Referring to recent Ulysses measurements, we point out also the need to consider in the modelling the effects of the latitudinal asymmetry of the ionization rate.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00170813
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