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| Titel |
Effects of cold electron number density variation on whistler-mode wave growth |
| VerfasserIn |
Rongxin Tang, Danny Summers, Xiaohua Deng, Yun He |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250106727
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| Publikation (Nr.) |
 EGU/EGU2015-6407.pdf |
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| Zusammenfassung |
| We examine how the growth of magnetospheric whistler-mode waves depends on the cold
(background) electron number density N0. The analysis is carried out by varying the
cold-plasma parameter a = (electron gyrofrequency)2/(electron plasma frequency)2 which
is proportional to 1/N0. For given values of the thermal anisotropy AT and the ratio Nh/N0,
where Nh is the hot (energetic) electron number density, we find that, as N0 decreases, the
maximum values of the linear and nonlinear growth rates decrease and the threshold wave
amplitude for nonlinear growth increases. Generally, as N0 decreases, the region of
(Nh/N0,AT)-parameter space in which nonlinear wave growth can occur becomes more
limited, i.e., as N0 decreases, the parameter region permitting nonlinear wave growth shifts
to the top-right of (Nh/N0,AT)-space characterized by larger Nh/N0-values and
larger AT-values. The results have implications for choosing input parameters for
full-scale particle simulations and also in the analysis of whistler-mode chorus data. |
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