 |
| Titel |
Negative ions in the auroral mesosphere during a PCA event around sunset |
| VerfasserIn |
C. F. Pozo, E. Turunen, T. Ulich |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 17, no. 6 ; Nr. 17, no. 6, S.782-793 |
| Datensatznummer |
250013776
|
| Publikation (Nr.) |
 copernicus.org/angeo-17-782-1999.pdf |
|
|
|
|
|
| Zusammenfassung |
This is a study of the negative ion chemistry
in the mesosphere above Tromsø using a number of EISCAT observations of high
energy proton precipitation events during the last solar maximum, and in
particular around sunset on 23 October, 1989. In these conditions it is possible
to look at the relative importance of the various photodetachment and
photodissociation processes controlling the concentration of negative ions. The
data analysed are from several UHF GEN11 determinations of the ion-plasma ACF
together with the pseudo zero-lag estimate of the `raw' electron density, at
heights between 55 km and 85 km, at less than 1 km resolution. The power
profiles from the UHF are combined with the 55-ion Sodankylä model to obtain
consistent estimates of the electron density, the negative ion concentrations,
and the average ion mass with height. The neutral concentrations and ion
temperature are given by the MSIS90 model. These parameters are then used to
compare the calculated widths of the ion-line with the GEN11 determinations. The
ion-line spectrum gives information on the effects of negative ions below 70 km
where they are dominant; the spectral width is almost a direct measure of the
relative abundance of negative ions.
Key words. Ionosphere (auroral ionosphere; ion
chemistry and composition; particle precipitation). |
| |
|
| Teil von |
|
|
|
|
|
|
|
|