 |
| Titel |
Magnetospheric Line Radiation: Survey results using 6.5 years of DEMETER spacecraft data |
| VerfasserIn |
Barbora Bezdekova, Frantisek Nemec, Michel Parrot, Ondrej Santolik, Oksana Kruparova |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250104470
|
| Publikation (Nr.) |
 EGU/EGU2015-3889.pdf |
|
|
|
|
|
| Zusammenfassung |
| Frequency-time spectrograms of electromagnetic emissions observed in the Earth’s inner
magnetosphere at frequencies between about 1 and 8 kHz sometimes consist of
several nearly horizontal and almost equidistant intense lines. The emissions of this
type were observed both by ground-based instruments and by satellites, and they
are usually called Magnetospheric Line Radiation (MLR). We compiled a list of
all MLR events observed by the low-altitude DEMETER spacecraft during the
duration of the mission (2004–2010). Altogether, 1230 MLR events were identified,
which likely represents the largest database available to date. We analyze a possible
connection between the MLR occurrence and solar wind parameters using the superposed
epoch analysis. We show that the MLR occurrence is enhanced during specific solar
wind parameters, being larger in relation to the interplanetary shocks. We further
show that there is a connection between the MLR occurrence and the season of the
year, with the events being more frequent during the northern winter than during
the northern summer. As for the spatial distribution of the event occurrence, the
events are less frequent at geomagnetic longitudes of the South Atlantic Anomaly.
We also analyze the energy spectra of electrons precipitating at the times of MLR
events, and we derive energy-latitude plot of electron flux enhancements related to
the MLR occurrence. Finally, we perform a detailed wave analysis of two MLR
events for which high resolution multicomponent data are available. It is found
that the events are right-handed nearly circularly polarized, propagating at oblique
wave normal angles from larger radial distances and lower geomagnetic latitudes. |
|
|
|
|
|
|