Lightning whistlers triggering plasmaspheric hiss: multi-spacecraft observations and ray-tracing analysis

0473459 - ÚFA 2017 FR eng A - Abstrakt
Kolmašová, Ivana - Santolík, Ondřej - Hanzelka, Miroslav - Pickett, J. S. - Kurth, W. S. - Kletzing, C. A.
Lightning whistlers triggering plasmaspheric hiss: multi-spacecraft observations and ray-tracing analysis.
4th Cluster and THEMIS workshop: Book of abstracts. Paris: European Space Agency (ESA), 2017. s. 34-35.
[Cluster-THEMIS Workshop /4./. 07.11.2016-12.11.2016, Palm Springs]
Institucionální podpora: RVO:68378289
Klíčová slova: lightning whistlers * inner magnetosphere * ray-tracing analysis * cluster
Kód oboru RIV: BL - Fyzika plazmatu a výboje v plynech
http://themis.igpp.ucla.edu/events/CLUSTER_THEMIS_2016/Workshop_abstracts_v3.pdf

Series of lightning whistlers were recorded by the Wide-Band Data (WBD)
instruments onboard three Cluster spacecraft (C1, C3, and C4) during the Cluster
Inner Magnetosphere close separation campaign on the 4th of July 2013. Our
dataset is composed of high-resolution waveforms of lightning whistlers which
occurred from 12:00 to 12:10 UT when the spacecraft were moving from the South
to the North close to the equator at RE ~ 3.5. The satellite data were completed by
the WWLLN and EUCLID lightning detection data.
The time-frequency spectrograms of the observed series of lightning whistlers
exhibit two different specific patterns. In the first group of cases we observe intense
bursts of plasmaspheric hiss at frequencies below 2 kHz which are clearly related to
lightning whistlers. No such triggered hiss emissions are observed in the second
group of cases.
Using multi-spacecraft analysis with estimation of the causative lightning stroke
locations we investigate differences in propagation of these two groups of lightning
whistlers. Results of our analysis lead us to a hypothesis that lightning whistlers
penetrating the ionosphere at lower latitudes and propagating unducted may be one
of the sources of plasmaspheric hiss below 2 kHz. We verify this hypothesis using a ray tracing analysis based on the density profile derived from measurements of
Electric and Magnetic Field Instrument Suite and Integrated Science instrument
(EMFISIS) onboard Van Allen Probe spacecraft.
Trvalý link: http://hdl.handle.net/11104/0270577