EMIC triggered emissions: what do we learn from ray-tracing results?

0429247 - ÚFA 2015 eng A - Abstrakt
Grison, Benjamin - Masson, A. - Santolík, Ondřej
EMIC triggered emissions: what do we learn from ray-tracing results?
Cluster 23rd Workshop : Tromsø, Norway : 16-20 September 2013 : Abstract Book. 2013.
[Cluster Workshop /23./. 16.09.2013-20.09.2013, Tromso]
Institucionální podpora: RVO:68378289
Kód oboru RIV: BL - Fyzika plazmatu a výboje v plynech
http://caa.estec.esa.int/images/cluster_workshops/23/Cluster23_abstract_book_v2.1.pdf

EMIC triggered emissions have been reported in the inner magnetosphere at the edge of the nightside plasmapause [Pickett et al., 2010]. The generation mechanism proposed by Omura et al. [2010] is very similar to the one of the whistler chorus emissions. Corresponding simulation results agree with observations and theory [Shoji and Omura, 2011]. The main characteristics of these emissions generated in the magnetic equatorial plane region are a frequency with time dispersion and a high level of coherence.We present here a Cluster case study, on the 19th of March 2001 at 10:00 UT when EMIC triggered emissions are observed by the four spacecraft. At that time the fleet was close to the nightside plasmapause at a magnetic latitude of about 10-­‐15 degrees. From single spacecraft measurements we can estimate the polarization properties of these waves by combining STAFF and FGM data: the wave vector is almost perpendicular to B and it displays a right-­‐hand circular polarization. Adding the EFW data, we show that the Poynting vector is directed mainly toward the Earth. The fleet configuration enables us to confirm this sense of propagation by a multi-­‐spacecraft analysis.This work is dedicated to ray tracing analysis. We use the spacecraft position, the wave vector orientation and the frequency of the emissions and the usual parameters for Tsyganenko models as input data for the model. From the ray tracing results we estimate the position and the size of the source region. We also compare the observed propagation velocity to the estimated one. We finally compare the inferred source region location to the 29 predicted one. The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7–SPACE–2010–1) under grant agreement n. 284520 (MAARBLE).
Trvalý link: http://hdl.handle.net/11104/0234383