Systematic analysis of occurrence of equatorial noise emissions using 10 years of data from the Cluster mission

0443893 - ÚFA 2016 RIV US eng J - Journal Article
Hrbáčková, Zuzana - Santolík, Ondřej - Němec, F. - Macúšová, Eva - Cornilleau-Wehrlin, N.
Systematic analysis of occurrence of equatorial noise emissions using 10 years of data from the Cluster mission.
Journal of Geophysical Research-Space Physics. Roč. 120, č. 2 (2015), s. 1007-1021. ISSN 2169-9380. E-ISSN 2169-9402
R&D Projects: GA MŠMT LH12231
EU Projects: European Commission(XE) 284520 - MAARBLE
Program: FP7
Institutional support: RVO:68378289
Keywords : equatorial noise * magnetosonic waves * radiation belts * plasmasphere
Subject RIV: BL - Plasma and Gas Discharge Physics
Impact factor: 3.318, year: 2015

We report results of a systematic analysis of equatorial noise (EN) emissions which are also known as fast magnetosonic waves. EN occurs in the vicinity of the geomagnetic equator at frequencies between the local proton cyclotron frequency and the lower hybrid frequency. Our analysis is based on the data collected by the Spatio-Temporal Analysis of Field Fluctuations-Spectrum Analyzer instruments on board the four Cluster spacecraft. The data set covers the period from January 2001 to December 2010. We have developed selection criteria for the visual identification of these emissions, and we have compiled a list of more than 2000 events identified during the analyzed time period. The evolution of the Cluster orbit enables us to investigate a large range of McIlwain's parameter from about L approximate to 1.1 to L approximate to 10. We demonstrate that EN can occur at almost all analyzed L shells. However, the occurrence rate is very low (<6%) at L shells below L=2.5 and above L=8.5. EN mostly occurs between L=3 and L=5.5, and within 7 degrees of the geomagnetic equator, reaching 40% occurrence rate.
Permanent Link: http://hdl.handle.net/11104/0246540