Details

Autor(en) / Beteiligte

• Hanasz, J.
• de Feraudy, H.
• Schreiber, R.
• Panchenko, M.

Titel

Pulsations of the auroral kilometric radiation

Ist Teil von

• Journal of Geophysical Research - Space Physics, 2006-03, Vol.111 (A3), p.A03209-n/a

Ort / Verlag

Washington, DC: American Geophysical Union

Erscheinungsjahr

2006

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Radio spectrograms derived from Interball‐2/Polrad satellite data have been found to include the signature of a specific type of auroral kilometric radiation (AKR), characterized by 3 to 10 periodic emission intensifications. These occur at frequencies of several mHz, which are well matched with the frequency range of Pc 5 pulsations. From 61 events of pulsating AKR observed by Interball‐2, 39 samples were found to pulsate at nearly the same frequency as field line resonances (FLRs) recorded simultaneously with IMAGE, the ground‐based magnetometer array. The main conclusion drawn from this study is that FLRs are able to drive AKR pulsations. This is confirmed by the observed correlation between the AKR and FLR pulsation frequencies, together with analysis of the AKR source locations. The longitudinal extent of FLR structures, spanning several hours, is inferred from the large distances separating the pulsating AKR source footprints from the ground magnetometer observations. The discussion shows that FLRs are plausible sites for pulsating AKR sources, since their nonlinear evolution can lead to (1) cavity formation by the parallel electric fields of standing inertial Alfvén waves, and (2) the effective transfer of electromagnetic energy from these waves into the acceleration of downflowing electrons, to energies of up to several keV during each half of a pulsation cycle.