Open AccessWave activity inside hot flow anomaly cavities
Author(s) -
Tjulin A.,
Lucek E. A.,
Dandouras I.
Publication year - 2008
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2008ja013333
Subject(s) - bow shock (aerodynamics) , physics , amplitude , instability , anomaly (physics) , shock wave , plasma , bow wave , solar wind , geophysics , flow (mathematics) , zonal flow (plasma) , mechanics , computational physics , optics , quantum mechanics , tokamak , condensed matter physics
Low‐frequency wave properties inside two hot flow anomalies (HFAs) at different stages of evolution are, for the first time, studied applying the k‐filtering technique on multipoint measurements from the Cluster satellites. The observed wave activity in an HFA cavity in an early stage of its evolution was interpreted as the combination of inherent fluctuation in the solar wind and those of a plasma component specularly reflected at the Earth's bow shock, where the amplitude of the fluctuations had been enhanced by a plasma beam instability. The wave field of a more evolved HFA was found to be less complex but contained a periodicity in the wave number distribution with a period that is suggested to come from the geometry of the HFA cavity.