Inhomogeneous transverse electric fields and wave generation in the auroral region : A statistical study

• We use data from the Freja satellite to investigate the importance of localized transverse DC electric fields for the generation of broadband waves responsible for ion heating in the auroral region. Theoretical models indicate that shear in the plasma Row perpendicular to the geomagnetic field can generate waves in a broad range around the ion gyrofrequency for parallel currents significantly below the threshold of the current-driven electrostatic ion cyclotron instability. We compare in situ data with laboratory measurements and theoretical predictions, and we find that inhomogeneous electric fields might well be important for the generation of waves in the auroral region.

Ämnesord

NATURVETENSKAP  -- Fysik -- Fusion, plasma och rymdfysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Fusion, Plasma and Space Physics (hsv//eng)

Nyckelord

ion-cyclotron turbulence

band elf waves

velocity-shear

magnetic-field

electrostatic-waves

energization mechanisms

topside ionosphere

aligned currents

plasma-waves

flow

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)