Magnetospheric Multiscale analysis of intense field-aligned Poynting flux near the Earth's plasma sheet boundary

• The Magnetospheric Multiscale mission is employed to examine intense Poynting flux directed along the background magnetic field toward Earth, which reaches amplitudes of nearly 2 mW/m(2). The event is located within the plasma sheet but likely near the boundary at a geocentric distance of 9 RE in association with bulk flow signatures. The fluctuations have wavelengths perpendicular to the magnetic field of 124-264 km (compared to an ion gyroradius of 280 km), consistent with highly kinetic Alfven waves. While the wave vector remains highly perpendicular to the magnetic field, there is substantial variation of the direction in the perpendicular plane. The field-aligned Poynting flux may be associated with kinetic Alfven waves released along the separatrix by magnetotail reconnection and/or the radiation of waves excited by bursty bulk flow braking and may provide a means through which energy released by magnetic reconnection is transferred to the auroral region.

Subject headings

Natural Sciences  (hsv)

Earth and Related Environmental Sciences  (hsv)

Geology  (hsv)

Naturvetenskap  (hsv)

Geovetenskap och miljövetenskap  (hsv)

Geologi  (hsv)

Keyword

High-Speed Flows; Alfven Waves; R-E; Layer; Tail; Acceleration; Spacecraft; Aurora; Polar; Power