Structure and Origin of Magnetic Flux Transport Bursts in the Magnetotail

Monday, 15 December 2014: 8:45 AM
Andrei Runov, University of California Los Angeles, Los Angeles, CA, United States
In situ observations have suggested that magnetic flux
transport in the magnetotail is impulsive with typical pulse duration of 10 to
100 seconds. Multi-point observations, that will be reviewed in this paper,
also have revealed that the flux transport pulses are spatial structures moving
at a velocity of 100 to 500 km/s. That corresponds to a spatial scale of the
pulses of 2 to 5 Earth's radii (RE). It has been established that the flux
transport is localized in cross-tail direction within a 1 to 3 RE-wide channels
and dominantly observed in the premidnight magnetotail sector. A concept of
impulsive (time-dependent) magnetic reconnection may explain the short-time flux
transfer pulses. It is unknown, however, what determines the characteristic time
scale of the pulses and spatial localization of the flux transport channels. A
role of Rayleigh-Taylor-type and drift instabilities in structuring and
localization of the flux bursts is another open question.