Flux closure during magnetotail reconnection
Abstract
The ability to store magnetic energy from the solar wind for later release is a crucial part of magnetotail dynamics. Under which conditions is the magnetotail able to store energy, and how do the subsequent release of energy influence the dynamics in the tail? To address these questions we have studied 13 reconnection event with in-situ Cluster observations from the current sheet and the reconnection region. We find that the most common feature in the current sheet before reconnection onset, is a gradual thinning from 22000 km to 11000 km in about 50 minutes. This thinning seems to occur whether or not there is a total pressure increase or a current sheet stretching in the same time interval. The decrease of the lobe magnetic field during the reconnection events vary between 3~nT and 41~nT, and the magnitude of the unloading increases with about 1.2~nT per unit of the initial lobe magnetic field before reconnection. Furthermore, there is a correlation of 94~% between the decrease of the lobe magnetic field and the estimated decrease of magnetic flux in the magnetotail. We also study how the amount of energy conversion during the 13 reconnection events affect local parameters in the outflow region like velocity, mass and flux transport, particle fluxes and field aligned currents.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFMSM41A1863S
- Keywords:
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- 2723 MAGNETOSPHERIC PHYSICS / Magnetic reconnection;
- 2744 MAGNETOSPHERIC PHYSICS / Magnetotail;
- 2764 MAGNETOSPHERIC PHYSICS / Plasma sheet;
- 2790 MAGNETOSPHERIC PHYSICS / Substorms