Estimates of magnetotail reconnection rate based on IMAGE FUV and EISCAT measurements

Ostgaard, N., Moen, J., Mende, S.B., Frey, H.U., Immel, T.J., Gallop, P., Oksavik, K. 


Dayside reconnection between the interplanetary and the terrestrial magnetic field couples the
solar wind electric field to the Earth's magnetosphere, increases the magnetospheric convection
and results in efficient transport of solar wind energy into the magnetosphere. Subsequent
reconnection of the lobe magnetic field transports energy into the closed magnetic field region.
Combining global imaging and ground based radar measurements we estimate the reconnection
rate in the magnetotail during a substorm event that occurred November 28, 2000. Global images
from the IMAGE FUV system guide us to identify ionospheric signatures of the open-closed field
line boundary observed by EISCAT VHF. Continuous radar and optical monitoring of the
open-closed field line boundary are used to determine the location and velocity of the open-closed
boundary and the ion flow velocity normal to this boundary. Estimates of the reconnection electric
field in the ionosphere are compared with variations in the auroral intensity and the solar wind
electric field. 
		   
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Fall 2002 Meeting of the American Geophysical Union
San Francisco, CA, USA, 6-10 December 2002