Steady Magnetospheric Convection Events: A statistical analysis

DeJong, A.D., Clauer, C.R. 


Periods of enhanced magnetospheric convection without substorm signatures have
been called Steady Magnetospheric Convection events (SMC). We have recently
started investigating SMCs under the hypothesis that during these events dayside
and nightside reconnection rates will balance. When this occurs the poleward
auroral boundary, as measured by Polar UVI and IMAGE FUV images, should remain
steady. If the boundary is steady for 3 hours or more and we see no substorm
signatures, then the reconnection rates are fairly well balanced and we have an
SMC. We have used this methodology to pick out SMC during all seasons for 8
years of data (1997-2004). We will use these events to study to solar wind/IMF
driver, Dst, auroral activity, and the balance of reconnection rates. Thus far,
our initial results show that SMCs can occur during many levels of storm time
activity but mostly happen during weaker activity (avg. Dst ~-50). Our solar
wind and IMF drivers concur with past research with an average IMF Bz of -5 nT.
We have also found various degrees of balance between the nightside and dayside
reconnection rates, in that some of our events show a slow loading of the tail,
up to 8 hours, before a substorm occurs. One of our most interesting results is
that not all of our SMCs start and end with substorms.

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Fall Meeting, American Geophysical Union, San Francisco, U.S.A., 
5-9 December 2005