This page is a supplement to the material presented at the 2008 Fall AGU meeting.
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Abstract
A Study of Pseudo Breakup Events in the Aurora Using Polar/UVI
Higgins, P. A.1, Fillingim, M. O.1, Parks, G. K.1
We have analyzed pseudo breakup events in the aurora using 37 second LBHL Polar/UVI data during the
months of November and December 2007 to study the relationship between breakups and pseudo breakups.
Historically, the distinction between pseudo breakups, which expand locally, and normal breakups,
which expand more globally, has been ill defined. We now present an explicit definition based on
MLat expanse and peak auroral power. Often, the aurora will exhibit a series of pseudo breakup
events before the commencement of a normal breakup. Sometimes a normal breakup does not occur. We
analyze the properties of pseudo breakups and parameters that might make a normal breakup more or
less likely to occur after a series of pseudo breakup events. There is no statistical difference in
MLat location, peak area, peak power dissipation, and total energy deposition for individual pseudo
breakups leading to a normal breakup and those that do not. A normal breakup is likely to occur only
during the first 100 minutes of a sequence of pseudo breakups. However, the total energy (in
electron precipitation) for sequences leading and not leading to a normal breakup is the same,
regardless of the length of the sequence. Although the physical implications of our results are
complicated and unclear, pseudo breakup events should be incorporated in any magnetospheric substorm
model.
1Space Sciences Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720, United States
Contact: phiggins@ssl.berkeley.edu, matt@ssl.berkeley.edu
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Poster
>>A Study of Pseudo Breakup Events in the Aurora Using Polar/UVI
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Data and Events
Events and Parameters Used for Our Study
>>Tabular Data Sheet and Analysis Parameters
Keogram Sheets
(Not all of these events were used in our study.
The groups shown below were not necessarily the
same as those adopted for the study.)
Classic Substorms (clear onset, peak, decay)
>>01
>>02
Not-so-classic breakups (unclear onset, etc...)
>>01
>>02
>>03
>>04
No Breakup Ocurred (series of pseudo breakups fizzling out at the end)
>>01
>>02
All Material is Copyright by: Paul Higgins (UCB/SSL), Matt Fillingim (UCB/SSL), George Parks (UCB/SSL)
Update: September 18, 2008. Space Physics Research Group, University of California at Berkeley