External Triggers of Sawtooth Events Identified by Dayside Convection Changes

Details External Triggers of Sawtooth Events Identified by Dayside Convection Changes External Triggers of Sawtooth Events Identified by Dayside Convection Changes

Dec 2005

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005agufmsm31a0382z&link_type=abstract

American Geophysical Union, Fall Meeting 2005, abstract #SM31A-0382

Other

2720 Energetic Particles: Trapped, 2736 Magnetosphere/Ionosphere Interactions (2431), 2760 Plasma Convection (2463), 2784 Solar Wind/Magnetosphere Interactions, 2788 Magnetic Storms And Substorms (7954)

Scientific paper

Sawtooth events are manifestations of successively occurring substorms during storm time. Energetic particle fluxes at geosynchronous orbit decrease during the growth phase of a substorm and increase at the expansion phase of a substorm. When substorms occur consecutively, the fluxes fluctuate like sawteeth. Solar wind dynamic pressure enhancements during strongly southward IMF and IMF changes which lead to a reduction of convection are two possible triggers of these substorms and thus also of sawtooth flux enhancements. We investigate the frequency of external triggers for sawtooth events based on observations of dayside convection. We use dayside convection observations since onsets of IMF initiated substorms have decreases in dayside convection flow speed, while substorms triggered by dynamic pressure enhancements have increases in dayside convection speed. On the other hand, any events not externally triggered would be expected to not be associated with a change in dayside convection. Events are chosen by the criteria that there is good SuperDARN echo coverage on the dayside. Mid and low latitude H component data are also checked for each substorm event. Dynamic pressure enhancements can cause global H-component increases simultaneously, which is a result of global compression. IMF changes triggered substorm cause increases only on the night side, which results from the substorm current wedge. On the basis of the SuperDARN and H-component data, we suggested that some sawtooth injections are due to dynamic pressure enhancements, some are due to IMF changes, which tend to reduce convection, and others are due to a combination of both. These data are consistent with the general substorm external trigger model.

Affiliated with

Also associated with

No associations

Rating

External Triggers of Sawtooth Events Identified by Dayside Convection Changes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with External Triggers of Sawtooth Events Identified by Dayside Convection Changes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and External Triggers of Sawtooth Events Identified by Dayside Convection Changes will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-762672