Flux transfer events probed by multiple THEMIS spacecraft

Details Flux transfer events probed by multiple THEMIS spacecraft Flux transfer events probed by multiple THEMIS spacecraft

Dec 2008

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008agufmsm51a1632z&link_type=abstract

American Geophysical Union, Fall Meeting 2008, abstract #SM51A-1632

Mathematics

Logic

2723 Magnetic Reconnection (7526, 7835), 2724 Magnetopause And Boundary Layers, 2784 Solar Wind/Magnetosphere Interactions

Scientific paper

Transient bipolar perturbations of the magnetic field normal component are frequently encountered on the dayside magnetopause. Often the field magnitude increases to a peak at the center of the bipolar normal signatures. In the literature such signatures are identified as `flux transfer events' (FTEs). In some cases the field magnitude increase shows a crater-like dimple in the center and is referred to as a `crater FTE'. Behind the phenomenological definitions, there lie two physical interpretations: a typical FTE is a flux rope with strong core field compressed by the curvature force of surrounding twisted fields; a crater FTE represents a flux rope with a weak core field that through the presence of enhanced plasma pressure at the core of the flux rope balances the inward forces deriving from the magnetic tension of the surrounding twisted fields. It has been suggested that the signature of a crater FTE, identified in single spacecraft data, could be mimicked if the spacecraft trajectory passed through a depression on the magnetopause moving from the magnetosphere to the magnetosheath and then back to the magnetosphere. Only observations from multiple spacecraft with appropriately distributed impact parameters can distinguish a passage through a crater FTE from a passage through a perturbed magnetopause. In this study, we survey all the data recorded by multiple THEMIS spacecraft near the dayside magnetopause from May to October in 2007. We find that typical FTEs with central peaks are commonly embedded in depressions of the magnetopause. We also present several crater FTE events in which the flux rope structures with weak core fields are confirmed by multiple THEMIS spacecraft observations. We notice that, in the time interval examined, the crater FTEs are observed much less frequently than typical FTEs. The infrequent encounters with crater FTEs can be understood if they are finite in the axial direction and if non-uniform curvature stress generates field-aligned pressure gradients and associated flow along the axis and out of the flux rope. With this interpretation, the crater FTE would not be a steady structure and it would eventually evolve into a typical one.

Affiliated with

Also associated with

No associations

Rating

Flux transfer events probed by multiple THEMIS spacecraft 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 Flux transfer events probed by multiple THEMIS spacecraft, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Flux transfer events probed by multiple THEMIS spacecraft will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1098872