Flux Transfer events (FTE)

spaceweb@oulu.fi - last update: 9 May 1998, 2010 UT (RR)

Flux transfer events (FTE) are thought to be patchy (spatially and temporally limited) reconnection events occurring in the dayside magnetopause. They were first discovered by Russell and Elphic (1978) and Haerendel et al. (1978), who studied the magnetic field measurements in boundary normal coordinates near the magnetopause, and found bipolar signatures in the Bn component (outward along the boundary normal): first outward and then inward (normal FTE) or the other way around (reverse FTE). The occurrence frequency of these signatures is about 8 minutes (Russell et al., 1996). For a recent statistical study, see Sanny et al. (1998).

One of the most interesting aspects of FTEs are their signatures on ground: they are still not known for sure (e.g., Glassmeier and Stellmacher, 1996). Number of possibilities exist:

flow bursts
auroral transients
magnetic field transients
damped ULF wave packets

One important point is that different source mechanisms can generate similar ground-based signatures, especially in magnetometer measurements. For example, travelling magnetospheric convection vortices (TCV) have been shown to be related with solar wind pressure pulses.

References

Glassmeier, K.-H. and M. Stellmacher, Mapping flux transfer events to the ionosphere, Adv. Space Res., 18, (8)151-(8)160, 1996.
Russell, C. T. and R. C. Elphic, Initial ISEE magnetometer results: magnetopause observations, Space Sci. Rev., 22, 681-, 1978.
Haerendel, G., G. Pachmann, N. Sckopke, H. Rosenbauer, P. C. Hadgecock, The frontside boundary layer of the magnetosphere and the problem of reconnection, J. Geophys. Res., 83, 3195-, 1978.
Russell, C. T., G. Le, and H. Kuo, The occurrence rate of flux transfer events, Adv. Space Res., 18, (8)197-(8)205, 1996.
Sanny, J., C. Beck, and D. G. Sibeck, A statistical study of the magnetic signatures of FTEs near the dayside magnetopause, J. Geophys. Res., 103, 4683-4692, 1998.
Sibeck, D.G., A model for the transient magnetospheric response to sudden solar wind dynamic pressure variations, J. Geophys. Res., 95, 3755-, 1990.
Sibeck, D.G., W. Baumjohann, R. C. Elphic, D. H. Fairfield, J. F. Fennell, W. B. Gail, L. J. Lanzerotti, R. E. Lopez, H. Lühr, A. T. Y. Lui, C. G. Maclennan, R. W. McEntire, T. A. Potemra, T. J. Rosenberg, and K. Takahashi, The magnetospheric response to 8-minute-period strong-amplitude upstream pressure variations, J. Geophys. Res., 94, 2505-, 1989.