Authors: Mandy Hagenaar
Affiliation: Lockheed Martin
We study combinations of SOHO-MDI, TRACE, and ground-based observations in order to find properties of Moving Magnetic Features (MMFs) around three sunspots. We measure frequency, flux content, lifetime, and velocity with respect to the surrounding plasma and moat cells around sunspots. We find that MMFs, just after being recognized, move with a typical velocity a little over 1 km/sec; have a flux content of (7-8)x10^18 Mx; which increases in about 15 minutes to (12-14)x10^18 Mx. Some theoretical interpretations of the real identity of MMFs are discussed: they may be associated with field lines detached from a decaying spot, or with closed magnetic loops. We discuss the role of MMFs in the dynamics of upper layers of the atmosphere, as reflected by coronal emission in TRACE 171 A. Coronal emission does not show immediate response to the birth and disappearance of individual MMFs, but may be visible in coronal loops between opposite-polarity sunspots in active regions.