Magnetic reconnection along QSLs - a major driver of active region outflows

BAKER, D.; VAN DRIEL-GESZTELYI, L.; MANDRINI, C.H.; DÉMOULIN, P.

Bremen

Congreso; 38th COSPAR Scientific Asssembly; 2010

Committee on Space Research

The relationship between quasi-separatrix layers (QSLs), or in the limit of infinitely thin QSLs, separatrices, and various activity phenomena has been explored in many different solar magnetic configurations across all scales in recent years. In the absence of magnetic nulls, fast reconnec-tion along QSLs, which are specific locations in the magnetic topology where field lines display strong gradients of magnetic connectivity, was identified as the main physical process at the origin of flares. Recently, it was shown that fast (tens of km/s) persistent hot plasma upflows in active regions (ARs) can also be linked to locations of QSLs. It is likely that these upflows that occur at the edges of ARs over unipolar magnetic field concentrations are accelerated by magnetic reconnection along QSLs. We will show multi-temperature spectral scan observations from Hinode's EIS combined with magnetic modeling of QSLs in two ARs observed on 20-21 February 2007 and 11 January 2008. The latter AR is observed and modeled when it is in the vicinity of the solar central meridian where there are no projection effects, thereby eliminating ambiguity linking the origin of multi-temperature observations of AR upflows to QSLs. We use the Potential Source Surface Model to look for open field lines in the vicinity of upflows and QSL locations in order to demonstrate whether these upflows become outflows and can contribute to the solar wind.