Authors: L van DrielGesztelyi J L Culhane D Baker P Démoulin C H Mandrini M L DeRosa A P Rouillard A Opitz G Stenborg A Vourlidas D H Brooks
Publish Date: 2012/09/07
Volume: 281, Issue: 1, Pages: 237-262
Abstract
During 2 – 18 January 2008 a pair of lowlatitude oppositepolarity coronal holes CHs were observed on the Sun with two active regions ARs and the heliospheric plasma sheet located between them We use the Hinode/EUV Imaging Spectrometer EIS to locate ARrelated outflows and measure their velocities SolarTerrestrial Relations Observatory STEREO imaging is also employed as are the Advanced Composition Explorer ACE insitu observations to assess the resulting impacts on the solar wind SW properties Magneticfield extrapolations of the two ARs confirm that AR plasma outflows observed with EIS are cospatial with quasiseparatrix layer locations including the separatrix of a null point Global potentialfield sourcesurface modeling indicates that field lines in the vicinity of the null point extend up to the source surface enabling a part of the EIS plasma upflows access to the SW We find that similar upflow properties are also observed within closedfield regions that do not reach the source surface We conclude that some of plasma upflows observed with EIS remain confined along closed coronal loops but that a fraction of the plasma may be released into the slow SW This suggests that ARs bordering coronal holes can contribute to the slow SW Analyzing the insitu data we propose that the type of slow SW present depends on whether the AR is fully or partially enclosed by an overlying streamer
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