info:eu-repo/semantics/article
Magnetic Topology of Active Regions and Coronal Holes: Implications for Coronal Outflows and the Solar Wind
Fecha
2012-11Registro en:
van Driel Gesztelyi, Lidia; Culhane, J. L.; Baker, D.; Démoulin, Pascal; Mandrini, Cristina Hemilse; et al.; Magnetic Topology of Active Regions and Coronal Holes: Implications for Coronal Outflows and the Solar Wind; Springer; Solar Physics; 281; 1; 11-2012; 237-262
0038-0938
CONICET Digital
CONICET
Autor
van Driel Gesztelyi, Lidia
Culhane, J. L.
Baker, D.
Démoulin, Pascal
Mandrini, Cristina Hemilse
DeRosa, M.L.
Rouillard, A.P.
Opitz, A.
Stenborg, G.
Vourlidas, A.
Brooks, D.H.
Resumen
During 2-18 January 2008 a pair of low-latitude opposite-polarity 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 AR-related outflows and measure their velocities. Solar-Terrestrial Relations Observatory (STEREO) imaging is also employed, as are the Advanced Composition Explorer (ACE) in-situ observations, to assess the resulting impacts on the solar wind (SW) properties. Magnetic-field extrapolations of the two ARs confirm that AR plasma outflows observed with EIS are co-spatial with quasi-separatrix layer locations, including the separatrix of a null point. Global potential-field source-surface 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 closed-field 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 in-situ data, we propose that the type of slow SW present depends on whether the AR is fully or partially enclosed by an overlying streamer. © 2012 Springer Science+Business Media B.V.