|
Titel |
Blob formation and acceleration in the solar wind: role of converging flows and viscosity |
VerfasserIn |
G. Lapenta, A. L. Restante |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
0992-7689
|
Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 26, no. 10 ; Nr. 26, no. 10 (2008-10-15), S.3049-3060 |
Datensatznummer |
250016252
|
Publikation (Nr.) |
copernicus.org/angeo-26-3049-2008.pdf |
|
|
|
Zusammenfassung |
The effect of viscosity and of converging flows on the formation of blobs in
the slow solar wind is analysed by means of resistive MHD simulations. The
regions above coronal streamers where blobs are formed (Sheeley et al.,
1997) are
simulated using a model previously proposed by Einaudi et al. (1999). The result
of our investigation is two-fold. First, we demonstrate a new mechanism for
enhanced momentum transfer between a forming blob and the fast solar wind
surrounding it. The effect is caused by the longer range of the electric
field caused by the tearing instability forming the blob. The electric field
reaches into the fast solar wind and interacts with it, causing a viscous
drag that is global in nature rather than local across fluid layers as it is
the case in normal uncharged fluids (like water). Second, the presence of a
magnetic cusp at the tip of a coronal helmet streamer causes a converging of
the flows on the two sides of the streamer and a direct push of the forming
island by the fast solar wind, resulting in a more efficient momentum
exchange. |
|
|
Teil von |
|
|
|
|
|
|