Evolution of global-scale coronal magnetic field due to magnetic reconnection: The formation of the observed blob motion in the coronal streamer belt

Citation
St. Wu et al., Evolution of global-scale coronal magnetic field due to magnetic reconnection: The formation of the observed blob motion in the coronal streamer belt, ASTROPHYS J, 545(2), 2000, pp. 1101-1115
Citations number
28
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICAL JOURNAL
ISSN journal
0004637X → ACNP
Volume
545
Issue
2
Year of publication
2000
Part
1
Pages
1101 - 1115
Database
ISI
SICI code
0004-637X(200012)545:2<1101:EOGCMF>2.0.ZU;2-B
Abstract
Recent SOHO/LASCO/EIT observations showed that the global corona at the min imum phase of cycle 22 is an organized, simple, and persistent dipolar conf iguration streamer belt (Michels). But the low-lying, closed-loop, multipol ar magnetic structure of the inner corona at low- to mid-latitudes revealed in EIT and LASCO images is not static. It stretches continuously outward, feeding plasma into higher coronal structures and eventually into the solar wind, including plasma blobs (Sheeley et al.; Wang et al.). To understand the physics of this slow dynamic evolution process, we use a two-dimensiona l, planar, resistive MHD model and observed pre-event characteristics for t he model input to simulate the formation and propagation of these observed plasma blobs. It seems that reconnection processes among the low-lying mult ipolar coronal loops and their overlying streamers cause the slow time evol ution. The motion of plasma blobs frequently observed by LASCO C2/C3 is ind eed reproduced by this model through reconnection in the multipolar loops. Results presented in this paper are the global field evolution, mass, momen tum, and energy transport from the inner corona to the outer corona and up into the streamer belt region where slow solar wind forms. We conclude that these plasma blobs may be the origin of the lumps in the solar wind observ ed in interplanetary space.