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R. L. Moore (NASA/MSFC/NSSTC), Y. Yamauchi (NJIT/Center for Solar-Terrestrial Research)
We present an example of each of the following observed characteristics of the magnetic origins of quiet-region coronal heating, spicules, macrospicules, and coronal mass ejections (CMEs). (1) In quiet regions, the luminosity of the corona is roughly proportional to the edge length of the underlying photospheric magnetic network (Falconer et al 2003, ApJ, 593, 549). (2) Spicules and EUV explosive events are concentrated at the edges of the magnetic network (e.g., Beckers, J. M. 1968, Sol. Phys., 3, 367; Porter, J. G. & Dere, K. P. 1991, ApJ, 370, 775). (3) Many macrospicules have the magnetic structure of a surge rooted around an inclusion of opposite-polarity magnetic flux (Yamauchi, Y. et al 2004, ApJ, in press). (4) CMEs and eruptive flares are driven by explosions of sheared magnetic fields rooted along polarity dividing lines (neutral lines) in the photospheric magnetic flux (e.g., Moore, R. L. et al 2001, ApJ, 552, 833). These characteristics together suggest that the mainstay of the heliosphere, the corona/solar wind rooted in quiet regions and coronal holes, may be driven by myriads of tiny magnetic explosions at the network edges, explosions like those that drive CMEs but of vastly smaller scale. If so, the steady solar wind and the CMEs that disrupt it both have the same root cause: explosions of initially- closed, strongly-sheared, bipolar magnetic fields. The photospheric vector magnetograms, chromospheric filtergrams, EUV spectra, and coronal images from Solar-B are expected to have sufficient sensitivity, spatial resolution, and cadence to test this scenario for coronal heating in quiet regions and coronal holes. This work was supported by NASA/OSS through its Solar & Heliospheric Physics SR&T Program and Sun-Earth Connection GI Program.
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Bulletin of the American Astronomical Society, 36 #2
© YEAR. The American Astronomical Soceity.