New studies show that the Sun's active regions — areas of intense eruptions — are formed from many small magnetic structures (white loops) that rise from deep within the interior, then pierce the surface to form sunspots (dark areas). These structures appear as giant arches when electrified gas (plasma) passes through their magnetic fields.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 184.108.40.206.0