Geomagnetic storms and their sources on the sun:the rising phase of the sunspot cycle

• Main Authors: Takao Saito, Syun-Ichi Akasofu, Shinichi Watari, Natsuo Sato, Hiroaki Misawa
• Format: Article
• Language: English
• Published: National Institute of Polar Research 2013-03-01
• Series: Antarctic Record
• Online Access: http://doi.org/10.15094/00009679

Solar phenomena, including solar flares and coronal holes, are considered in the context of a NEWS coordinate system, obtained by application of the heliographic and heliomagnetic coordinate systems to the solar latitude and longitude, respectively. By expressing the occurrence of solar phenomena in terms of NEWS coordinates, we discovered that solar flares tend to converge in the NE and SW quadrants of the solar disk, where they act as sources of sporadic storms. Meanwhile, coronal holes converge to solar longitudes of 0° and 180°, where they are sources of recurrent storms. Because of their concentration in the NE- and SW-quadrants, this correlation is referred to as the 'NEWS law'. The neutral line of the source surface shows a beautiful single wave in its declining phase, while it tends to show a double wave in the rising phase. Solar rotation numbers 2118 to 2119, where the neutral line exhibited two complicated asymmetric waves in both the N-S and S-W directions, were chosen for detailed analysis. Notwithstanding such an extremely complicated case, the NEWS law is satisfied when the double wave is separated into its two single-wave parts.