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On the role of the chirality of solar magnetic fields in geomagnetic events.

Alexei A. Pevtsov


Magnetic fields on the Sun exhibit two specific hemispheric dependencies: the Hale- Nicholson polarity law and the hemispheric helicity rule. As a result, the meridional component of the field in both hemispheres will be oriented preferentially southward (northward) during even (odd) numbered solar cycles (Bothmer and Rust  1997). Similar cyclic behavior should also be seen in the orientation of the magnetic field in coronal mass ejections and hence, be present in geomagnetic indexes. We use the Ap-index and the sunspot number for solar cycles 17-22 to show that the expecterd trend is indeed present in these data.

  Organization: Montana State University
     Telephone: 406-994-7839
           Fax: 406-994-4452
        e-mail: pevtsov@physics.montana.edu
       Address: Department of Physics
   Montana State University
   Bozeman, MT 59717-3840

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