Abstract:
Observations of an East-West asymmetry in photospheric fields, as reported by Duvall et al. (1979), Howard (1974), and Shrauner and Scherrer (1994) may possibly be explained as measurements of the component normal to the surface contaminated by a global, toroidal component. A toroidal component can also be inferred from its effect on chromospheric fine structure and by measurements of the magnetic fields inside and beneath solar filaments. It is proposed to take advantage of unique stability of observing conditions offered by the magnetograms from the SOHO Michelson-Doppler Imager (MDI) to study the evolution of fields as they cross the solar disk. Although the MDI is sensitive only to the line-of-sight component of the fields, toroidal fields may reveal themselves by East-West asymmetries in average field strength and in systematic shifts of large-scale features, such as the boundaries between positive and negative field areas.
Data sets required: Calibrated full-disk MDI magnetograms for at least a one-year period.
No additional text was submitted for this proposal.