MDI Magnetograms with MWO software

Our recent proposal describes methods of reducing magnetic field observations through the application of the Shrauner-Scherrer vector resolution and corrections for differential rotation.

All observations of a point on the solar surface are combined for the period that this point is visible from SOHO. The point is tracked according to its local differential rotation rate. After the zonal (east-west) and meridional (line-of-sight projection of the field in the meridional plane) components are obtained by fitting, a heliographic map is then produced by correcting each pixels position for the position shift appropriate to the time of observation. We refer to the resulting maps as snapshot heliographic maps or snapshots.

As a sample of the output we give here a set of reductions for July, 15, 2002. These are centered at a Carrington longitude of 14 degrees and have a discontinuity on the opposite side at 194 degrees. The MDI data has not been adjusted to the MWO scale.

Magnetic Observations by the Michelson-Doppler Imager on SOHO Reduced with Algorithms developed for Mount Wilson Synoptic Magnetic Field Analysis