COMPARISON OF POLAR AND EQUATORIAL MAGNETIC-FIELDS NEAR SUNSPOT MINIMUM

We investigate the polar magnetic fields near sunspot minimum using hi gh-resolution videomagnetograph data from Big Bear Solar Observatory. To avoid the problem of center-to-limb variation of the projected long itudinal held, we compare polar with equatorial held strengths for the same limb distance. Polar fields are stronger than the quiet equatori al field, but no greater than equatorial limb data containing unipolar regions. The difference is entirely in the stronger field elements. T he polar background fields are of mixed polarity but show a net weak f ield opposite in sign to that of the stronger polar elements. We belie ve this to be the first evidence of widespread background field. No de pendence of the measured signal on the B-angle was found, so the high- latitude fields do not change strength near the pole. Further, there w as no significant change in the polar fields in the 15-month period st udied. We tried to derive a high-latitude rotation rate; our data show motion of high-latitude magnetic elements, but the diurnal trajectory is not much bigger than random motions and field changes, so the resu lt is inconclusive. We suggest that the polar fields represent the acc umulation of sunspot remnants, the elements of which last for years in the absence of other fields.