Flux Changes in Small Magnetic Regions. 2. Further Observations and Analysis

摘要

Further examples of flux changes are described in which the flux associated with small magnetic knots of dimension 2 sec - 3 sec is observed to increase or decrease by 50%-100% during periods of order 20-40 minutes. Within the same regions (8 sec X 8 sec) both positive and negative flux knots have been studied. In one case the positive and negative flux fluctuations appeared to be almost out of phase, but in another they were roughly in phase. From measurements of the velocity field within each region, an estimate of the vertical velocity shear has been calculated, and correlations of order 0.5 between the fluctuations in this shear and in both the positive and negative flux counts have been obtained in several, but not all cases. The possibility is discussed that these apparent flux changes are due to instrumental or seeing effects. changes in the line equivalent width, or vertical velocity gradients, but it is concluded that none of these effects provides a tenable alternative explanation of the observed changes. It is therefore suggested that these changes may provide examples of the generation of nonpotential magnetic fields (i.e., electric currents) within the photospheric layers, as has been proposed by several authors.