Observation and Interpretation of Photospheric Line Asymmetry Changes Near Active Regions
Changes in spectral line asymmetries between regions of quiet sun and regions containing varying amounts of magnetic flux were observed. The observed asymmetry changes are used to deduce parameters that describe the local state of convective overshoot. From these parameters we deduce how the local convective energy flux depends on magnetic fields within the observed regions. Observations were obtained during five separate observing runs between July 1983 and February 1987. We observe FeI 5434 and FeI 6302. Fe 5434 is not split in magnetic regions while 6302 is used to map out the longitudinal component of the field. Additionally we obtain a K-line slit jaw image to locate areas of plage. The observations indicate that magnetic fields decrease the flux carried by convective elements deep in the photosphere, but permit the elements to overshoot higher into the photosphere and temperature minimum regions. The quantitative effect on the convective transport depends strongly on the strength of the magnetic field.
KeywordsSolar Phys Disk Center Magnetic Region National Solar Observatory Photospheric Line
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