Engineering topics
Publications and source records attributed to Sheeley, N. R., Jr..
Skylab XUV coronal spectroheliograms and photospheric magnetograms are compared. This comparison shows that, as new bipolar magnetic fields emerge through the solar surface into the corona, the new coronal fields interact with the old ones in a manner that suggests the reconnection of the field lines.
Spectroheliograms obtained with the Naval Research Laboratory's Extreme Ultraviolet Spectrograph (S082A) on Skylab are compared with Kitt Peak National Observatory magnetograms. A principal result is the characteristic reconnection of flux from an emerging bipolar magnetic region to previously existing flux in its vicinity. Examples of the disappearance of magnetic flux from the solar atmosphere are also shown. The results of a particularly simple, potential field calculation are shown for comparison with the Skylab observations.
By photographically averaging time sequences of high-resolution CN 3883-A spectroheliograms, the noise level due to the rapidly fluctuating intensity of the solar background has been reduced significantly. Very faint faculae that are lost in the noise on a single frame are easily visible on such an enhanced picture. A comparison between these enhanced spectroheliograms and a photoelectric magnetogram suggests that the brightness-magnetic field correlation extends to much weaker field strengths and fainter faculae than can be detected on a single, high quality CN spectroheliogram.
Two dimensional velocity field observations in and around sunspots from Doppler spectroheliograms
Solar velocity field decomposition into oscillatory and slowly varying components by spectroheliograms with high spatial resolution
Spectroheliogram Doppler movies of solar velocity fields showing oscillatory and slowly varying components