Showing papers by "Fraunhofer Society published in 1977"
TL;DR: In this article, the variations in time of the electric potential of the ionosphere were derived from high-mountain observatories, under certain conditions, by recording atmospheric electric field and air-earth current density I on high mountain observatories.
39 citations
TL;DR: In this article, a method has been developed for determining the possible effect of electrostatic attraction owing to image forces on the collection efficiency of tubular elutriators, and the quantitative importance of the effect is critically discussed.
9 citations
01 Jun 1977
TL;DR: In this paper, the frequency of intrusions of stratospheric air into the troposphere is influenced by solar events, and the data cover the period from end of 1969 to February 1975.
Abstract: Recordings of the Be7 and fallout in air and O3 obtained at a mountain observatory in 3 km altitude (Zugspitze) constitute the basis for a study of the question whether the frequency of intrusions of stratospheric air into the troposphere is influenced by solar events. The data cover the period from end of 1969 to February 1975.
7 citations
TL;DR: In this article, the authors present theoretical Ca ii K-line profiles and filtergram contrasts for several recent models of solar faculae, which greatly simplifies the calculation for comparison with observations.
Abstract: We present theoretical Ca ii K-line profiles and filtergram contrasts for several recent models of solar faculae. The line profiles vary greatly between models and between complete and partial frequency redistribution non-LTE calculations for any given model. The filtergram contrasts are relatively insensitive to the line formation theory which greatly simplifies the calculation for comparison with observations. All of the models considered exhibit K-line contrasts smaller than the mean value observed by Mehltretter.