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Extracts from Otto Jesse's papers relating to twilight studies, noctilucent clouds and atmospheric movements are presented here to illustrate his contribution to the subject during the years 1884-1901. The most important result of his activity was the establishment of the Berlin “Atmospheric Programme” which included regular monitoring of noctilucent clouds by visual and photographic means. Furthermore, Jesse studied problems of dynamic processes in noctilucent clouds and in the corresponding upper atmospheric layers.

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The seasonal frequency of noctilucent clouds has been discussed on the basis of visual data from the Northern Hemisphere. It is shown that there is a strong dependence on the atmospheric constitution at the mesospheric level and the seasonal transition in the mesopause. Before spring transition and after autumn transition of the mesosphere at the 80 km level no NLC are observed on the Northern Hemisphere.  Conversely we can conclude the same distribution for the Southern Hemisphere and the strong relation between transition periods and occurrence of NLC.

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The data of increased airglow during the night June 30–July 1, 1908 as the Tunguska event has been noted, are analyized in detail. During the nights June 30–July 1, and July 2, 1908 noctilucent clouds has been observed. Furthermore some increased airglow has been noted.

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Short definitions are given for “noctilucent clouds”, “polar mesospheric clouds” and “polar mesospheric summertime echoes” for practical use.

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Based on visual noctilucent cloud data, the effect of the autumn transition of winds in the mesosphere is investigated. Following the autumnal transition of the mesospheric winds no noctilucent clouds were observed. The higher temperature of the winter mesosphere can be physically explain the fact that no noctilucent clouds occur during winter of the Northern Hemisphere. Accordingly, noctilucent clouds only occur on the typical summer mesosphere related to the low temperature there and due to the stable condition of the then mesospheric region.

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Auroras observed visually during the July 1959 series of events are studied in this paper. Detailed investigation shows that the aurora of July 15/16 1959 was observed in the Northern hemisphere down to a latitude of 33\degree N and in the Southern hemisphere to 28°S. Morphologically nearly all auroral forms were observed, even at mid-latitudes. The July events including the auroral displays, can be attributed to extraordinary solar eruptions (class 3+).

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W Schröder ed.: The Einstein Century of Physics - The First Quarter (Collected papers by Hans-Jürgen Treder), Beitr. Gesch. Physik u. kosm. Physik, Science Ed., Bremen, Vol.\ 5, 2001, 52 pp; W Schröder ed.: Solar Variability and Geomagnetism. Beitr. Gesch. Geophysik u. kosm. Physik, Science Edition, Bremen/Potsdam, Vol. 3, No. 2, (and IAGA IDCH Newsletter, No. 44) 2002, 300 pp; W. Schröder ed.: Alte und neue Probleme der Physik und Geophysik. Beitr. Gesch. Geophysik u. kosm. Physik, Science Edition, Bremen/Potsdam, Vol. 4, No.1, (and IAGA IDCH Newsletter, No. 46), 2003, 160 pp; W. Schröder ed.: Leuchtende Nachtwolken/Noctilucent clouds. Beitr. Gesch. Geophysik u. kosm. Physik, Arbeitskreis Gesch. Geoph. u. kosm. Physik, Science Edition, Vol. 4, No. 2, 2003, 182 pp; W. Schröder ed.: Das Polarlicht (Hermann Fritz und die Polarlichtforschung)/The Aurora Borealis (Hermann Fritz and the Foundation of Auroral Research). Beitr. Gesch. Geophysik u. kosm. Physik,  Arbeitskreis Gesch. Geoph. u. kosm. Physik, Science Edition, Vol. 5, No. 1, 2004, 60 pp;

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