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Priv.-Doz. Dr. Hans-Walter Georgii 《Pure and Applied Geophysics》1959,44(1):249-256
Zusammenfassung Messungen der Gefrierkernkonzentration während der Jahre 1957 und 1958 zeigten im Verlauf des Monats Januar markante Spitzenwerte, die zeitlich mit den vonE.G. Bowen vorhergesagten Maxima übereinstimmten. Da es große Schwierigkeiten bereitet, das Auftreten dieser Maxima durch die «Meteorstaubhypothese» zu erklären, wird auf Umstellungen der Zirkulation der Atmosphäre im Januar hingewiesen, die möglicherweise diese Schwankungen der Gefrierkernkonzentration auslösen können.
The research reported in this article has been sponsored and supported in part by the Geophysics Research Directorate, Air Force Cambridge Research Center, ARDC, under contract AF 61 (514)-927 through the European Office, ARDC. 相似文献
Summary Investigations on freezing nuclei show characteristic anomalies of the concentration during January 1957 and 1958. These anomalies fit in the schedule predicted byE.G. Bowen for the occurrence of high values of freezing nuclei. Since the explanation on the basis of the meteor-dust theory appears difficult, fluctuations of the atmospheric circulation during January may be responsible for the peak-values of the freezing nuclei concentration.
The research reported in this article has been sponsored and supported in part by the Geophysics Research Directorate, Air Force Cambridge Research Center, ARDC, under contract AF 61 (514)-927 through the European Office, ARDC. 相似文献
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A suite of vast stellar surveys mapping the Milky Way, culminating in the Gaia mission, is revolutionizing the empirical information about the distribution and properties of stars in the Galactic stellar disk. We review and lay out what analysis and modeling machinery needs to be in place to test mechanism of disk galaxy evolution and to stringently constrain the Galactic gravitational potential, using such Galactic star-by-star measurements. We stress the crucial role of stellar survey selection functions in any such modeling; and we advocate the utility of viewing the Galactic stellar disk as made up of ‘mono-abundance populations’ (MAPs), both for dynamical modeling and for constraining the Milky Way’s evolutionary processes. We review recent work on the spatial and kinematical distribution of MAPs, and point out how further study of MAPs in the Gaia era should lead to a decisively clearer picture of the Milky Way’s dark-matter distribution and formation history. 相似文献
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A three-stage vertical-flow thermal gradient vapour diffusion chamber for the fast, continuous measurement of the number concentration of cloud condensation nuclei (CCN) at three different water vapour supersaturations was constructed. CCN are monitored by imaging cloud droplets in the chamber with a CCD-camera. The counting of droplets and the control of all instrumental parameters are computerized. The instrument was calibrated with NaCl-aerosols, and was successfully operated in the field. Data from 2 weeks of field measurements at an island in the North Sea are presented. 相似文献
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Hans-Walter Georgii 《Pure and Applied Geophysics》1959,42(1):62-72
Zusammenfassung Es wird über parallele Untersuchungen der atmosphärischen Gefrierkerne und der Kondensationskerne berichtet, die an drei klimatisch verschidenen Meßorten — Frankfurt/M, Taunus Observatorium und Zugspitze — bei unterschiedlichen Witterungsbedingungen vorgenommen wurden. Im Verlauf der Untersuchungen zeigte sich eine starke Abhängigkeit der Aktivierungstemperatur der Gefrierkerne von der Teilchengröße der Kondensationskerne, die mit verschiedenen Methoden nachgewiesen werden konnte.
Summary Parallel measurements of freezing nuclei and condensation nuclei were carried out at three different locations — Frankfurt/M, Taunus observatory and Zugspitze — under various weather conditions. During these investigations a strong relation between the activation-temperature of freezing nuclei and the particle size of the condensation nuclei was detected and confirmed with different methods.相似文献
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Wolfgang Jaeschke Hans-Walter Georgii Hans Claude Helmut Malewski 《Pure and Applied Geophysics》1978,116(2-3):465-475
H2S is a most important biogenic sulfur compound with regard to the atmospheric sulfur cycle. Our present knowledge of the spatial and temporal distribution of this trace gas is rather incomplete owing to unreliable analytical methods. Therefore, a new method for the analysis of H2S in the g-range was applied. This paper deals with the results of ground- and aircraft measurements of H2S in unpolluted air over swamps and tidal flats. Based on the measured vertical distributions a removal coefficient of 2.3×10–5 sec–1 and an average lifetime of 12 hours were calculated. Some conclusions of the contribution of H2S to the atmospheric sulfur budget are added. 相似文献
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Dr. Hans-Walter Georgii 《Pure and Applied Geophysics》1957,36(1):127-137
Zusammenfassung Es wird über Versuche berichtet, die eine direkte und quantitative Bestimmung des Luftaustausches in Mulden und Gruben zum Ziele hatten. Die Bestimmung des in der Zeiteinheit ausgetauschten Luftvolumens erfolgt auf Grund laufender Messung der Konzentrationsabnahme künstlich erzeugter Aerosole, mit denen die in der Mulde stagnierende Luft markiert wurde. Die Geschwindigkeit der Konzentrationsabnahme und ihre Schwankungen sind ein Maß für die Größe des Austausches durch den turbulenten Mischungsprozeß. Die Persistenz der verwendeten, Aerosole wurde unter Berücksichtigung der Sedimentation, Koagulation und Eigendiffusion der Teilchen rechnerisch und experimentell abgeschätzt.
Herrn Professor Dr.R. Mügge zum 60. Geburtstag gewidmet. 相似文献
Summary Experiments to determine directly and quantitatively the exchange of air in little valleys and ditches are being described. The air is being marked with artificially produced aerosols. The decrease of concentration of these aerosols is continuously measured and is an indication for the size of the air-exchange by turbulent mixing. The sedimentation, coagulation and diffusion of the aerosol-particles, processes which also lead to a decrease of concentration, have been carefully studied beforehand.
Herrn Professor Dr.R. Mügge zum 60. Geburtstag gewidmet. 相似文献