New design aspects of boomerang radio sondes for upper air research

Summary This paper deals with an entirely new type of aerological instrument, the Boomerang Radio Sonde. Its purpose is the presentation of the author’s results of a fundamentally new development based upon application of modern aeronautic as well as electronic engineering and carried out by him during the period 1950 to 1955. Boomerang Radio Sondes as carrier of upper air research instruments were first suggested byFritz H. W. Albrecht in 1943, in order to generally simplify the notoriously expensive present-day programme of aerological measurements. An estimated saving of approximately 60 % of total expenses of an ordinary radio sonde network can be expected if Boomerang Radio Sondes are utilized. The introduction describes and discusses the design work performed in Germany, by a team of research workers underFritz H. W. Albrecht during the period 1945–48, until a number of circumstances forced the temporary discontinuance of the project. Since 1950 the author has been in charge of the entire further development of the project and his design results are presented under ? Aerodynamic Design ? and ? Design of Electronic Control ? describing an entirely new design of Boomerang Radio Sondes and complete removal of serious engineering obstacles encountered 1945–48. Under the heading ? Research Applications ? possibilities of this new aerological instrument carrier are discussed.

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Zusammenfassung Diese Arbeit behandelt ein vollkommen neuartiges aerologisches Ger?t, die Bumerang Radio Sonde. Ihr Zweck ist die Ver?ffentlichung der Ergebnisse des Verfassers bei der fundamental neuen Entwicklung, die auf der Anwendung von moderner Aerodynamik und Elektronik basiert und von ihm w?hrend der Zeit 1950 bis 1955 ausgeführt wurde. Bumerang Radio Sonden als Tr?ger für Instrumente zur Erforschung oberer Luftschichten wurden zuerst vonFritz H. W. Albrecht 1943 vorgeschlagen, um das notorisch teure gegenw?rtige aerologische Messprogramm einfacher und wirtschaftlicher zu gestalten. Eine gesch?tzte Erspaon rnis ungef?hr 60 % der Gesamtkosten eines normalen Radiosondendienstes kann erwartet werden, wenn Bumerang-Radio-Sonden benutzt werden. Die Einführung beschreibt und diskutiert die Konstruktionsarbeit, die in Deutschland durch eine Forschungsgruppe unterFritz H. W. Albrecht w?hrend der Zeit 1945–48 ausgeführt wurde, bis eine Anzahl von Umst?nden die vorübergehende Aufgabe des Projektes erzwang. Seit 1950 ist der Verfasser für die gesamte weitere Entwicklung des Projektes verantwortlich und seine Konstruktionsresultate sind unter ? Aerodynamic Design ? und ? Design of Electronic Control ? ver?ffentlicht, indem eine vollkommen neue Konstruktion von Bumerang Radio Sonden und eine vollst?ndige Beseitigung von 1945–48 vorhandenen technischen Hindernissen beschrieben ist. Unter der überschrift ? Research Applications ? werden Anwendungsm?glichkeiten dieses neuen aerologischen Instrumententr?gers beschrieben.

     

Aplicación del cálculo de las diferencias al problema del efecto de embalse

Resumen Presentamos una solución numérica del problema del efecto de embalse con ayuda de una ecuación lineal inhomogénea en diferencias finitas de primer orden, suponiendo una ley lineal del desagüe. Este método numérico es de maneje cómodo para un cálculo aproximado.

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Zusammenfassung Es wird die numerische Bestimmung der Seeretention mittels der Lösung einer linearen inhomogenen Differenzengleichung 1. Ordnung dargelegt. Dieses numerische Verfahren ist für eine Näherungsrechnung besonders geeignet.

     

Zum Jahresgang der relativen Feuchte über dem Mittelmeer

Zusammenfassung Abweichend von der in einem früheren Aufsatz versuchten Erklärung der sommerlichen Feuchtezunahme über dem Mittelmeer wird plausibel gemacht, daß im wesentlichen die normale Erhöhung der Temperatur der Meeresoberfläche dafür verantwortlich ist.

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Summary Earlier in this journal an article was published, which suggested that the increase of the relative humidity in the warmer season of the Mediterranean was effected by subsiding of dry air from above and therefore increasing evaporation. But now it seems to the author that only the normal annual variation of the sea surface temperature is responsible for the observed phenomenon.

     

Buchbesprechungen

Ohne Zusammenfassung     

Improved numerical dissipation for time integration algorithms in structural dynamics

A new family of unconditionally stable one-step methods for the direct integration of the equations of structural dynamics is introduced and is shown to possess improved algorithmic damping properties which can be continuously controlled. The new methods are compared with members of the Newmark family, and the Houbolt and Wilson methods.     

An island arc origin for the Canyon Mountain ophiolite complex,eastern Oregon,U.S.A.

The Canyon Mountain ophiolite, Oregon, is exceptional in lacking sheeted dikes, basaltic pillow lavas, and sediments that are characteristic of many other ophiolites. Instead, the uppermost portion of the complex consists of a significant volume of plagiogranites, which, in addition to minor basalts, intrude a large section of keratophyres believed to be of volcanic origin. The trend of intrusive rocks and of bedding in the keratophyres is mostly parallel to layering in the underlying gabbroic cumulates and to contacts between units in the remainder of the ophiolite. It is suggested that the plagiogranites, basalts, and keratophyres comprise a sill complex. Both the plagiogranites and the keratophyres are similar, respectively, to low-K₂O plutonic and extrusive rocks of island arcs. The mineralogy and penetrative deformation structures of the ultramafic and some of the gabbroic rocks of the ophiolite indicate greater depth of formation, related to magmatism and diapirism above a Benioff zone. Radiometric age dates of plagiogranites confine the minimum age of the complex to the Early Permian. The Canyon Mountain ophiolite may thus be correlative with other fragments of a Lower Permian arc terrane throughout northeastern Oregon which were chaotically mixed during renewed subduction in middle to late Triassic time.     

Dünung und Windstau

Summary These remarks trie to explain the behaviour of local wind effect on the coast under the additional influence of swell approximately running parallel to the wind's direction. Owing to the high speed of long swell waves the wind's tangential shearing strain on the water masses may become less effective than it would do if no coincidence with swell waves would occur.

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La houle et l'effet local du vent

Résumé Cet essai cherche à expliquer le comportement de l'effet local du vent sous l'influence additionnelle d'une houle qui suit approximativement la direction du vent. Par suite de la grande vitesse de propagation d'une longue houle, l'effet de cisaillement tangentiel que le vent exerce sur l'eau diminuera dans le cas où l'effet local du vent coincide avec le phénomène additionnel de la houle.

     

Paleomagnetism of red beds of Early Devonian age from Central Iran

Paleomagnetic results are reported from 13 sites of red beds of Early Devonian age from Central Iran. Detailed paleomagnetic analyses were carried out. Two types of partial progressive demagnetization were applied, one using alternating magnetic fields, the other heating. These procedures resulted in the detection of the characteristic remanences with a mean direction with D = 24.2°, I = 1.3° (α₉₅ = 10.1°). The paleomagnetic pole is located at 51.3°N, 163.7°W. If one shifts the Iranian landmass to its most likely position in the Gondwana configuration, then the position of the paleomagnetic pole coincides with the alternative polar wander path [14,15] which crossed South America in early Middle Paleozoic times.     

Late Holocene flood magnitudes in the Lower Rhine river valley and upper delta resolved by a two-dimensional hydraulic modelling approach

Palaeoflood hydraulic modelling is essential for quantifying ‘millennial flood’ events not covered in the instrumental record. Palaeoflood modelling research has largely focused on one-dimensional analysis for geomorphologically stable fluvial settings because two-dimensional analysis for dynamic alluvial settings is time consuming and requires a detailed representation of the past landscape. In this study, we make the step to spatially continuous palaeoflood modelling for a large and dynamic lowland area. We applied advanced hydraulic model simulations (1D–2D coupled set-up in HEC-RAS with 950 channel sections and 108 × 10³ floodplain grid cells) to quantify the extent and magnitude of past floods in the Lower Rhine river valley and upper delta. As input, we used a high-resolution terrain reconstruction (palaeo-DEM) of the area in early mediaeval times, complemented with hydraulic roughness values. After conducting a series of model runs with increasing discharge magnitudes at the upstream boundary, we compared the simulated flood water levels with an inventory of exceeded and non-exceeded elevations extracted from various geological, archaeological and historical sources. This comparison demonstrated a Lower Rhine millennial flood magnitude of approximately 14,000 m³/s for the Late Holocene period before late mediaeval times. This value exceeds the largest measured discharges in the instrumental record, but not the design discharges currently accounted for in flood risk management.