In memoriam     

Walter Stahlberg 《Ocean Dynamics》1951,4(4-6):197-197

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Geodetic applications of eclipses and occultations     

Walter D. Lambert 《Journal of Geodesy》1949,23(3):274-292

If in imagination we viewed a solar eclipse or the occultation of a star from a point outside the earth, we would see the shadow of the moon advancing across the face of the earth, the earth meanwhile turning on its axis beneath the shadow. When some point on the advancing edge of the shadow overtook a given point on the surface of the earth, an observer at that point would note the beginning of the eclipse or occultation. When the trailing edge of the shadow uncovered that point again, the observer there would note the end of the eclipse or occultation. The universal time (as distinguished from the local time) of the beginning or ending would depend on the position of the observer with reference to the body of the earth, that is, on his ideal geodetic coordinates. These universal times would not depend in the least on the direction of the observer’s vertical. This fact is the key to the usefulness of eclipses and occultations for geodetic purposes. Suppose that the prediction for the times of beginning or ending had been made on the basis of the astronomical latitude and longitude of the observer. Since there would be in general deflections of the vertical in latitude and longitude, Δπ and Δλ, these would bring about, even in the absence of any other source of discrepancy, diffe- This article is at once a condensation and an expansion. It is a condensation of a series of lectures delivered in the winter and spring of 1947 to members of the U. S. Coast and Geodetic Survey and of the Army Map Service. It is an expansion of a very informal lecture given before Section III of the International Association of Geodesy, meeting in General Assembly at Oslo in August, 1948.  相似文献   

Die Bedeutung der Isotopenforschung für die Geologie     

Walter Wahl 《International Journal of Earth Sciences》1942,32(4-5):550-562

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Neuere Veröffentlichungen     

Günter Dietrich  Walter Hansen  A. Schumacher  F. Errulat 《Ocean Dynamics》1952,5(2-3):153-156

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Trägheitsschwingungen in offenen und abgeschlossenen Meeresgebieten     

Walter Hansen 《Ocean Dynamics》1948,1(1):18-29

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Über die Darstellung der Gezeiten als Funktion der Zeit     

Walter Horn 《Ocean Dynamics》1948,1(4):124-140

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Walter Carle 《International Journal of Earth Sciences》1936,27(6):499

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Zur Alpensynthese     

Walter Del-Negro 《International Journal of Earth Sciences》1929,20(4-5):341-342

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Bildung von Kondensationskernen durch UV-Strahlung in verschiedenen Gasen     

Walter Hoppe 《Pure and Applied Geophysics》1961,50(1):129-139

Zusammenfassung Die Erzeugung von Kondensationskernen durch UV-Licht wurde mittels eines automatischenPollakschen Kernzählers und einerWilsonkammer aus Glas untersucht. Da die UV-Kerne von einem Schwebstoffilter zurückgehalten werden, ließ sich durch Verwendung zweier Bestrahlungsgefäße mit dazwischengeschaltetem Filter die Spurengashypothese bestätigen. Bestrahlungsversuche in Luft, Stickstoff, Sauerstoff, Argon und Wasserstoff ergaben, daß durch längere Bestrahlung eines abgeschlossenen Gasvolumens die kernbildende Substanz allmählich verbraucht wird. Durch Zugabe definierter Mengen gasförmigen Ammoniaks in den Bestrahlungsraum zeigte sich, daß die von verschiedenen Autoren geäußerte Ansicht, gasförmiges Ammoniak sei die kernbildende Substanz, nicht haltbar ist. Die Untersuchung des Einflusses von Schwefelwasserstoff bzw. Schwefeldioxyd ergab, daß die atmosphärische Konzentration von H₂S zur Erklärung des UV-Effektes nicht ausreicht, während dies bei SO₂ der Fall ist. Das Ergebnis, daß SO₂ maßgebend an der Bildung der UV-Kerne in atmosphärischer Luft beteiligt ist, wird dadurch gestützt, daß der UV-Effekt einen ähnlichen Tagesgang zeigt wie das atmosphärische SO₂.

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Summary The production of condensation nuclei by UV light was investigated by means of an automaticPollak nucleus counter and aWilson glass-chamber. As the UV nuclei can be removed by an aerosol filter, the trace gas hypothesis could be confirmed by using two irradiation tubes separated by an aerosol filter. Irradiation experiments in air, nitrogen, oxygen, argon and hydrogen in a closed volume had the result that the nucleogenic substance gradually disappears after sufficiently long irradiation. By adding definite quantities of ammonia vapour into the irradiation tube it could be shown that ammonia is not the nucleogenic substance, as was supposed by some authors. The investigation of the influence of sulphur dioxide and hydrogen sulfide showed that the atmospheric concentration of H₂S is not sufficient to explain the UV effect in atmospheric air, whereas this is true with SO₂. The result that SO₂ takes part in the formation of the UV nuclei is supported by the fact that SO₂ and the UV effect show a similar diurnal variation.

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Mean and Turbulent Flow Statistics in a Trellised Agricultural Canopy     

Nathan E. Miller  Rob Stoll  Walter F. Mahaffee  Eric R. Pardyjak 《Boundary-Layer Meteorology》2017,165(1):113-143

Flow physics is investigated in a two-dimensional trellised agricultural canopy to examine that architecture’s unique signature on turbulent transport. Analysis of meteorological data from an Oregon vineyard demonstrates that the canopy strongly influences the flow by channelling the mean flow into the vine-row direction regardless of the above-canopy wind direction. Additionally, other flow statistics in the canopy sub-layer show a dependance on the difference between the above-canopy wind direction and the vine-row direction. This includes an increase in the canopy displacement height and a decrease in the canopy-top shear length scale as the above-canopy flow rotates from row-parallel towards row-orthogonal. Distinct wind-direction-based variations are also observed in the components of the stress tensor, turbulent kinetic energy budget, and the energy spectra. Although spectral results suggest that sonic anemometry is insufficient for resolving all of the important scales of motion within the canopy, the energy spectra peaks still exhibit dependencies on the canopy and the wind direction. These variations demonstrate that the trellised-canopy’s effect on the flow during periods when the flow is row-aligned is similar to that seen by sparse canopies, and during periods when the flow is row-orthogonal, the effect is similar to that seen by dense canopies.  相似文献