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971.
Gerhard Fanselau Heinz Kautzleben Otto Lucke Peter Mauersberger Kurt Sellien 《Pure and Applied Geophysics》1964,57(1):5-30
Zusammenfassung Es werden die Ergebnisse einer Berechnung des geomagnetischen Potentials in Form einer Reihenentwicklung nach Kugelfunktionen bis zur 15. Ordnung auf Grund der magnetischen Weltkarten für die Epoche 1945,0 vonE. H. Vestine und andern vorgelegt. Bei der Ableitung des Potentialausdrucks nach der Methode der kleinsten Quadrate wurden die Orthogonalitätseigenschaften der Kugelflächenfunktionen vollständig ausgenutzt.
Summary The results of the analysis of the main geomagnetic field for the epoch 1945.0 in a series of spherical harmonics to the 15th degree are presented. The analysis is based on the world magnetic charts derived byVestine et al. The coefficients of the potential are calculated by least-squares approximation taking advantage of the orthogonality of the spherical harmonics over discrete ranges.相似文献
972.
B. Böhnke 《Aquatic Sciences - Research Across Boundaries》1964,26(2):494-510
Ohne Zusammenfassung 相似文献
973.
Peter A. Gilman 《Pure and Applied Geophysics》1964,57(1):161-166
Summary The possible modes of vertical transport of angular momentum in the atmosphere are considered. Momentum balance calculations for both hemispheres show the possibility of countergradient transport by vertical eddies in the region of the mid-latitude jet. As a consequence, it is pointed out that the transport of momentum downward from the region of maximum westerlies would have to be accomplished by the mean meridional motions, through the action of Coriolis torques. The same mechanism may account for a large part of the upward transport in the tropics. The very approximate nature of the calculations must, however, be borne clearly in mind. 相似文献
974.
W. Mörikofer 《Meteorology and Atmospheric Physics》1956,9(4):524-526
Ohne Zusammenfassung 相似文献
975.
Zusammenfassung Es wurden zwei indische Lateritprofile untersucht. Die Lateritproben wurden soweit unverfestigt, in Korngrößenklassen zerlegt. Mit röntgenographischen. differentialthermoanalytischen und optischen Methoden wurde der Mineralbestand quantitativ bestimmt. Die Änderungen des Mineralbestandes und die Änderungen der Mineralverteilung wurde in den Lateritprofilen verfolgt.Die Lateritprofile sind auf quarzhaltigen Gesteinen, einem grobkörnigen Granit und einem feinkörnigen Quarz-Glimmer-Sandstein, entstanden. Als Ursache der Lateritbildung ist bei beiden Profilen die Verwitterung und Kaolinisierung des Ausgangsgesteins anzusehen. Bei dem Granit wurden die Feldspäte sowie die Hornblende und der Biotit, bei dem Sandstein wurde der Muskowit kaolinisiert. Der Quarz wurde mehr oder weniger stark korrodiert.Durch die Anreicherung von oxydischen und hydroxydischen Eisenmineralen in bestimmten Zonen der Verwitterungsprofile kam es zur Ausbildung typischer Lateritprofile mit konkretionsführenden bzw. pisolithischen Horizonten. Die Anreicherung von Eisenmineralen in diesen Horizonten ist durch Zufuhr von Eisen aus Verwittrungslösungen erfolgt. Das Eisen entstammt bei dem ersten Profil den verwitternden eisenhaltigen Mineralen des Granites, der Hornblende und dem Biotit. Bei dem zweiten Profil ist die Herkunft des Eisens aus verwitternden hämatitreichen Rindern des Sandsteines abzuleiten. An hydroxydischen Aluminiummineralen sind in beiden Lateritprofilen nur geringe Mengen Diaspur vorhanden.Auflösung von Kaolinit, Wanderung der Kaolinsubstanz und Neubildung von Fireclaymineral wurde in beiden Profilen nachgewiesen. 相似文献
976.
977.
A Three-Dimensional Global Model Study of Carbonyl Sulfide in the Troposphere and the Lower Stratosphere 总被引:4,自引:0,他引:4
Erik Kjellström 《Journal of Atmospheric Chemistry》1998,29(2):151-177
Global distributions of carbonyl sulfide and carbon disulfide have been calculated with a three-dimensional global model of the atmospheric general circulation (ECHAM). The model calculates a global sink strength for carbonyl sulfide of 0.3 Tg S yr-1, with vegetation uptake being the largest sink. With this sink strength, the sources have to be close to the lower limit of the present estimate in the literature. The calculated mixing ratios are higher in the Southern Hemisphere than in the Northern Hemisphere. This interhemispheric gradient is the opposite of what is observed demonstrating that the present knowledge of the distribution of sinks and sources is not fully adequate. The model calculations support the idea that the open oceans could act as a net sink of carbonyl sulfide. The calculated stratospheric photolysis of carbonyl sulfide constitutes about 4% of the total sink of carbonyl sulfide. A stratospheric production of sulfate from carbonyl sulfide of 0.013 Tg S yr-1 is obtained, which is 3 to 12 times less than what is needed to maintain the stratospheric sulfate aerosol layer. Although these results are associated with uncertainties, due to the low upper boundary and coarse vertical resolution of the model, they support recent findings of a low stratospheric production of sulfate from carbonyl sulfide. Instead, sulfur dioxide transported from the troposphere is calculated to be the most important precursor for the stratospheric sulfate aerosol layer. 相似文献
978.
A mass-flux approach is applied to observational data obtained in a convective boundary layer topped with stratocumulus clouds. The observational data were obtained from aircraft measurements during the Atlantic Stratocumulus Transition Experiment (ASTEX). A conditional sampling method is used to calculate average updraft and downdraft values. The vertical fluxes calculated with the mass-flux approach are found to be proportional to the real (measured) fluxes, with a proportionality factor being about 0.6. This value is predicted by theory for two variables having a joint Gaussian distribution function; proportionality factor = 2-1 0.637. The horizontal fractional entrainment and detrainment rates calculated from the data ( 1–2 × 10-2 m-1) are an order of magnitude higher than the rates obtained by large eddy simulations for cumulus convection ( 2–3 × 10-3 m-1) and two orders of magnitude higher than those used in modelling cumulus convection with a mass-flux scheme in an operational weather forecast model ( 3 × 10-4 m-1). A numerical mass-flux model for the thermodynamics was developed and showed that results are in good agreement when compared with measured profiles of the liquid water content. 相似文献
979.
980.
Stefan Bernstein Peter B Kelemen Christian Tegner Mark D Kurz Jurek Blusztajn C.Kent Brooks 《Earth and Planetary Science Letters》1998,160(3-4):845-862
Mafic and ultramafic intrusions in East Greenland adjacent to the offshore Greenland–Iceland ridge were emplaced 5–9 My after continental breakup at 55 Ma [1]. Rare earth element (REE) concentrations determined by secondary ion mass spectrometry are reported for cumulus clinopyroxene from these intrusions, and the data are used to estimate REE abundance in equilibrium melts using available partitioning data. Estimated equilibrium melts from intrusions have strongly fractionated REE patterns with Nd/Dy(N) in the range 2 to 5.6 and Yb/Dy(N) 0.55 to 0.92, similar to values for coeval basalts. These melts have markedly higher Nd/Dy(N) than earlier breakup related flood basalts. The moderately low Yb/Dy(N) for the post-breakup volcanism is indicative of residual garnet in the source, while their high Nd/Dy(N) ratios can best be explained by aggregating low degree melts from a light-REE-enriched garnet- and spinel-bearing mantle source. We also report He, Sr, and Nd isotopic data for the intrusions. The highest 3He/4He ratios (>10 R/Ra) are found in the samples whose REE data reflect the largest proportion of melts from a garnet-bearing source, and having Sr and Nd isotopic compositions identical with the radiogenic Sr and unradiogenic Nd isotope end of the Iceland compositional field. There is no indication of a MORB-type mantle in the source of the intrusions. We postulate that post-breakup volcanism along the East Greenland coastline reflects the increasing proximity of the mantle plume to the East Greenland continental margin. The low degree of melting at high mean pressure inferred for the parental melts for the intrusions may reflect re-thickening of the lithosphere, which in turn was caused by the vigorous volcanism during breakup, with accompanying depletion of upper mantle and underplating of the crust at the continental margin. 相似文献