The Theory of the Beta-Plane Baroclinic Topographic Modons     

Ziv Kizner  Dimitry Berson  Gregory Reznik  Georgi Sutyrin 《地球物理与天体物理流体动力学》2013,107(3):175-211

Form-preserving, uniformly translating, horizontally localized solutions (modons) are considered within the framework of nondissipative quasi-geostrophic dynamics for a two-layer model with meridionally sloping bottom. A general classification of the beta-plane baroclinic topographic modons ( g -BTMs) is given, and three distinct domains are shown to exist in the plane of the parameters. The first domain corresponds to the regular modons with the translation speed outside the range of the phase speeds of linear waves. In the second domain, modons cannot exist: only non-localized solutions are permissible here. The third domain contains both linear periodic waves and the so-called anomalous modons traveling without resonant radiation. Exact modon solutions with piecewise linear relation between the potential vorticity and streamfunction are found and analyzed. Special attention is given to the smooth regular dipole-plus-rider solutions (anomalous modons cannot carry a smooth axisymmetric rider). As distinct from their flat-bottom analogs, g -BTMs may have nonzero total angular momentum. This feature combined with the ability of g -BTMs to bear smooth riders of arbitrary amplitude provides the existence of almost monopolar (in both layers) stationary vortices.  相似文献   

Steadily translating anticyclones on the beta plane     

J. Nycander  G. G. Sutyrin 《Dynamics of Atmospheres and Oceans》1992,16(6)

Approximately stationary anticyclones in shallow water on a rotating planet are studied both analytically and numerically. They consist of a monopolar part with large amplitude and a dipolar part with small amplitude, proportional to the beta parameter. An explicit solution for the dipolar part is o obtained with an arbitrary radial profile of the monopolar part. Numerical experiments show that this dipolar part accelerates or decelerates an initially circular vortex depending on the vortex size. The propagation speed is determined by a general integral relation. It is found that for the vortices to be stationary, this speed should not be close to the phase velocity of linear Rossby waves. This requires a strongly elevated surface (large amplitude). The vortices contain a core region with trapped fluid, unlike one-dimensional KdV solitons. Applications of the solution to long-lived geophysical eddies are discussed.  相似文献   

Entgegnung zu den vorstehenden Bemerkungen     

Dr. J. Georgi 《Pure and Applied Geophysics》1955,30(1):182-184

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Bemerkungen zu T.E. Aurén,Studies of Solar Radiation 1951     

Dr. J. Georgi 《Pure and Applied Geophysics》1954,28(1):301-307

Zusammenfassung Die vonT. E. Aurén entwickelte Methode, aus einer grossen Anzahl von Messungen der Totalstrahlung der Sonne Kurven der mittleren Maxima zu gewinnen, wird befürwortet. Diese Kurven repräsentieren die für jeden Messort charakteristische, optimale Durchlässigkeit der Atmosphäre. Sie können daher auch als strahlungsklimatischer Parameter verstanden werden, sei es etwa als Intensität des solaren Strahlungsstromes bei bestimmten Höhenwinkeln, oder als Tagessummen usw.  相似文献   

Sunrise effects in the lowerD-Region by solar eclipse     

Georgi T. Nestorov 《Pure and Applied Geophysics》1968,71(1):5-14

Summary In contrast to the well known fact that the ionospheric absorption minimum falls behind the maximum phase of the solar eclipse, in the present work the reverse effect is discovered and analysed, namely that the ionospheric absorption minimum falls before the maximum phase of the eclipse, while the maximum absorption comes behind it. Such anomalies can be observed only on paths of long waves at oblique incidence of the layer (length of the path over 1300 km). The theoretical analysis shows that the established effects are due to the considerable increase of the factor of negative ions, respectively of the effective recombination coefficient in the first phase of the eclipse for heights between 65 and 70 km, i. e. in the lower boundary of theD-Region (CR-Layer). In the second phase of the eclipse falls rapidly because of which at a constant electron production inCR-layer a strong increase of the absorption is observed similar to the known sunrise effects in theD-Region. The electron drift is intensified about the maximum phase of the eclipse.  相似文献   

Die chemische Zusammensetzung des Sestons in inneren Küstengewässern der DDR (Darß–Zingster Boddengewässer,südliche Ostsee)     

F. Georgi 《洁净——土壤、空气、水》1986,14(6):581-594

Investigations were made on 27 seston samples of the years of 1978, 1979 and of the first half-year of 1982 from a station in the Zingster Strom. The mean contents – as mg/g dry matter – are: ash-free dry matter 569, C_total 284, C_inorg. 14, N_total 29, P_total 3.6, Fe_HCl-soluble 13. From them resulted the following weight quotients: C : N = 9.9 ± 2.4, C : P = 83 ± 21, N : P = 8.4 ± 1.8, Fe : P = 3.6 ± 1.0. The mean proportion of carbohydrate and the mean protein content amount to 170 and 180 mg/g, resp., dry matter. All parameters show pronounced dependences on seasonal and hydrographic situations, mainly the effects of wind on the very shallow water being of primary importance to the distribution and nature of seston.  相似文献   

Hydrodynamical simulations of the decay of high-speed molecular turbulence – I. Dense molecular regions     

Georgi Pavlovski  Michael D. Smith  Mordecai-Mark Mac Low  Alexander Rosen 《Monthly notices of the Royal Astronomical Society》2002,337(2):477-487

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The stability of buoyant bubbles in the atmospheres of galaxy clusters     

Christian R. Kaiser  Georgi Pavlovski  Edward C. D. Pope  Hans Fangohr 《Monthly notices of the Royal Astronomical Society》2005,359(2):493-503

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Petrography and geochemistry of granitoid and metamorphite pebbles from the early Archaean Moodies Group,Barberton Mountainland/South Africa     

Thomas O. Reimer  Kent C. Condie  Gabriele Schneider  Angelika Georgi 《Precambrian Research》1985,29(4):383-404

Pebbles of potassic granitoids and metamorphites constitute up to 5% of the basal conglomerate of the Moodies Group in a ratio of 2 : 1. The granitoid pebbles frequently show micrographic quartz–feldspar intergrowth, whereas the metamorphites—of a modal composition similar to that of the granitoids—are characterized by large quartz grains which could represent original quartz phenocrysts in felsic volcanic precursors.The granitoids show high K₂O, Sr, K₂O/Na₂O, and K/Rb, small enrichment of light REE, large negative Eu-anomalies, and slightly depleted and fractionated heavy REE. Compared to the granitoids the metamorphites show higher Fe₂O₃, TiO₂, and Cr concentrations, greater enrichment of light REE, and also large negative Eu-anomalies.There is little similarity between the Moodies pebbles and the majority of the rocks of the Ancient Gneiss Complex of Swaziland (AGC). There is only some similarity of the REE distribution patterns between the pebbles and the Mkhondo Metamorphic Suite, possibly an areally restricted phase of the AGC. The geochemical data, and especially the large negative Eu-anomalies suggest that the Moodies pebbles were derived from granites which represent residual magmas from which much plagioclase had been removed. The granites crystallized at depths of < 7 km from magmas with low H₂O-pressures in a rather thick sialic crust. It appears possible that the pre-Moodies granitoids originated through partial melting of low-Al₂O₃ siliceous gneisses of the AGC. A chronologic connection of the formation of the granitoids with the late Onverwacht Group volcanicity is possible.  相似文献   

Geohazards assessment and mapping of some Balkan countries   总被引：1，自引：0，他引：1  

Betim Mu?o  Georgi Alexiev  Shyqyri Aliaj  Zenun Elezi  Bogdan Grecu  Neculai Mandrescu  Zoran Milutinovic  Mircea Radulian  Boyko Ranguelov  Defrim Shkupi 《Natural Hazards》2012,64(2):943-981

The assessment of geological hazard is a topic with significant interest for the Balkans. During the last decade of twentieth century, most of the countries in the region have embarked on the road of a hasty transitory period from totalitarian regimes to democracy. Development of free market economy has given rise to uncontrolled movement of people, fast construction of housing and facilities and unproportioned accumulation of population around and in big cities. Besides Greece, an old member of European Union, and two newcomers in the organization, Romania and Bulgaria, the other countries are all hoping to enter the Union as faster as they can. Many different candidate or full-fledged member country programs of European Community offer a lot of joint and cross-border projects for constructing road infrastructure and facilities. As development accelerates in the Balkans and given the intensive geohazard elements that this territory exhibits, it becomes increasingly important to understand, study, and map these elements for being aware of the damage to the total environment these hazards might cause. The geohazard map and assessment of some Balkan countries has been carried out through two scientific meetings in Ohrid, Macedonia, and Tirana, Albania during 2007. The map is compiled in the Albanian Geological Survey, Tirana, Albania in the scale 1:1,000,000. As a base map, we used the topographic map produced by VGI, formerly Yugoslavia mapping authorities. As a seismic layer in our map, we used the values of peak ground acceleration obtained from Global Seismic Hazard Assessment Program. Two catalogs were constructed: The first one that contains the crustal earthquakes (hypocentral depth within first 70?km) and the second one that contains intermediate earthquakes (hypocentral depth below 70?km). This work is largely based on previous studies and investigations by earth scientists and specialists of each country comprised in this territory. In this respect, the map we constructed should be considered as a preliminary composite geohazard map with the possibility to be enriched and added with other new elements and data in the future.  相似文献