Study of the air-sea interactions at the mesoscale: the SEMAPHORE experiment     

L. Eymard  S. Planton  P. Durand  C. Le Visage  P. Y. Le Traon  L. Prieur  A. Weill  D. Hauser  J. Rolland  J. Pelon  F. Baudin  B. Bénech  J. L. Brenguier  G. Caniaux  P. De Mey  E. Dombrowski  A. Druilhet  H. Dupuis  B. Ferret  C. Flamant  P. Flamant  F. Hernandez  D. Jourdan  K. Katsaros  D. Lambert  J. M. Lefèvre  P. Le Borgne  B. Le Squere  A. Marsoin  H. Roquet  J. Tournadre  V. Trouillet  A. Tychensky  B. Zakardjian 《Annales Geophysicae》1996,14(9):986-1015

The SEMAPHORE (Structure des Echanges Mer-Atmosphère, Propriétés des Hétérogénéités Océaniques: Recherche Expérimentale) experiment has been conducted from June to November 1993 in the Northeast Atlantic between the Azores and Madeira. It was centered on the study of the mesoscale ocean circulation and air-sea interactions. The experimental investigation was achieved at the mesoscale using moorings, floats, and ship hydrological survey, and at a smaller scale by one dedicated ship, two instrumented aircraft, and surface drifting buoys, for one and a half month in October-November (IOP: intense observing period). Observations from meteorological operational satellites as well as spaceborne microwave sensors were used in complement. The main studies undertaken concern the mesoscale ocean, the upper ocean, the atmospheric boundary layer, and the sea surface, and first results are presented for the various topics. From data analysis and model simulations, the main characteristics of the ocean circulation were deduced, showing the close relationship between the Azores front meander and the occurrence of Mediterranean water lenses (meddies), and the shift between the Azores current frontal signature at the surface and within the thermocline. Using drifting buoys and ship data in the upper ocean, the gap between the scales of the atmospheric forcing and the oceanic variability was made evident. A 2 °C decrease and a 40-m deepening of the mixed layer were measured within the IOP, associated with a heating loss of about 100 W m⁻². This evolution was shown to be strongly connected to the occurrence of storms at the beginning and the end of October. Above the surface, turbulent measurements from ship and aircraft were analyzed across the surface thermal front, showing a 30% difference in heat fluxes between both sides during a 4-day period, and the respective contributions of the wind and the surface temperature were evaluated. The classical momentum flux bulk parameterization was found to fail in low wind and unstable conditions. Finally, the sea surface was investigated using airborne and satellite radars and wave buoys. A wave model, operationally used, was found to get better results compared with radar and wave-buoy measurements, when initialized using an improved wind field, obtained by assimilating satellite and buoy wind data in a meteorological model. A detailed analysis of a 2-day period showed that the swell component, propagating from a far source area, is underestimated in the wave model. A data base has been created, containing all experimental measurements. It will allow us to pursue the interpretation of observations and to test model simulations in the ocean, at the surface and in the atmospheric boundary layer, and to investigate the ocean-atmosphere coupling at the local and mesoscales.  相似文献   

Book reviews     

Franz Rubel  G. Schauberger 《Theoretical and Applied Climatology》1996,54(3-4):249-250

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Ein weiterer Beitrag zur Vereinfachung der graphischen Integration der barotropen Wirbelgleichung     

Franz Huber-Pock 《Meteorology and Atmospheric Physics》1960,12(1):17-23

Zusammenfassung In einer früheren Arbeit konnte gezeigt werden, daß das durchFjörtoft bei der graphischen Integration des barotropen Modells zur Rückermittlung des Isohypsenfeldes aus der Vorticityverteilung angewandte Näherungsverfahren, dem gewisse die Allgemeinheit einschränkende Voraussetzungen zugrunde liegen, durch eine statistische Methode mit Erfolg ersetzt werden kann. Der vorliegende Bericht beruht auf den gleichen statistischen Grundlagen, es kommen jedoch zusätzlich noch kinematische Überlegungen hinzu, die schließlich zu einer weiteren Vereinfachung des Arbeitsvorganges führen. Auswertungen an einer konkreten Wetterlage zeigen, daß sowohl die statistische wie die statistisch-kinematische Methode darüber hinaus eine gewisse Verbesserung der Resultate der Integration herbeiführen.

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Summary In a previous paper it was shown that the computation of the geopotential field from a given vorticity distribution by means of theFjörtoft method of graphical integration of the barotropic model may be improved by the introduction of statistical considerations. The present paper deals with the same subject, however expanded by kinematical considerations which eventually lead to a further simplification of the routine procedure. The application to an actual weather situation indicates that the statistical as well as the statistical-kinematical method render a certain improvement of the results.

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Résumé Dans une précédente étude, on avait montré que le processus d'approximation deFjörtoft permettant par intégration graphique de restituer le champ d'isohypses et qui supposait certaines restrictions, peut être remplacé avec succès par une méthode statistique. On ajoute ici à cette dernière des considérations d'ordre cinématique qui conduisent à simplifier encore le procédé. Un exemple pratique démontre que l'intégration proposée conduit à des résultats encore meilleurs.

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Bemerkungen zu W. Dammann „Untersuchung über Schwankungen der Winterniederschläge in Deutschland”     

Franz Baur 《Theoretical and Applied Climatology》1960,10(3):422-424

Zusammenfassung An der Methode wird die physikalische Unwirklichkeit der Zusammenfassung der Monate Januar, Februar, März und November und Dezember des gleichen Kalenderjahres als Winter und die Unterdrückung wesentlicher Zusammenhänge mit dem Sonnenfleckenzyklus durch Bildung übergreifender Fünfjahresmittel bemängelt. Hinsichtlich des Ergebnisses wird die behauptete Ähnlichkeit der erhaltenen Kurven mit der Sonnenfleckenwelle widerlegt.

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Summary It is shown that the practice to define the months of January, February, March and November, December of the same calendar year as winter is not justifiable, from a physical point of view. By using running 5-yearly means important relations to the cycle of sun-spots are suppressed. A proposed similarity of the curves obtained byDammann with the solar cycle is disproved.

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Résumé L'auteur montre que l'hiver défini par la période de janvier à mars et de novembre à decembre de la même année est une irréalité physique et que l'emploi de la moyenne mobile de cinq ans masque le cycle des taches solaires; les courbes obtenues parDammann ne correspondent pas rythme des taches.

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Nature et origine des „andésites“ et „trachyandésites“ cénozoiques du Massif Central Français     

Dr. M. Girod  C. Lefèvre 《Contributions to Mineralogy and Petrology》1972,36(4):315-328

The intermediate lavas (andesites, trachyandesites, doreites, sancyites) of the Cenozoïc volcanic districts of the Massif Central (France) are compared with lavas of the alkaline and calc-alkaline suites. On ground of mineralogical and chemical data, two groups may be recognized. The rocks of the first group bear a close resemblance with the intermediate rocks that result of the differentiation of an alkaline basaltic magma. The rocks of the second group, less numerous, possess one or several characters identical to those of calc-alkaline andesites.The contamination suffered by some lavas of both groups has not been sufficient to blot out their comagmatic characteristics.  相似文献   

Le Bassin Cambrien de Tisrouima (Haut-Atlas Occidental,Maroc)     

Henri Termier  Geneviève Termier 《International Journal of Earth Sciences》1971,60(2):656-665

Résumé Dans le Haut-Atlas marocain, entre l'oued Sous au Sud, Asif AÏt Moussa à l'Ouest, le bled Seksaoua au Nord et Tizi n'Test à l'Est, plus exactement dans la partie sud-ouest du Massif du Tichka et au Nord-Ouest de ce massif affleurent en de nombreux endroits des roches charbonneuses: grès, arkoses, pélites, schistes, cipolins et coméennes dont la principale est la tisrouimite (7). Cette dernière s'est déposée un peu avant les calcaires àArchaeocyatha du Cambrien inférieur, puis en mÊme temps que leurs couches de base. Les autres roches charbonneuses sont sensiblement contemporaines de la tisrouimite. On peut en conclure qu'il a existé un bassin sédimentaire riche en matière organique à une époque correspondant, en première approximation, a l'Assadasien.

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The area of study in the moroccan High-Atlas area is included between wady Sous to the South, Asif AÏt Moussa to the West, bled Seksaoua to the North and Tizi n'Test to the East; more exactly it is located in the south-western and nordwestern Tichka. In this area we have noticed numerous outcrops of carbonaceous rocks, such as sandstones, arkoses, mudstones, shales, cipolins and hornfels, the principal variety of which is tisrouimite (7). Tisroumite first was deposited shortly before the Lower Cambrian Archaeocyathid limestones, and again later contemporaneously with the basal layers of these limestones. The other carbonaceous rocks are more or less contemporaneous with the tisrouimite. Therefore we conclude approximately at the time of the Assedasian (early Cambrian II) a sedimentary basin existed the sediments of which were rich in organic matter

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Zusammenfassung Im marokkanischen Hoch-Atlas, zwischen Wadi Sous im Süden, Asif AÏt Moussa im Westen, der Gegend um Seksoua im Norden und Tizi n'Test im Osten, sind im SW-Teil und NE-Teil des Tichka-Gebirgsstockes dunkle, kohlenstoffreiche Gesteine aufgeschlossen: Sandstein, Arkose, Pelit, Schiefer, grüner Marmor und Homfels, dessen Hauptvariante tisrouimite genannt wird. Die Hornfelse sind etwas älter als die Archaeocyathiden-Kalke des Unterkambriums und bilden ihre Basis Die übrigen Gesteine sind etwa gleich alt wie die Hornfelse. Wir schließen daraus, daß hier zur Zeit des Assadassien (tieferes Kambrium II) ein Sedimentationsbecken lag, dessen Sedimente reich an organischen Substanzen waren.

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Bushveld Rooiberg , - , : ) - , ; ) , ; ) , . — , . — , ghoststratigraphy , . — . — , , , Rooiberg, , .

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Comportement géochimique des éléments métalliques en milieu réducteur et diagrammes (log S,pH)     

G. Michard  C. J. Allègre 《Mineralium Deposita》1969,4(1):1-17

Résumé L'existence de relations entre les teneurs en carbonates et en sulfures dans les eaux des bassins réducteurs, ainsi que l'irreversibilité de la réaction sulfate-sulfure, conduisent à proposer le remplacement des diagrammes Eh. pH, par les diagrammes log S, pH (S désignant la concentration totale de S (-II)). Nous donnons ici le principe de construction, des exemples de diagrammes et quelques applications.

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The existence of relations between the amounts of carbonates and the sulfides in the water of anoxic basins and the irreversibility of the reaction sulphate-sulfide lead us to propose the substitution of diagrams Eh, pH by diagrams log S, pH (S being the total concentration of S (-II)). The principle of how diagrams should be drawn is outlined and some examples and applications are given.

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Alters- und Höhengliederung der Karren in den Nördlichen Kalkalpen     

Franz Zwittkovits 《International Journal of Earth Sciences》1968,58(2):378-395

Clints are corrasional features with rock inclined to develop karstic forms which originated by the directed run-off of flowing water. The most typical and far spread features occur in the Northern Calcareous Alps where they are marked by their optimum distribution within the former glaciated areas. With few exceptions, the clints occurring in the Alps are recent. Their age can be established as Late- to Post-Glacial. On the whole the karstic features extend from the highest summits deep down into the valleys but a zone of most extensive distribution occurs between 1900–2000 m and 1200–1300 m. The upper limit is controlled by mechanical weathering, the lower limit by the variation of the conditions of run-off below the soil and vegetation cover. As to ecology the total clint zone can be divided into two areas:

1. The zone of free development of the karst (sharp edged features) and
2. The zone of subcutaneous karst development (rounded features).

With the formation of the clints the rock acts as modifying factor, but the real forming is controlled only by free run-off conditions.  相似文献   

Les caractères magmatiques du volcanisme plio-quaternaire des Andes dans le Sud du Pérou     

C. Lefèvre 《Contributions to Mineralogy and Petrology》1973,41(3):259-272

Chemical data on late cenozoic lavas (83 new analyses) from southern of Peru indicate a zonal arrangement of lavas types according to their distance from the trench. The nearest belong to a calc-alkaline suite and the farthest are shoshonites rocks. The calc-alkaline rocks show progressive increase in K₂O content and in K₂O/Na₂O ratio in northeastern direction. The shoshonitic rocks are more potassic and titaniferous, and the K₂O/Na₂O ratio is approximatively constant. The potash content of the two series correlate with the depth of the inclined seismic zone beneath the volcanoes, but this correlation is less well established than in island arcs.  相似文献   

Spuren auffallend junger Gebirgsbewegungen in den Karawanken     

Franz Kahler 《International Journal of Earth Sciences》1955,43(1):169-174

Zusammenfassung In den Karawanken, die man als jüngstes Gebirge der Ostalpen bezeichnen darf, beobachtet man Hangbrekzien beträchtlichen Ausma\es, deren Absatz unter den heutigen Geländeverhältnissen kaum zu erklären ist. Sie werden einzeln beschrieben und versuchsweise in die Mindel-Ri\-Zwischeneiszeit gestellt.Die Annahme jüngster Verstellungen erleichtert die Erklärung der sonderbaren Lage der Hangbrekzien. Das Gebirge scheint seit jenem Interglazial wesentlich höher geworden zu sein; hierbei spielt der Vorschub gegen Norden eine Rolle.  相似文献