Four thousand years of atmospheric lead pollution in northern Europe: a summary from Swedish lake sediments   总被引：8，自引：7，他引：8  

M.-L. Bränvall  R. Bindler  O. Emteryd  I. Renberg 《Journal of Paleolimnology》2001,25(4):421-435

This paper presents a large palaeolimnological study of the pre-industrial and industrial history of atmospheric lead pollution deposition in Sweden. Both lead concentrations and ²⁰⁶Pb/²⁰⁷Pb ratios have been analysed in 31 lakes covering most of Sweden, plus one lake in north-west Russia. Four of the lakes have varved (annually-laminated) sediments. Isotope analysis is a sensitive and effective method to distinguish pollution lead from natural catchment lead and to detect early pollution influence, because the ²⁰⁶Pb/²⁰⁷Pb ratio in unpolluted background sediments in Sweden was > 1.3, while that of lead from pollution, derived from ores and coal, was < 1.2. The sediments show a consistent picture of past temporal changes in atmospheric lead pollution. These changes include: the first traces of pollution 3,500-3,000 yrs ago; a pollution peak in Greek-Roman Times (about 0 AD); lower lead fall-out between 400 and 900 AD; a significant and permanent increase in atmospheric lead fall-out from about 1000 AD; an increase with the Industrial revolution; a major increase following World War II; the maximum peak in the 1970s; and decreasing fall-out over the last decades. The four varved sediments provide high-resolution records of atmospheric pollution. They reveal pollution peaks about 1200 and 1530 AD which match the history of metal production in Europe. According to the varve records the lead pollution level in the late 1990s had decreased beneath the level of the 1530s. The pollution level 1200 AD was about 35% of the 1980s, when lead pollution was still near its all time high. About 50% of the total accumulated atmospheric lead pollution deposition through time was deposited in the pre-industrial period. The sediments also show a consistent picture of the geographic distribution of atmospheric lead deposition over time, with higher deposition in south Sweden and declining levels to the north, which supports the hypothesis that the main sources of pre-industrial atmospheric lead pollution in Sweden were cultural areas in mainland Europe and Great Britain.  相似文献   

Surface NO and NO2 mixing ratios measured between 30° N and 30° S in the Atlantic region     

F. Rohrer  D. Brüning 《Journal of Atmospheric Chemistry》1992,15(3-4):253-267

Surface NO and NO₂ mixing ratios were measured aboard the research vessel Polarstern during the mission ANT VII/1 from 24 September to 5 October 1988. The measurements were taken along the meridian at 30° W in the Atlantic region covering latitudes between 30° N and 30° S. The average mixing ratios were about 12 pptv NO/30 pptv NO₂ in the Northern Hemisphere and about 7 pptv NO/22 pptv NO₂ in the Southern. Elevated mixing ratios of 20 pptv NO/70 pptv NO₂ were found at 12° N (probably due to air masses originating from the surface of West Africa) and in the region of the ITCZ between 8° N and 5° N. Because of probable contamination by the ship, the measured mixing ratios mostly represent upper limits.  相似文献   

The fog front of 25 May 1989 — A gravity flow?     

B. Hennemuth  A. Rhodin  B. Brümmer 《Meteorology and Atmospheric Physics》1992,48(1-4):273-292

Summary During the field experiment FRONTEX 1989 a shallow cold front with a fog field behind its leading edge was observed over the North Sea. The fog field was about 70 km wide, 160 m deep at the front side and 400 m deep at the rear side and was capped by a strong frontal inversion. With increasing height of the inversion the fog broke up into cumulus clouds. The horizontal temperature gradient was largest at 500 m with 9 K/100 km. The observed segment of the front was situated near the col of a geostrophic deformation field with vanishing cross-front wind but non-vanishing cross-front confluence. The front moved at a rate of 5 m/s. It exhibits characteristics of a gravity current which propagates into a stably stratified environment.The physical processes leading to the observed frontal structure and motion are elucidated by experiments with a two-dimensional numerical model. The charateristics of the observed front can be reproduced if both, geostrophic forcing and boundary-layer processes, such as air-sea temperature difference, moisture content and cloud radiational cooling are taken into account. The development of the front under altered conditions is studied by the comparison of different simulations. The reason for the movement of the front is discussed refering to the mechanisms of geostrophic forcing and the forcing by surface friction. The analysis of the forces acting on the cold air mass shows that the Coriolis force is important at some distance behind the frontal head, but has little effect on the processes at the frontal head.With 13 Figures  相似文献   

Der Jahresverlauf der Zyklonalen und Antizyklonalen Aktivität auf der Nordhemisphäre     

Jan Brádka 《Studia Geophysica et Geodaetica》1957,1(2):342-371

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The mantle rock (“laterite”) of the Gold Coast and its origin     

Werner Brückner 《International Journal of Earth Sciences》1955,43(2):307-327

Zusammenfassung Der Verwitterungsmantel (Laterit s. l.) der südlichen Goldküste besteht aus Horizonten, die sowohl verschiedene Entstehungsart als verschiedenes Alter haben. Brekzien oder Steinschichten sind unter aridem Klima als Wüstenpflaster entstanden. Zonen chemisch verwitterten Felses, Horizonte von lehmigem Sand (an deren Aufbau Termiten wesentlich beteiligt sind) und Konkretionen haben sich unter feuchtem Klima gebildet. Harte limonitische Oberflächen-Krusten deuten auf progressive Austrocknung hin. Unter diesen drei klimatischen Bedingungen gebildete Horizonte wiederholen sich mehrfach im Verwitterungsmantel der Goldküste. Ein junger, unvollständiger Zyklus ist weit verbreitet, ein älterer Zyklus tritt nur in begrenzten Vorkommen auf, und ein dritter Zyklus ist fast nur noch in aufgearbeiteten, limonitisierten Bruchstücken erhalten. Die wiederholten Klimaschwankungen machen es wahrscheinlich, daß der Verwitterungsmantel zeitlich dem größeren Teil des Quartärs entspricht. Wahrscheinlich können die Ergebnisse auf weit größere Gebiete angewandt werden.  相似文献   

Daily Weather Observations in Sixteenth-Century Europe     

Christian Pfister  Rudolf Brázdil  Rüdiger Glaser  Anita Bokwa  Franz Holawe  Danuta Limanowka  Oldřich Kotyza  Jan Munzar  Lajos Rácz  Elisabeth Strömmer  Gabriela Schwarz-Zanetti 《Climatic change》1999,43(1):111-150

Thirty-two weather diaries written in astronomical calendars in central Europe in the late fifteenth and sixteenth centuries are presented and discussed. Systematic weather observations were promoted by the rise of planetary astronomy and its application in astro-meteorology. The practice of keeping weather diaries spread from Cracow (Poland) to Ingolstadt (Germany) and from there to other universities. The data obtained from these sources provided the backbone for setting up series of precipitation indices for Poland, Germany and Switzerland. Monthly statistics of days with precipitation, snowfall and frost were computed by counting the relevant entries in the most important diaries. The results were compared with either those obtained from instrumental measurements in the same place or with those from modern instrumental measurements in a neighbouring place. The final results show that autumn was considerably colder in the early sixteenth century. April was considerably drier and July was wetter during the period 1508-1531 than during 1901-1960. In order to highlight the impact of weather patterns on grain prices in a year of crisis, the timing of wet and dry spells in southern Poland and southern Germany is compared for the year 1529. Winters became 1.7°C colder from 1564 to 1576 and the month of July tended to be wetter than in 1901-1960. Details noted in the diaries kept between 1585 and 1600 by the astronomers Brahe (near Copenhagen) and Fabricius (in the Ostfriesland region of northwestern Germany) closely agree. It rained more often in June and July and temperatures dropped. The winter months were more frequently dominated by winds from easterly directions, the frequency of snowfall was higher and a deficit occurred in precipitation. This points to a higher frequency of high pressure in the Fennoscandian area with cold air advection from the east or northeast.  相似文献   

Climate in the Czech Lands during the 1780s in Light of the Daily Weather Records of Parson Karel Bernard Hein of Hodonice (Southwestern Moravia): Comparison of Documentary and Instrumental Data   总被引：1，自引：1，他引：0  

Rudolf Brázdil  Hubert Valášek  Jarmila Macková 《Climatic change》2003,60(3):297-327

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Chemical ozone loss in the Arctic vortex in the winter 1995–96: HALOE measurements in conjunction with other observations     

R. Müller  J.-U. Grooß  D. S. McKenna  P. J. Crutzen  C. Brühl  J. M. Russell III  L. L. Gordley  J. P. Burrows  A. F. Tuck 《Annales Geophysicae》1998,17(1):101-114

Severe chemical ozone loss has been detected in the Arctic in the winter and spring of 1995–96 by a variety of methods. Extreme reductions in column ozone due to halogen catalysed chemistry were derived from measurements of the Halogen Occultation Experiment (HALOE) on board the Upper Atmosphere Research Satellite in the Arctic vortex. Here, we discuss further aspects of the HALOE observations in the Arctic over this period. Potential problems, both in the data themselves and in the methodology of the data analysis are considered and the reason for the differences between the Arctic ozone losses deduced from HALOE data version 17 and 18 is analysed. Moreover, it is shown that HALOE measurements in the Arctic in winter and spring 1995–96 compare well with observations by other ground-based and satellite instruments.  相似文献   

Geography of contamination: The location of industrial waste dumps in Catalonia     

M. Angels Alió  J. Brú 《GeoJournal》1990,22(4):429-437

The handling of the solid industrial waste (SIW) generated in Catalonia is one of the main problems of industrial and territorial policy confronting the public bodies controlling this area of activity. The most recent estimates in this regard indicate that the annual production of SIW is 1,700,000 tons and that only 300,000 tons are treated.In this situation it is usual for a large number of industries to eliminate their SIW furtively, it is common practice to dump waste in various unprepared areas. In this article we present a series of hypotheses which we believe allow us to understand the logic that guides the siting of a large number of these dumps.In the first place we demonstrate the importance of a series of conditions derived from the same industrial logic, to wit, a) the cost of transporting the SIW to the dumps, b) the industrial decentralization process and the metropolitan development of Catalonia, c) vertical integration and the appearance of companies especially dedicated to the elimination of waste and, d) the development of land use through revaluation of the land and greater possibilities for control forces furtive dumps to be sited in more and more distant areas.Secondly, we examine the role of public bodies in this process, concentrating on the characteristics of the legal system and the real effectiveness of urban controls. Finally, in third place, an explanation is given of research carried out in the Barcelona area which shows the importance of the conditions examined above.  相似文献   

Zur Glazialgeologie der chilenischen Anden     

J. Brüggen 《International Journal of Earth Sciences》1929,20(1):1-35

Ohne Zusammenfassung  相似文献