ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Analysis of rainfall variability in the northeastern region of South Africa (1983)
    Springer
    Meteorology and atmospheric physics 32 (1983), S. 231-252 
    Details
    ISSN: 1436-5065
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Description / Table of Contents: Zusammenfassung Die mittleren monatlichen und jährlichen Regenfallsreihen (1930–1977) für ein 30×30 Bogenminuten-Netz im östlichen Transvaal und Swaziland wurden analysiert. Diese Reihen zeigen eine charakteristische zeitliche und räumliche Veränderlichkeit des Niederschlagsregimes, deren Signifikanz auf quasi-periodische Anregung mit Perioden von ungefähr 16–20 Jahren und 13–14 Monaten, im gesamten Gebiet evident, zurückgeführt werden kann. Schwingungen im Bereich eines quasi-biennalen Zykluses wurden ebenfalls beobachtet, jedoch mit geringerer Signifikanz. Eine Analyse der Hauptkomponenten ergibt eine Anzahl von Eigenvektoren, welche mit den Änderungen im jahreszeitlichen Charakter des regionalen Niederschlages identifiziert werden können. Der Jahresgang dominiert eindeutig in der gesamten Region, wobei Januar (Mittsommer) der nasseste Monat ist. Der zweite Eigenvektor besitzt hohe Amplituden im Frühling und Frühsommer (November) und zeigt eine räumliche Verteilung, die auf topographisch induzierte Unterschiede in den Konvektionsprozessen dieses Gebietes zurückzuführen ist. Die Hauptkomponenten höherer Ordnung sind in ihrer zeitlichen Struktur nicht eindeutig definiert. Der dritte Eigenvektor kann jedoch zum Teil auf synoptische Vorgänge bezogen werden, welche in den Küstenebenen und im Plateau des Hinterlandes verschiedene Niederschlagsvertefungen bewirken.
    Notes: Summary The mean monthly and annual rainfall series (1930–1977) for 30×30 blocks in the eastern Transvaal-Swaziland region ara analyzed. These series show temporal and spatial characteristics in the regional precipitation regime. Significance is attributed to oscillatory forcings with quasi-periodicities of about 16–20 years and 13–14 months that operate throughout the area. Oscillations near the quasi-biennial cycle are also observed but with less significance. Principal component analysis provides a number of eigenvectors which are identified with changes in the seasonal characteristics of the regional rainfall. The annual cycle clearly dominates over the entire region with January (mid-summer) being the wettest month. The second eigenvector has pronounced loadings in the spring/early summer (November) period and clear spatial responses that are attributed to topographically induced differences in the deep convective processes of the area. Higher principal components are not as clearly defined in their temporal structure. The third eigenvector, however, is attributed partially to synoptic scale forcings which produce different rainfall characteristics over the coastal plains relative to the high inland plateau.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02273976
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Convective cloud downdrafts as the cause of large blowdowns in the Amazon rainforest (1998)
    Springer
    Meteorology and atmospheric physics 67 (1998), S. 199-212 
    Details
    ISSN: 1436-5065
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Summary Nelson et al. (1994) report a non-uniform distribution of large (0.33 to 33 km2) blowdowns in the rainforests of Amazonia. Occurrence of such large disturbances in the wet, low wind speed regime of the Amazon Basin cannot be explained by conventional mechanisms such as fire or hurricanes. While downdrafts from deep convective clouds are likely candidates, this paper draws upon meteorological observations from the central Amazon Basin to show that the requisite magnitudes of wind speed can be reached but only under conditions which would explain the observed horizontal distributions of the large blowdowns. Outflow velocities due to density driven downdrafts in the convective clouds are shown from observations to reach 15 m/s and correspond to the propagation velocities of longlived Amazon squall lines. Maintenance over 48 h of these squall lines depends upon the correspondence between the outflow velocity and the propagation velocity. The storms propagate within a basic current moving at 5 m/s, increasing the outflow velocities to 21 m/s. The development of a storm-generated pressure field must be called upon to increase the magnitude of the density and basic currents to more than 30 m/s. Such conditions occur only when the convection is embedded in squall lines which reach their diurnal maximum at locations nearly coincident with the observed locations of the maxima in large blowdowns. The characteristics of the observed blowdowns in terms of orientation, size and shape are consistent with winds derived from the postulated downward moving density currents being deflected and accelerated orthogonally at canopy top and forest floor. The causes and distribution of large blowdowns in the wet, low wind regime of the Amazon rainforest are shown to be important in explaining the disturbance regime of that system. Such disturbances are necessary in maintaining diversity of the system by locally disrupting the canopy, altering levels of incident radiation received at the surface and changing patterns of nutrient cycling, carbon uptake and storage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01277510
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The role of convection in surface property and velocity fluctuations (1974)
    Springer
    Boundary layer meteorology 6 (1974), S. 183-195 
    Details
    ISSN: 1573-1472
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Time series of temperature, humidity and horizontal wind speed are presented from data collected at two tower sites during the 1968 Barbados Experiment. Marked and periodic fluctuations on the convective scale are evident in the traces. It is postulated that these fluctuations are due to moderate cumulus convection. Estimates show that departures in temperature and humidity at the surface must be due to downward mixing from near or above the convective cloud base. Such cloud layer-subcloud layer mixing must change the thermodynamic character of the subcloud layer. This in turn suggests that cloud convection may play an important part in governing the transport of energy across the air-sea interface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00232483
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Wave spectra with directional aspects from deep water in the tropical Atlantic (1972)
    Springer
    Ocean dynamics 25 (1972), S. 164-178 
    Details
    ISSN: 1616-7228
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Description / Table of Contents: Zusammenfassung Im Juli und August 1968 wurden Wellenhöhen mit einem System von 3 Wellendrähten gemessen, die an einer im tiefen Wasser östlich von Barbados verankerten großen Spierentonne befestigt waren. Die Bewegungen der Tonne wurden gleichzeitit mit Beschleunigungsmessern gemessen und die Bewegungsmessungen wurden dazu benutzt, die gemessenen Wellenhöhen zu korrigieren. Ungefähr 550 Stunden von Wellendaten wurden registriert und automatisch gleichzeitig meteorologische Beobachtungen. Spektren wurden für die besten 292 Daten-Stunden errechnet. Es stellte sich heraus, daß die Wellenänderung als Funktion der Windgeschwindigkeit sich ändert mit der 5,4ten Potenz der Windgeschwindigkeit.
    Abstract: Résumé La hauteur des vagues dans l'Atlantique tropical a été mesurée à l'aide d'un réseau de 3 câbles fixés à une grosse bouée spar ancrée en eau profonde, à l'est de Barbade de juin à août 1968. Les mouvements de la bouée ont été mesurés de façon cohérente avec des accéléromètres, et les mesures de mouvements utilisées pour corriger les hauteurs mesurées pour les vagues. On a enregistré approximativement 550 heures de données sur les vagues et d'observations météorologiques automatiques cohérentes. Les spectres ont été calculés pour les 292 meilleures heures de mesure; la variance des vagues, en fonction de la vitesse du vent a été estimée comme proportionnelle à la puissance 5,4 de la vitesse du vent.
    Notes: Summary Wave heights were measured with an array of three wave wires attached to a large spar buoy anchored in deep water east of Barbados in July and August 1968. Buoy motions were measured coherently with accelerometers and motion measurements used to correct measured wave heights. Approximately 550 h of wave data and coherent automatic meteorological observations were recorded. Spectra were calculated for the best 292 h of data. The wave variance as a function of wind speed was found to vary as the 5.4 power of the wind speed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02312701
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Comparison of sensible and latent heat fluxes computed from measurements by ship and spar buoy in the tropical Atlantic ocean (1972)
    Springer
    Ocean dynamics 25 (1972), S. 62-79 
    Details
    ISSN: 1616-7228
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Description / Table of Contents: Zusammenfassung Es wird berichtet über Berechnungen der wahrnehmbaren und latenten Wärmeströmungen anhand von Messungen, die im Juli und August 1968 von einem Schiff aus sowie von einer Spierenboje östlich von Barbados vorgenommen worden sind. Ein ausführlicher Vergleich der täglichen Variation der Wärmeströmungen zeigt, daß das Schiff eine. Insel der Turbulenz schafft, mit ganz anderen Verhältnissen als denen auf offener See. Von der Boje aus erfolgte Messungen, von denen man annimmt, daß sie typischer sind für die Verhältnisse auf offener See, zeigen, daß die konstante Schicht des Wärmestromes weniger als 6 m dick sein kann.
    Abstract: Résumé Il est rendu compte des calculs de flux de chaleur sensible et latente tirés de mesures effectuées par un navire et par une bouée espar dans l'Est de la Barbade en juillet et août 1968. Une comparaison détaillée de la variation diurne de flux, montre que le navire crée une île de turbulence où les conditions diffèrent complètement de celles d'une mer libre. Les mesures prises par la bouée, considérées comme se rapprochant mieux des conditions en mer libre, montrent que l'épaisseur de la couche de flux constant peut être inférieure à 6 m.
    Notes: Summary Computations of sensible and latent heat fluxes from measurements taken aboard a ship and from a spar buoy east of Barbados in July and August, 1968 are reported. A detailed comparison of the diurnal variation of the fluxes shows that the ship creates an island of turbulence quite different from open sea conditions. Measurements from the buoy, which are believed to be more typical of open ocean conditions indicate that the constant flux layer may be less than 6 m thick.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02226287
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Downdrafts from tropical oceanic cumuli (1984)
    Springer
    Boundary layer meteorology 28 (1984), S. 23-49 
    Details
    ISSN: 1573-1472
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Simultaneous observations at up to six levels through a depth of 1100 m from a tethered balloon and instrumented ship's boom of 49 gust fronts associated with convective clouds are used to describe the mean and the detailed characteristics of tropical oceanic cumuli outflow at the surface and in the boundary layer. The changes in temperature and velocity of the maritime tropical gust front are about 50%; of the changes observed in mid-latitude convective outflows. Vertical velocities at the gust front ⩾l m s-1 are continuous through the lower 500 m for time periods up to 8 min implying vertical displacements of at least 500 m entirely sufficient at the observed humidities (q 〉- 15 g kg-1) to initiate new cloud growth. Horizontal and vertical vorticity in the order of 10-3 s-1 to 10-2 s-1 is observed at the gust front.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00119455
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Use of a synoptic classification scheme to define seasons (1987)
    Springer
    Theoretical and applied climatology 38 (1987), S. 57-68 
    Details
    ISSN: 1434-4483
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Description / Table of Contents: Zusammenfassung Diese Arbeit stellt ein synoptisches Klassifikationsschema nach Bodenwetterkarten vor, das eine Kategorisierungstechnik verwendet, um die Jahreszeiten meteorologisch zu definieren. Der Winter ist als die Periode des Jahres festgelegt, in der ein Ort meist polwärts der Polarfront, während der Sommer jene Periode ist, in der er äquatorwärts der Polarfront liegt. Herbst und Frühjahr sind die Übergangsperioden, in denen zunehmend häufigere bzw. weniger häufige Abschnitte polwärts der Polarfront vorkommen. Die Anwendung dieser Jahreszeitendefinition wird mit Hilfe der Daten aus 10 Jahren für die Atlantik- und Golfküste der Vereinigten Staaten vorgestellt. Während die Häufigkeiten bestimmter Wetterlagen mit der geographischen Breite schwanken, erwies sich diese meteorologische Jahreszeitendefinition demgegenüber als vergleichbar invariant (mit einem maximalen Unterschied von einem Monat) innerhalb des ausgewählten Gebiets. Der so definierte Winter dieser Region beginnt zwischen Ende Oktober und Anfang November und dauert bis Ende März bzw. Anfang April. Sommer ist zwischen Ende Mai/Anfang Juni und Ende August/Ende September.
    Notes: Summary This paper presents a synoptic surface weather map classification scheme, and uses the categorization technique to meteorologically define seasons. Winter is defined as that period of the year in which a location is most frequently poleward of the polar front, while summer occurs when the site is most commonly equatoward. Fall and Spring are the transition periods when, respectively, increasingly more frequent and less frequent periods of time poleward of the polar front occur. Using 10 years of data, the application of this definition of seasons to the Gulf and Atlantic coasts of the United States is presented. While the frequency of the specific types of major synoptic weather features varied with latitude, the meteorological definitions of season are comparatively invariant with latitude (differing by no more than a month) for this geographic area. Using the meteorological definitions of season, the average winter for this region occurs from late October or early November to late March or early April. Summer is from late May to early June until late August or late September.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00868418
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Combined application of INAA and PIXE for studying the regional aerosol composition in Southern Africa (1997)
    Springer
    Journal of radioanalytical and nuclear chemistry 216 (1997), S. 143-148 
    Details
    ISSN: 1588-2780
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract As part of the SAFARI-92 biomass buming experiment, aerosol collections were carried out with several size-fractionating sampling devices at a number of sites in Southern Africa. One of the samplers used at all ground-based sites was a stacked filter unit (SFU). The SFU samples were analyzed by both INAA and PIXE analysis. The present paper gives an intercomparison of the analytical results obtained in order to assess the accuracy and to check the quality assurance of the analytical procedures. Twenty-one common elements were determined by both INAA and PIXE. Concentrations of 13 elements (i.e., Na, Mg, Al, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Zn and Br) were generally measured with sufficient precision in both techniques for performing the intercomparison. The INAA and PIXE data were compared in terms of PIXE/INAA concentration ratios on a sample by sample basis for the coarse and fine size fraction separately. the atmospheric concentrations for K, Mn and Fe agreed within 5–10%, the agreement between the data for the other common elements was typically better than 15%. Possible explanations for lower than 1.0 ratios for Cl, Br and Na are presented. The common elements were classified into groups according to their detectability and sensitivity in each technique.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02034512
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    facet.materialart.
    Unknown
    The Research of Dr. Joanne Simpson: Fifty Years Investigating Hurricanes, Tropical Clouds, and Cloud Systems (2003)
    American Meteorological Society
    Details
    Publication Date: 2003-01-01
    Print ISSN: 0065-9401
    Electronic ISSN: 1943-3646
    Topics: Geography , Geosciences , Physics
    Published by American Meteorological Society
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    The role of convection in surface property and velocity fluctuations (1974)
    Springer
    Details
    Publication Date: 1974-03-01
    Print ISSN: 0006-8314
    Electronic ISSN: 1573-1472
    Topics: Geosciences , Physics
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...