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Particle Dispersion Processes in Two-dimensional Turbulence: a Com...

By: J. M. Redondo; P. J. Gámez-montero; A. Babiano; R. Castilla

Description: LABSON, Dpt. of Fluid Mechanics, U.P.C., Spain. We study numerically the comparison between Lagrangian experiments on turbulent particle dispersion in 2-D turbulent flows performed, on the one hand, on the basis of direct numerical simulations (DNS) and, on the other hand, using kinematic simulations (KS). Eulerian space-time structure of both DNS and KS dynamics are not comparable, mostly due to the absence of strong coherent vortices and advection p...

Babiano, A., Basdevant, C., and Sadourny, R.: Structure functions and dispersion laws in two-dimensional turbulence, J. Atmos. Sci., 42, 942–949, 1985.; Babiano, A., Basdevant, C., Le Roy, P., and Sadourny, R.:. Single particle dispersion, Lagrangian structure function and Lagrangian energy spectrum in two-dimensional incompressible turbulence, J. Mar. Res., 45, 107–131, 1987.; Babiano,A., Basdevant, C., Le Roy, P., and Sadourny, R.: Relative dispersion in two-dimensiona...

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Nonlinear Analysis of Magnetospheric Data Part II. Dynamical Chara...

By: D. Kugiumtzis; E. T. Sarris; N. Hatzigeorgiu; M. A. Athanasiu; D. Diamantidis; G. P. Pavlos

Description: Department of Electrical and Computer Engineering, Demokritos University of Thrace, 67100 Xanthi, Greece. In this study we have used dynamical characteristies such as Lyapunov exponents, nonlinear dynamic models and mutual information for the nonlinear analysis of the magnetospheric AE index time series. Similarly with the geometrical characteristic studied in Pavlos et al. (1999b), we have found significant differences between the original time series a...

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Scaling and Multifractal Fields in the Solid Earth and Topography ...

By: D. Schertzer; S. Lovejoy

Description: Physics, McGill University, 3600 University st., Montreal, Que. H3A 2T8, Canada. Starting about thirty years ago, new ideas in nonlinear dynamics, particularly fractals and scaling, provoked an explosive growth of research both in modeling and in experimentally characterizing geosystems over wide ranges of scale. In this review we focus on scaling advances in solid earth geophysics including the topography. To reduce the review to manageable proportions...

Agterberg, F.: Geomathematics, 596 pp., Elsevier, 1974.; Agterberg, F.: New Applications of the Model of de Wisj in regional geochemistry, Math. Geol., 39, 1–25, doi:10.1007/s11004-006-96063-7, 2007.; Ahrens, L. H.: A fundamental law of geochemistry, Nature, 172, 1148–1152, 1953.; Aitchison, J. and Brown, J. A. C.: The lognormal distribution, with special reference to its uses in economics, 176 pp., Cambridge University Press, 1957.; Aviles, C. A., Scholz, C. H., and Boa...

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Error Growth and Dynamical Vectors During Southern Hemisphere Bloc...

By: J. S. Frederiksen; M. Wei

Description: CSIRO Atmospheric Research, Australia. The structural organization of initially random perturbations or errors evolving in a barotropic tangent linear model with time-dependent basic states taken from observations, is examined for cases of block development, maturation and decay in the Southern Hemisphere atmosphere during April, November and December 1989. We determine statistical results relating the structures of evolved errors to singular vectors (S...

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Projection of Compact Fractal Sets: Application to Diffusion-limit...

By: F. Maggi

Description: Berkeley Water Center, Civil and Environmental Engineering, 413 O'Brien Hall, University of California, Berkeley, CA 94720-1710, USA. The need to assess the three-dimensional fractal dimension of fractal aggregates from the fractal dimension of two-dimensional projections is very frequent in geophysics, soil, and atmospheric sciences. However, a generally valid approach to relate the two- and three-dimensional fractal dimensions is missing, thus question...

Coleman P. and Pietronero L.: The fractal structure of the Universe, Phys. Rep. 213, 311–389, 1992.; Friedlander S. K.: Smoke, Dust and Haze, fundamentals of aerosol behavior. Wiler, New York, 1977.; Grassberger H. G. E. and Procaccia I.: Characterization of strange attractors, Phys. Rev. Lett. 50(5), 346–349, 1983.; Hunt B. R. and Kaloshin V. Y.: How projections affect the dimension spectrum of fractal measures, Nonlinearity 10, 1031–1046, 1997.; Kranenburg C.: On the f...

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Anomalous Width Variation of Rarefactive Ion Acoustic Solitary Wav...

By: S. S. Ghosh; G. S. Lakhina

Description: Indian Institute of Geomagnetism, Kalamboli, New Panvel (W), Navi Mumbai, 410 218, India. The presence of dynamic, large amplitude solitary waves in the auroral regions of space is well known. Since their velocities are of the order of the ion acoustic speed, they may well be considered as being generated from the nonlinear evolution of ion acoustic waves. However, they do not show the expected width-amplitude correlation for K-dV solitons. Recent POLAR...

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Automatic Extraction of Faults and Fractal Analysis from Remote Se...

By: I. Niemeyer; P. R. Marpu; R. Gloaguen

Description: Institute for Geology, Freiberg University of Mining and Technology, 09599 Freiberg, Germany. Object-based classification is a promising technique for image classification. Unlike pixel-based methods, which only use the measured radiometric values, the object-based techniques can also use shape and context information of scene textures. These extra degrees of freedom provided by the objects allow the automatic identification of geological structures. In...

Baker, B. H.: Geology of the Magadi area., Geol. Surv. Kenya Rep., 42, 82 p., 1958.; Baker, B. H., Mitchell, J. G., and Williams L. A. J.: Stratigraphy, geochronology and volcano-tectonic evolution of the Kedong-Naivasha-Kinangop region, Gregory Rift Valley, Kenya, J. Geol. Soc., London, 145, 107–116, 1988.; Barnsley, M.: Fractals everywhere, Academic Press, San Diego, pp 1–117, 1988.; Benz, U. C., Hoffmann, P., Willhauck, G., Lingenfelder, I., and Heynen, M.: Multi-reso...

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Venus Atmosphere Profile from a Maximum Entropy Principle : Volume...

By: C. A. García Canal; H. Fanchiotti; A. F. Pacheco; J. Sañudo; L. N. Epele

Description: Laboratorio de Física Teórica, Departamento de Física, IFLP, Facultad de Ciencias Exactas, Universidad Nacional de La Plata C.C. 67, 1900 La Plata, Argentina. The variational method with constraints recently developed by Verkley and Gerkema to describe maximum-entropy atmospheric profiles is generalized to ideal gases but with temperature-dependent specific heats. In so doing, an extended and non standard potential temperature is introduced that is well...

Bohren, C. F. and Albrecht, B. A.: Atmospheric Thermodynamics, Oxford Univ. Press, 1998.; Callen, H. B.: Thermodynamics, John-Wiley and Sons, p. 323–327, 1980.; Landis, G., Colozza, A., and LaMarre, C.: Atmospheric flight on Venus, NASA-2002-0919, 2002.; Pacheco, A. F. and Sa\~nudo, J.: A maximum entropy profile for the mesosphere, Nuovo Cimento, C28, 29–32, doi:10.1393/ncc/i2005-10021-9, 2005.; Seiff, A., Kirk, D. B., Young, E., et al.: Measurements of Thermal Structure...

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A Hybrid Variational Ensemble Data Assimilation for the High Resol...

By: O. Vignes; J. Bojarova; N. Gustafsson

Description: Swedish Meteorological and Hydrological Institute, 60176 Norrköping, Sweden. A hybrid variational ensemble data assimilation has been developed on top of the HIRLAM variational data assimilation. It provides the possibility of applying a flow-dependent background error covariance model during the data assimilation at the same time as full rank characteristics of the variational data assimilation are preserved. The hybrid formulation is based on an augme...

Berre, L.: Estimation of synoptic and mesoscale forecast error covariances in a limited area model, Mon. Weather Rev., 128, 644–667, 2000.; Berre, L. and Desroziers, G.: Filtering of background error variances and correlations, Mon. Weather Rev., 138, 3693–3720, 2010.; Bishop, C. H., Etherton, B. J., and Majumdar, S. J.: Adaptive Sampling with the Ensemble Transform Kalman Filter, Part I: Theoretical Aspects, Mon. Weather Rev., 129, 420–436, 2001.; Bojarova, J., Gustafss...

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Evolution of Atmospheric Connectivity in the 20Th Century : Volume...

By: M. Barreiro; A. C. Martí; F. Arizmendi

Description: Instituto de Física, Facultad de Ciencias, Universidad de la República, Igua 4225, Montevideo, Uruguay. We aim to study the evolution of the upper atmosphere connectivity over the 20th century as well as to distinguish the oceanically forced component from the atmospheric internal variability. For this purpose we build networks from two different reanalysis data sets using both linear and nonlinear statistical similarity measures to determine the existe...

Albert, R. and Barabási, A. L.: Statistical mechanics of complex networks, Rev. Mod. Phys., 74, 47–97, 2002.; Bandt, C. and Pompe, B.: Permutation entropy: A natural complexity measure for time series, Phys. Rev. Lett., 88, 174102, 2002.; Barab\'asi, A. L. and Albert, R.: Emergence of scaling in random networks, Science, 286, 509–512, 1999.; Barreiro, M.: Influence of ENSO and the South Atlantic Ocean on climate predictability over Southeastern South America, Clim. Dynam...

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Tempting Long-memory - on the Interpretation of Dfa Results : Volu...

By: D. Maraun; H. W. Rust; J. Timmer

Description: Department of Physics, Potsdam University, D-14415 Potsdam, Germany. We study the inference of long-range correlations by means of Detrended Fluctuation Analysis (DFA) and argue that power-law scaling of the fluctuation function and thus long-memory may not be assumed a priori but have to be established. This requires the investigation of the local slopes. We account for the variability characteristic for stochastic processes by calculating empiric...

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Long-term Predictability of Mean Daily Temperature Data : Volume 1...

By: M. Thiel; M. C. Romano; W. Von Bloh

Description: Potsdam Institute for Climate Impact Research, PO Box 60 12 03, 14412 Potsdam, Germany. We quantify the long-term predictability of global mean daily temperature data by means of the Rényi entropy of second order K2. We are interested in the yearly amplitude fluctuations of the temperature. Hence, the data are low-pass filtered. The obtained oscillatory signal has a more or less constant frequency, depending on the geographical coordina...

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Nonstationary Time Series Prediction Combined with Slow Feature An...

By: X. Chen; G. Wang

Description: Key Laboratory of Middle Atmosphere and Global Environment Observations, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China. Almost all climate time series have some degree of nonstationarity due to external driving forces perturbing the observed system. Therefore, these external driving forces should be taken into account when constructing the climate dynamics. This paper presents a new technique of obtaining the drivin...

Berkes, P. and Wiskott, L.: Slow feature analysis yields a rich repertoire of complex cell properties, J. Vision, 5, 579–602, 2005.; Brasseur, G. and Granier, C.: Mount Pinatubo aerosols, chlorofluorocarbons and ozone depletion, Science, 257, 1239–1242, 1992.; Casdagli, M.: Nonlinear prediction of chaotic time series, Phys. D., 35, 335–356, 1989.; Boucharel, J., Dewitte, B., Garel, B., and du Penhoat, Y.: ENSO's non-stationary and non-Gaussian character: the role of clim...

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Kinetic Simulations of the Coupling Between Current Instabilities ...

By: J. Büchner; T. Wiegelmann

Description: Max-Planck Institut für Aeronomie, Max-Planck-Str. 2, 37191 Katlenburg-Lindau, Germany. We investigate the coupling between current and tearing instability modes of a thin current sheet using the particle code GISMO. We identify pure tearing modes (kx≠ 0), instabilities in the current flow direction (ky≠ 0) and general 3D reconnection modes (kx≠ 0 and ky≠ 0). Our results give evidence that the coupling between ...

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Nonlinear Waves and Solitons Propagating Perpendicular to the Magn...

By: K. Sauer; G. Chanteur; J. F. McKenzie; E. M. Dubinin

Description: Max-Planck Institut für Aeronomie, Katlenburg-Lindau, Germany. We investigate the nature of nonlinear waves propagating transverse to the magnetic field in a bi-ion plasma including plasma pressure. By using the conservation laws derived from the multi-ion fluid equations the system may be described by a single order differential equation whose properties control the structure of the flow and the magnetic field. Compressive solitons exist...

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Linear and Nonlinear Modulus Surfaces in Stress Space, from Stress...

By: I. B. Santos; K. R. McCall; R. A. Guyer; G. N. Boitnott; M. Boudjema

Description: Department of Physics, University of Nevada, Reno, USA. The elastic response of many rocks to quasistatic stress changes is highly nonlinear and hysteretic, displaying discrete memory. Rocks also display unusual nonlinear response to dynamic stress changes. A model to describe the elastic behavior of rocks and other consolidated materials is called the Preisach-Mayergoyz (PM) space model. In contrast to the traditional analytic ap...

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Brief Communication: 2-d Numerical Modeling of the Transformation ...

By: X. Shao; Y. Xiao; S. F. Yang; X. M. Xu; W. X. Chen

Description: National Inland Waterway Regulation Engineering Research Center, Chongqing Jiaotong University, Chongqing, 400074, China. This paper investigates the controls on the transformation mechanism among different channel patterns. A 2-D depth-averaged numerical model is applied to produce the evolution of channel patterns with complex interactions among water flow, sediment transport, and bank erosion. Changes of the variables as discharge, sediment supply, a...

Ackers, P. and Charlton, F. G.: The geometry of small meandering streams, Inst. Civ. Eng. Proc., Suppl., xii, 28–317, 1970.; Ashmore, P. E.: Laboratory modeling of gravel braided stream morphology, Earth Surf. Proc., 7, 201–225, 1982.; Ashmore, P. E.: How do gravel-bed rivers braid?, Can. J. Earth Sci., 28, 326–341, 1991.; Beam, R. M. and Warming, R. F.: Factored, a-stable, linear multistep methods: an alternative to the method of lines for multidimensions, ACM Signum Ne...

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Inverse Modelling of Atmospheric Tracers: Non-gaussian Methods and...

By: M. Bocquet

Description: Université Paris-Est, CEREA, Research and Teaching Centre in Atmospheric Environment, Joint laboratory École Nationale des Ponts et Chaussées / EDF R&D, avenue Blaise Pascal, 77455 Champs sur Marne, France. For a start, recent techniques devoted to the reconstruction of sources of an atmospheric tracer at continental scale are introduced. A first method is based on the principle of maximum entropy on the mean and is briefly reviewed here. A second approac...

Bocquet, M.: Grid resolution dependence in the reconstruction of an atmospheric tracer source, Nonlin. Processes Geophys., 12, 219–234, 2005a.; Bocquet, M.: Reconstruction of an atmospheric tracer source using the principle of maximum entropy, I: Theory, Q. J. Roy. Meteor. Soc., 131, 2191–2208, 2005b.; Bocquet, M.: Reconstruction of an atmospheric tracer source using the principle of maximum entropy, II: Applications, Q. J. Roy. Meteor. Soc., 131, 2209–2223, 2005c.; Bocq...

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Accurate Estimation of Third-order Moments from Turbulence Measure...

By: M. A. Forman; C. W. Smith; D. C. Elton; Y. Gagne; Y. Malécot; J. J. Podesta

Description: Space Science Center, University of New Hampshire, Durham, New Hampshire, 03824, USA. Politano and Pouquet's law, a generalization of Kolmogorov's four-fifths law to incompressible MHD, makes it possible to measure the energy cascade rate in incompressible MHD turbulence by means of third-order moments. In hydrodynamics, accurate measurement of third-order moments requires large amounts of data because the probability distributions of velocity-difference...

Balogh, A., Beek, T J., Forsyth, R J., Hedgecock, P C., Marquedant, R J., Smith, E J., Southwood, D J., and Tsurutani, B T.: The magnetic field investigation on the ULYSSES mission - Instrumentation and preliminary scientific results, Astron. Astrophys.\ Suppl. Ser., 92, 221–236, 1992.; Belcher, J W. and Davis, L.: Large-amplitude Alfvén waves in the interplanetary medium, 2., J Geophys. Res., 76, 3534–3563, 1971.; Dudok de Wit, T.: Can high-order moments be meaningfully...

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Non-stationary Temporal Characterization of the Temperature Profil...

By: L. E. Parent; A. Pratte; M. A. Bolinder; F. Anctil

Description: Department of Civil Engineering, Université Laval, Québec, Canada. The objective of this work was to compare time and frequency fluctuations of air and soil temperatures (2-, 5-, 10-, 20- and 50-cm below the soil surface) using the continuous wavelet transform, with a particular emphasis on the daily cycle. The analysis of wavelet power spectra and cross power spectra provided detailed non-stationary accounts with respect to frequencies (or periods) and...

Anctil, F. and Coulibaly, P.: Wavelet analysis of the interannual variability in southern Québec streamflow, J. Climate, 17, 163–173, 2004.; Andrén, O. and Kätterer, T.: ICBM: The Introductory Carbon Balance Model for exploration of soil carbon balances, Ecol. Appl., 7, 1226–1236, 1997.; Bartlett, M. G., Chapman, D. S., and Harris, R. N.: A decade of ground-air temperature tracking at Emigrant Pass observatory, Utah, J. Climate, 19, 3722–3731, 2006.; Beltrami, H. and Mar...

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