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Characterizing Water Fingering Phenomena in Soils Using Magnetic R...

By: S. Crestana; A. Tannús; R. Quiroz; C. M. Vaz; A. Posadas

Description: International Potato Center – CIP, P.O. Box 1558, Lima 12, Peru. The study of water movement in soils is of fundamental importance in hydrologic science. It is generally accepted that in most soils, water and solutes flow through unsaturated zones via preferential paths or fingers. This paper combines magnetic resonance imaging (MRI) with both fractal and multifractal theory to characterize preferential flow in three dimensions. A cubic double-layer col...

Amin, M. H. G., Hall, L. D., Chorley, R. J., and Richards, K. S.: Infiltration into soils, with particular reference to its visualization and measurement by magnetic resonance imaging(MRI), Prog. Phys. Geog., 22(2), 135–165, 1998.; Beck, C. and Schlogl, F.: Thermodynamics of Chaotic Systems: An introduction. Cambridge Nonlinear Science Series 4, Cambridge University Press, 306~pp., 1995.; Brown, J. M., Kramer, P. J., Cofer, G. P., and Johnson, G. A.: Use of nuclear magne...

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Comment on Multivariate Non-normally Distributed Random Variables ...

By: F. Serinaldi

Description: Dipartimento di Idraulica Trasporti e Strade, Sapienza Università di Roma, Via Eudossiana 18, 00184 Rome, Italy. No abstract available.

Bárdossy, A.: Copula-based geostatistical models for groundwater quality parameters, Water Resour. Res., 42, W11416, \doi10.1029/2005WR004754, 2006.; dos Santos Silva, R. and Freitas Lopes, H.: Copula, marginal distributions and model selection, Stat. Comput., 18, 313–320, 2008.; Drouet-Mari, D. and Kotz, S.: Correlation and dependence, Imperial College Press, London, 2001.; Fang, H B., Fang, K T., and Kotz, S.: The meta-elliptical distributions with given marginals, J. ...

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Substorm Classification with the Windmi Model : Volume 10, Issue 4...

By: D. Vassiliadis; R. S. Weigel; I. Doxas; W. Horton

Description: The University of Texas at Austin, Austin, TX 78712, USA. The results of a genetic algorithm optimization of the WINDMI model using the Blanchard-McPherron substorm data set is presented. A key result from the large-scale computations used to search for convergence in the predictions over the database is the finding that there are three distinct types of vx Bs -AL waveforms characterizing substorms. Type I and...

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Anisotropic Scaling Features and Complexity in Magnetospheric-cusp...

By: M. Kretzschmar; G. Consolini; B. Popielawska; A. W. Wernik; M. Materassi; M. Roca-sogorb; J. Bergman; E. Yordanova; K. Stasiewicz

Description: Space Research Center, Polish Academy of Sciences, Warsaw, Poland. Magnetospheric cusps are high-latitude regions characterized by a highly turbulent plasma, playing a special role in the solar wind-magnetosphere interaction. Here, using POLAR satellite magnetic field vector measurements we investigate the anisotropic scaling features of the magnetic field fluctuations in the northern cusp region. Our results seem to support the hypothesis of a 2D-MHD tu...

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North Atlantic Climate Variability in Coupled Models and Data : Vo...

By: P. S. Berloff; M. Ghil; W. K. Dewar; J. C. McWilliams; S. K. Kravtsov

Description: Department of Mathematical Sciences, University of Wisconsin-Milwaukee, P. O. Box 413, Milwaukee, WI 53201, USA. We show that the observed zonally averaged jet in the Northern Hemisphere atmosphere exhibits two spatial patterns with broadband variability in the decadal and inter-decadal range; these patterns are consistent with an important role of local, mid-latitude ocean–atmosphere coupling. A key aspect of this behaviour is the fundamentally nonlinea...

Allen, R. M. and Smith, L. A.: Monte Carlo SSA: Detecting irregular oscillations in the presence of colored noise, J. Climate, 9, 3373–3404, 1996.; Allen, M. R. and Robertson, A. W.: Distinguishing modulated oscillations from coloured noise in multivariate data sets, Clim. Dynam., 12, 775–784, doi:10.1007/s003820050142, 1996.; Broomhead, D. S. and King, G. P.: Extracting qualitative dynamics from experimental data, Physica D, 20, 217–236, 1986.; Berloff, P.: On rectifica...

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The Small Amplitude of Density Turbulence in the Inner Solar Wind ...

By: S. R. Spangler

Description: University of Iowa, USA. Very Long Baseline Interferometer (VLBI) observations were made of radio sources close to the Sun, whose lines of sight pass through the inner solar wind (impact parameters 16-26 RE). Power spectra were analyzed of the interferometer phase fluctuations due to the solar wind plasma. These power spectra provide information on the level of plasma density fluctuations on spatial scales of roughly one hu...

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Nonlinear Time Series Analysis of Geomagnetic Pulsations : Volume ...

By: J. Kristek; Z. Vörös; J. Verö

Description: Geophysical Institute SAS, 94701 Hurbanovo, Slovakia. A detailed nonlinear time series analysis has been made of two daytime geomagnetic pulsation events being recorded at L'Aquila (Italy, L ≈ 1.6) and Niemegk (Germany, L ≈ 2.3). Grassberger and Procaccia algorithm has been used to investigate the dimensionality of physical processes. Surrogate data test and self affinity (fractal) test have been used to exclude coloured noise with power law spectra. La...

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Wave Turbulence in Magnetized Plasmas : Volume 16, Issue 1 (16/02/...

By: S. Galtier

Description: Institut d'Astrophysique Spatiale, bâtiment 121, Université Paris-Sud XI, UMR 8617, 91405 Orsay, France. The paper reviews the recent progress on wave turbulence for magnetized plasmas (MHD, Hall MHD and electron MHD) in the incompressible and compressible cases. The emphasis is made on homogeneous and anisotropic turbulence which usually provides the best theoretical framework to investigate space and laboratory plasmas. The solar wind and the coronal he...

Abdurakhimov, L. V., Brazhnikov, M. Y., and Levchenko, A. A.: Statistic of capillary waves on the surface of liquid hydrogen in a turbulent regime, J. Low Temp. Phys., 150, 431–434, 2008.; Alexakis, A., Bigot, B., Politano, H., and Galtier, S.: Anisotropic fluxes and nonlocal interactions in magnetohydrodynamic turbulence, Phys. Rev. E., 76, 056313, doi:10.1103/PhysRevE.76.056313, 2007.; Alexakis, A., Mininni, P. D., and Pouquet, A.: Shell-to-shell energy transfer in mag...

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Electron Acoustic Solitons in the Presence of an Electron Beam and...

By: G. S. Lakhina; S. V. Singh; R. Bharuthram; S. Devanandhan

Description: Indian Institute of Geomagnetism, New Panvel (West), Navi Mumbai, India. Arbitrary amplitude electron acoustic solitons are studied in an unmagnetized plasma having cold electrons and ions, superthermal hot electrons and an electron beam. Using the Sagdeev pseudo potential method, theoretical analysis is carried out by assuming superthermal hot electrons having kappa distribution. The results show that inclusion of an electron beam alters the minimum va...

Armstrong, T. P., Paonessa, M. T., Bell II, E. V., and Krimigis, S.M.: Voyager observations of Saturnian ion and electron phase space densities, J. Geophys. Res., 88, 8893–8904, 1983.; Berthomier, M., Pottelette, R., Malingre, M., and Khotyaintsev, Y.: Electron-acoustic solitons in an electron-beam plasma system, Phys. Plasmas, 7, 2987–2994, 2000.; Berthomier, M., Pottelette, R., Muschietti, L., Roth, I., and Carlson, C. W.: Scaling of 3D solitary waves observed by FAST ...

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On the Earth’s Magnetic Field and the Hall Effect : Volume 10, Iss...

By: J. E. Allen

Description: University College, Oxford, OX1 4BH, UK. In a recent paper de Paor put forward a new theory of the Earth's magnetic field that depended on the Hall effect as an energy transfer mechanism. The purpose of this paper is to demonstrate that the mechanism invoked is unimportant except in certain gaseous plasmas.

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Facies Recognition Using Wavelet Based Fractal Analysis and Wavefo...

By: M. Aldana; M. López

Description: Earth Science Department, Simón Bolívar University, Caracas, Venezuela. We have used a Wavelet Based Fractal Analysis (WBFA) and a Waveform Classifier (WC) to recognize lithofacies at the Oritupano A field (Oritupano-Leona Block, Venezuela). The WBFA was applied first to Sonic, Density, Gamma Ray and Porosity well logs in the area. The logs that give the best response to the WBFA are the Gamma Ray and NPHI (porosity) logs. In the case of the logs, the l...

Akay, M.: Wavelets in biomedical engineering, Wavelet transforms in biomedical engineering, 23(5), 531–542, 1995.; Álvarez, G., Sansó, B., Michelena, R. J., and Jiménez, J. R.: Lithologic characterization of a reservoir using continuous-wavelet transforms, IEEE Trans. Geos. Rem. Sen., 41(1), 59–65, 2003.; Argoul, F., Arneodo, J., Elezgaray, J., Grasseau, G., and Murenzi, R.: Wavelet transform of fractal aggregates, Phys. Lett. A, 135, 6–7, 327–336, 1989.; AristimuÑo, J. ...

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Lagrangian Drifter Paths and Length Scales in the Tropical Pacific...

By: Z. Fang; T. Nakanishi; T. Kawano; Y. Kashino; S. Nakamoto; K. Muneyama

Description: Japan Marine Science and Technology Center, 2-15, Natsushima-cho, Yokosuka, 237, Japan. This paper presents an analysis of WOCE/TOGA surface drifter paths and its interpretation in conjunction with the west Pacific warm pool water motion. Our interest here lies in the existence of scale invariance in the observed data sets. The analysis proceeds by detecting scale invariance in the drifter paths data, and interpreting the invariance in terms of the stati...

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Using Mssa to Determine Explicitly the Oscillatory Dynamics of Wea...

By: P. Yiou; R. Kleeman; S. Speich; S. Raynaud

Description: Laboratoire des Sciences du Climat et de l’Environnement, CEA, Gif-sur-Yvette, France. This paper presents a statistical diagnostic to interpret the dynamics of nonlinear variability in models. It consists in applying the Multichannel Singular Spectrum Analysis to the variability of a suitable equation of a dynamical system. This method enables us to evaluate the sensitivity of the oscillatory features of a physical model to tendencies in its mathematic...

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Large Eddy Simulation Model for Wind-driven Sea Circulation in Coa...

By: F. Roman; C. Nasello; A. Petronio; V. Armenio

Description: Dipartimento di Ingegneria e Architettura, Università di Trieste, Piazzale Europa 1, 34127 Trieste, Italy. In the present paper a state-of-the-art large eddy simulation model (LES-COAST), suited for the analysis of water circulation and mixing in closed or semi-closed areas, is presented and applied to the study of the hydrodynamic characteristics of the Muggia bay, the industrial harbor of the city of Trieste, Italy. The model solves the non-hydrostatic...

Armenio, V. and Roman, F.: Large Eddy Simulation of environmental shallow water coastal flow, Ercoftac Bulletin, 78, 46–53, 2009.; Balaras, E.: Modeling complex boundaries using an external force field on fixed Cartesian grids in large-eddy simulations, Comput. Fluids, 33, 375–404, 2004.; Burchard, H., Craig, P., Gemmrich, J., Haren, H. V., Mathieu, P., Meier, H. M., Smith, W. N., Prandke, H., Rippeth, T., Skyllingstad, E., Smyth, W., Welsh, D., and Wijesekera, H.: Obser...

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Forced Versus Coupled Dynamics in Earth System Modelling and Predi...

By: H. Held; H. J. Schellnhuber; B. Knopf

Description: Potsdam Institute for Climate Impact Research (PIK), P.O. Box 601203,14412 Potsdam, Germany. We compare coupled nonlinear climate models and their simplified forced counterparts with respect to predictability and phase space topology. Various types of uncertainty plague climate change simulation, which is, in turn, a crucial element of Earth System modelling. Since the currently preferred strategy for simulating the climate system, or the Earth System at...

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Particle-in-cell Simulations of a Lens on an F-plane : Volume 4, I...

By: C. E. Grosch; J. J. Holdzkom II.; A. D. Kirwan, Jr.

Description: Center for Coastal Physical Oceanography, Old Dominion University, Norfolk, Virginia, 23529 USA. A particle-in-cell ansatz for solving the Euler equations in a rotating frame is described. The approach is ideally suited for layered models of flows with sharp density and velocity fronts. The material and Coriolis accelerations in the Euler equations are solved at each particle while the gradient accelerations are evaluated on a grid and interpolated at e...

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Heliospheric Pick-up Ions Influencing Thermodynamics and Dynamics ...

By: D. Rucinski; H. J. Fahr

Description: Institut für Astrophysik und Extraterrestrische Forschung der Universität Bonn, Auf dem Hügel 71, D-53121 Bonn, Germany. Neutral interstellar H-atoms penetrate into the inner heliosphere and upon the event of ionization are converted into pick-up ions (PUIs). The magnetized solar wind flow incorporates these ions into the plasma bulk and enforces their co-motion. By nonlinear interactions with wind-entrained Alfvén waves, these ions are t...

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Computation of Hyperbolic Trajectories and Their Stable and Unstab...

By: D. Small; S. Wiggins; A. M. Mancho

Description: School of Mathematics, University Walk, University of Bristol, Bristol BS8 1 TW, UK. In this paper, we describe a unified algorithm for locating and computing hyperbolic trajectories, and then computing their stable and unstable manifolds, for finite time velocity fields in the form of a data set defined on a space-time grid. The algorithm is applied to a turbulent regime of a quasigeostrophic wind-driven double gyre in a rectangular domain.

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

By: G. Wang; X. Chen

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 perturbations of the observed system. Therefore, these external driving forces should be taken into account when reconstructing the climate dynamics. This paper presents a new technique of combinin...

Berkes, P. and Wiskott, L.: Slow feature analysis yields a rich repertoire of complex cell properties, J. Vision, 5, 579–602, 2005.; Boucharel, J., Dewitte, B., Garel, B., and du Penhoat, Y.: ENSO's non-stationary and non-Gaussian character: the role of climate shifts, Nonlin. Processes Geophys., 16, 453–473, doi:10.5194/npg-16-453-2009, 2009.; Brasseur, G. and Granier, C.: Mount Pinatubo aerosols, chlorofluorocarbons...

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On Closure Parameter Estimation in Chaotic Systems : Volume 19, Is...

By: A. Solonen; M. Laine; J. Tamminen; A. Ilin; E. Oja; J. Hakkarainen; H. Haario; H. Järvinen

Description: Finnish Meteorological Institute, Helsinki, Finland. Many dynamical models, such as numerical weather prediction and climate models, contain so called closure parameters. These parameters usually appear in physical parameterizations of sub-grid scale processes, and they act as tuning handles of the models. Currently, the values of these parameters are specified mostly manually, but the increasing complexity of the models calls for more algorithmic ...

Annan, J. and Hargreaves, J.: Efficient estimation and ensemble generation in climate modelling, Phil. Trans. R. Soc. A, 365, 2077–2088, doi:10.1098/rsta.2007.2067, 2007.; Annan, J. D., Lunt, D. J., Hargreaves, J. C., and Valdes, P. J.: Parameter estimation in an atmospheric GCM using the Ensemble Kalman Filter, Nonlin. Processes Geophys., 12, 363–371, doi:10.5194/npg-1...

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