Description: Space and Atmospheric Physics group, Blackett Laboratory, Imperial College, London, UK. As the dissipation mechanisms considered for the heating of the solar corona would be sufficiently efficient only in the presence of small scales, turbulence is thought to be a key player in the coronal heating processes: it allows indeed to transfer energy from the large scales to these small scales. While Direct numerical simulations which have been performed ...
Abramenko, V I., Yurchyshyn, V B., Wang, H., Spirock, T J., and Goode, P R.: Scaling Behavior of Structure Functions of the Longitudinal Magnetic Field in Active Regions on the Sun, Astrophys. J., 577, 487–495, 2002.; Alexakis, A., Mininni, P D., and Pouquet, A.: Shell-to-shell energy transfer in magnetohydrodynamics. I. Steady state turbulence, Phys. Rev. E, 72, 046 301, 2005.; Bak, P., Tang, C., and Wiesenfeld, K.: Self-organized criticality – An explanation of $1/f$ n...
Description: National Geophysical Research Institute (Council of Scientific & Industrial Research), Uppal Road, Hyderabad-500007, India. Terrestrial heat flow is considered an important parameter in studying the regional geotectonic and geodynamic evolutionary history of any region. However, its distribution is still very uneven. There is hardly any information available for many geodynamically important areas. In the present study, we provide a methodology to predic...
Artemieva, I. M. and Mooney, W. D.: Thermal thickness and evolution of Precambrian lithosphere: a global study, J. Geophys. Res., 106, B8, 16387–�16414, 2001.; Balaram, V. and Rao, T. G.: Rapid determination of REEs and other trace elements in geological samples by microwave acid digestion and ICP-MS, Atom. Spectrosc., 24, 206–212, 2003.; Ballard, S., Pollack, H. N., and Skinner, N. J.: Terrestrial heat flow in Botswana and Namibia, J. Geophys. Res., 92, 6291–6300, 1987....
Description: Center for Remote Sensing, Graduate College of Marine Studies, University of Delaware, Newark, DE 19716, USA. TOPEX/POSEIDON (T/P) sea level deviation (SLD) time series from 3 October 1992 to 15 May 1997 combined with upper ocean thermal structures are used to observe the characteristics and analyze the dynamics of equatorial waves in the Pacific Ocean. The evolution of the Kelvin wave propagating along an eastward shoaling thermocline in the equatorial ...
Description: Department of Electrical and Computer Engineering, Demokritos Univercity of Thrace, 67100 Xanthi, Greece. The singular value decomposition (SVD) analysis is used at different stages in this paper in order to extract useful information concerning the underlying dynamics of the magnetospheric AE index. As a frame of reference we use the dynamics of the Lorenz system perturbed by external noise, white or colored. One of the critical results ...
Description: Department of Mathematics and Statistics, University of Maryland-Baltimore County, Baltimore, Maryland, USA. A one dimensional non-linear magneto-hydrodynamic (MHD) system has been introduced to test a sequential optimal interpolation assimilation technique that uses a Monte-Carlo method to calculate the forecast error covariance. An ensemble of 100 model runs with perturbed initial conditions are used to construct the covariance, and the assimilation alg...
Bloxham, J., Gubbins, D., and Jackson, A.: Geomagnetic secular variation, Phil. Trans. Roy. Soc. Lond. A, 329, 415–502, 1989.; Borovikov, A., Rienecker, M. M., Keppene, C. L., and Johnson, C. C.: Multivariate error covariance estimates by Monte-Carlo simulation for assimilation studies in the Pacific Ocean, Monthly Weather Review, 133, 2310–2334, 2005.; Braginsky, S. I.: Magnetic waves in the Earth's core, Geomag. Aeron., 7, 851–859, 1967.; Braginsky, S. I.: Torsional ma...
Description: Institute of Geophysics and Extraterrestrial Physics, Technical University of Braunschweig, Mendelssohnstr. 3, 38106 Braunschweig, Germany. Waves in the foreshock region are studied on the basis of a hypothesis that the linear process first excites the waves and further wave-wave nonlinearities distribute scatter the energy of the primary waves into a number of daughter waves. To examine this wave evolution scenario, the dispersion relations, the wav...
Spangler, S. R., Leckband, J. A., and Cairns, I. H.: Observations of the parametric decay instability of nonlinear magnetohydrodynamic waves, Phys. Plasmas, 4, 846–855, 1997.; Terasawa, T., Hoshino, M., Sakai, J.-I., and Hada, T.: Decay instability of finite-amplitude circularly polarized Alfvén waves: A numerical simulation of stimulated brillouin scattering, J. Geophys. Res., 91, 4171–4187, 1986.; Araneda, J.: Parametric instabilities of parallel propagating Alfvén wav...
Description: Dept. of Mathematics and Statistics, Old Dominion University, Norfolk, Virginia, USA. A two dimensional system of autonomous nonlinear ordinary differential equations models glacier growth and temperature changes on an idealized planet. We apply standard perturbative techniques from dynamical systems theory to study small amplitude periodic orbits about a constant equilibrium. The equations are put in cononical form and the local phase space topology is ...
Description: Key Laboratory of Ocean Circulation and Wave, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China. The approach of conditional nonlinear optimal perturbation (CNOP) was previously proposed to find the optimal initial perturbation (CNOP-I) in a given constraint. In this paper, we extend the CNOP approach to search for the optimal combined mode of initial perturbations and model parameter perturbations. This optimal combined mode, ...
Aanonsen, S. I.: Efficient history matching using a multiscale technique, SPE Reservoir Evaluation and Engineering, 154–164, February 2008.; Birgin, E. G., Martinez, J. M., and Raydan, M.: Nonmonotone spectral projected gradient methods on convex sets, SIAM J. Optimiz., 10, 1196–1211, 2000.; Chu, P. C., Lu, S. H., and Chen, Y. C.: Two kinds of predictability problems in Lorenz system and climate models, Second Hayes Symposium on Seasonal to Interannual Climate Variabilit...
Description: Centre de Recerca Matemàtica, Edifici Cc, Campus Bellaterra, 08193 Bellaterra, Barcelona, Spain. We analyze distributions of rain-event sizes, rain-event durations, and dry-spell durations for data obtained from a network of 20 rain gauges scattered in a region of the northwestern Mediterranean coast. While power-law distributions model the dry-spell durations with a common exponent 1.50 ± 0.05, density analysis is inconclusive for event sizes and event ...
ACA (Agència Catalana de l'Aigua/Catalan Water Agency), available at: http://aca-web.gencat.cat/aca (last access: April 2014), 2014.; Andrade, R. F. S., Schellnhuber, H. J., and Claussen, M.: Analysis of rainfall records: possible relation to self-organized criticality, Physica A, 254, 557–568, 1998.; Bak, P.: How Nature Works: The Science of Self-Organized Criticality, Copernicus, New York, 1996.; Bauke, H.: Parameter estimation...
Description: Space Sciences Laboratory, University of California, Berkeley, USA. A model is presented for a new type of fast solitary waves which is observed in downward current regions of the auroral zone. The three-dimensional, coherent structures are electrostatic, have a positive potential, and move along the magnetic field lines with speeds on the order of the electron drift. Their parallel potential profile is flattened and cannot fit to the ...
Description: The State Key Laboratory of Numerical Mo deling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China. Human activities and climate change are important factors that affect grassland ecosystems. A new optimization approach, the approach of conditional nonlinear optimal perturbation (CNOP) related to initial and parameter perturbations, is employed to explore th...
Barclay, A., Gill, P. E., and Rosen, J. B.: SQP methods and their application to numerical optimal control, Variational Calculus, Optimal Control and Applications, edited by: Schmidt, W. H., Heier, K., Bittner, L., and Bulirsch, R.: Birkhäuser Verlag, Basel, 207–222, 1998.; Chen, H., Tian, H., Liu, M., Melillo, J., Pan, S., and Zhang, C.: Effect of land-cover change on terrestrial carbon dynamics in the southern USA, J. Environ. Qual., 35, 1533–1547, 2006.; Fay, P. A., K...
Description: Ben-Gurion University, Beer-Sheva, Israel. We study the collisionless dynamics of electrons in the shock ramp using the numerical trajectory analysis in the model electric and magnetic fields of the shock. Even with very modest assumptions about the cross-shock potential the electron trajectories are very sensitive to the width of the ramp. The character of electron motion changes from the fully adiabatic (with conservation of v2 ...
Description: Applied Mathematics, University of Twente, The Netherlands. This paper concerns the description and the predictability of a freak event when at a certain position information in the form of a time signal is given. The prediction will use the phase information for an estimate of the position and time of the occurrence of a large wave, and to predict the measure of phase coherence at the estimated focussing position. The coherence and the spectrum will de...
Adcock, T. A. A. and Taylor, P. H.: The directional spreading of the Draupner wave and sea-state, in: Proc. 11th Int. Workshop on Wave Hindcasting and Forecasting, Halifax, Canada, 2009c.; Akhmediev, N., Ankiewicz, A., Soto-Crespo, J., and Dudley, J. M.: Rogue wave early warning through spectral measurements?, Phys. Lett. A, 375, 541–544, 2011.; Chen, X.: The set-down in the second-order Stokes' waves, in: International Conference on Hydrodynamics, Italy, 179–85, 2006.; ...
Description: Department of Mathematics and Statistics, Monash University, Clayton, 3168, Victoria, Australia. The propagation of large- amplitude internal waves in the ocean is studied here for the case when the nonlinear effects are of cubic order, leading to the modified Korteweg - de Vries equation. The coefficients of this equation are calculated analytically for several models of the density stratification. It is shown that the coefficient of the cubic nonlinear...
Description: Potsdam Institute for Climate Impact Research, P.O. Box 60 12 03, 14412 Potsdam, Germany. The assessment of trends in climatology and hydrology still is a matter of debate. Capturing typical properties of time series, like trends, is highly relevant for the discussion of potential impacts of global warming or flood occurrences. It provides indicators for the separation of anthropogenic signals and natural forcing factors by distinguishing between...
Description: Space Research Institute, Austrian Academy of Sciences, Graz, Austria. In order to estimate the dissipation time-scale in magnetic turbulence in the plasma sheet a novel method is introduced for classification of velocity dependent patterns of two-point probability density functions' shapes near their maxima. For the first time, we provide evidence for Reynolds number (velocity) dependent widening of the inertial range in the plasma sheet. Since spectra...
Description: Institute of Physics, P.O. Box 57, Yu-11001 Belgrade, Yugoslavia. A catalogue of nonlinear vortex structures associated with acoustic-gravity perturbations in the Earth's atmosphere is presented. Besides the previously known Kelvin-Stewart cat's eyes, dipolar and tripolar structures, new solutions having the form of a row of counter-rotating vortices, and several weakly two-dimensional vortex chains are given. The existence conditions...
Description: Department of Plasma Physics, Umeå University, S-90187 Umeå, Sweden. A general coupling coefficient for three wave interactions in an ideal MHD plasma is presented. Using a special stratified background atmosphere, an explicit symmetric form of the coupling coefficient is derived.
Description: Department of Physics of Complex Systems, Eötvös University, Budapest, Hungary. We present a near global statistics on the correlation properties of daily temperature records. Data from terrestrial meteorological stations in the Global Daily Climatology Network are analyzed by means of detrended fluctuation analysis. Long-range temporal correlations extending up to several years are detected for each station. In order to reveal nonlinearity, we evaluate...
Fraedrich, K., Luksch, U., and Blender, R. A.: 1/f-model for long time memory of the ocean surface temperature, Phys. Rev. E, 70, 037301, doi:10.1103/PhysRevE.70.037301, 2003.; Hegger, R., Kantz, H., and Schreiber, T.: Practical implementation of nonlinear time series methods: The TISEAN package, Chaos, 9, 413–435, 1999, The software package is publicly available at http://www.mpipks-dresden.mpg.de/ tisean.; Jun, W. C., Oh, G., and Kim, S.: Understanding volatility corre...
Description: European Centre for Medium-Range Weather Forecasts, Reading, UK. The paper investigates a method to represent model error in the ensemble data assimilation (EDA) system. The ECMWF operational EDA simulates the effect of both observations and model uncertainties. Observation errors are represented by perturbations with statistics characterized by the observation error covariance matrix whilst the model uncertainties are represented by stochastic perturba...
Desroziers, G. and Ivanov, S.: Diagnosis and adaptive tuning of observation-error parameters in a variational assimilation, Q. J. Roy. Meteor. Soc., 127, 1443–1452, 2001.; Desroziers, G., Berre, L., Chapnik, B., and Poli, P.: Diagnosis of observation, background and analysis error statistics in observation space, Q. J. Roy. Meteor. Soc., 131, 3385–3396, 2005.; Fisher, M.: Background error covariance modeling, in: Proceedings of the ECMWF Seminar on recent developments in...