World Library  


 
  • Cover Image

Conditional Nonlinear Optimal Perturbations of the Double-gyre Oce...

By: H. A. Dijkstra; A. D. Terwisscha Van Scheltinga

Description: Institute for Marine and Atmospheric research Utrecht, Department of Physics and Astronomy, Utrecht University, Utrecht, The Netherlands. In this paper, we study the development of finite amplitude perturbations on linearly stable steady barotropic double-gyre flows in a rectangular basin using the concept of Conditional Nonlinear Optimal Perturbation (CNOP). The CNOPs depend on a time scale of evolution te and an initial perturbation th...

Crisciani, F. and Mosetti, R.: On the stability of wind-driven flows in oceanic basins, J. Phys. Oceanogr., 20, 1787–1790, 1990.; Crisciani, F., Cavallini, F., and Mosetti, R.: Stability of analytical solutions of Stommel-Veronis ocean circulation models, J. Phys.\ Oceanogr., 24, 155–158, 1994.; Crisciani, F., Cavallini, F., and Mosetti, R.: Nonlinear asymptotic stability of Munk's solution of the general circulation problem, J. Phys. Oceanogr., 25, 1723–1729, 1995.; Dij...

Read More
  • Cover Image

Characterizing the Nonlinear Internal Wave Climate in the Northeas...

By: Y. J. Yang; F. L. Bahr; S. R. Ramp

Description: Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA, 95039, USA. Four oceanographic moorings were deployed in the South China Sea from April 2005 to June 2006 along a transect extending from the Batanes Province, Philippines in the Luzon Strait to just north of Dong-Sha Island on the Chinese continental slope. The purpose of the array was to observe and track large-amplitude nonlinear internal waves (NIWs) from generation to s...

Liu, A. K., Ramp, S. R., Zhao, Y., and Tang, T.-Y.: A case study of internal solitary wave propagation during ASIAEX 2001, IEEE J. Oceanic Eng., 29, 1144–1156, 2004.; Akylas, T. R., Grimshaw, R. H. J., Clarke, S. R., and Tabaei, A.: Reflecting tidal wave beams and local generation of solitary waves in the ocean thermocline, J. Fluid Mech., 593, 297–313, 2007.; Alford, M. H., Lien, R.-C., Simmons, H., Klymak, J., Ramp, S. R., Yang, Y. J., Tang, T.-Y., Farmer, D., and Chan...

Read More
  • Cover Image

Representing Model Error in Ensemble Data Assimilation : Volume 21...

By: R. Buizza; N. Žagar; G. Radnoti; C. Cardinali

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...

Read More
  • Cover Image

Meteorological Uncertainty and Rainfall Downscaling : Volume 14, I...

By: N. Rebora; A. Provenzale; L. Ferraris; J. Von Hardenberg

Description: ISAC-CNR, Corso Fiume 4, 10133 Torino, Italy. We explore the sources of forecast uncertainty in a mixed dynamical-stochastic ensemble prediction chain for small-scale precipitation, suitable for hydrological applications. To this end, we apply the stochastic downscaling method RainFARM to each member of ensemble limited-area forecasts provided by the COSMO-LEPS system. Aim of the work is to quantitatively compare the relative weights of the meteorolog...

Adlerman, E J. and Droegemeier, K K.: The sensitivity of numerically simulated cyclic mesocyclogenesis to variations in model physical and computational parameters, Mon. Wea. Rev., 130, 2671–2691, 2002.; Bell, T L.: A space-time stochastic model of rainfall for satellite remote sensing studies, J. Geophys. Res., 92, 9631–9643, 1987.; Buizza, R. and Palmer, T N.: Impact of ensemble size on ensemble prediction, Mon. Wea. Rev., 126, 2503–2518, 1998.; Du, J., Mullen, S L., a...

Read More
  • Cover Image

Analysis of Asymmetries in Propagating Mode-2 Waves : Volume 20, I...

By: A. Baglaenko; M. Stastna; J. Olsthoorn

Description: University of Waterloo, Ontario, Canada. Using numerical simulations performed with a pseudo-spectral incompressible Navier–Stokes solver, we describe the asymmetries that arise in the recirculating core of mode-2 internal, solitary-like waves. The waves are generated in a manner consistent with many laboratory studies, namely via the collapse of a region of mixed fluid. Analysis of the simulations reveals that asymmetries across both the wave crest and ...

Akylas, T. R. and Grimshaw, R. H. J.: Solitary internal waves with oscillatory tails, J. Fluid Mech., 242, 279–298, 1992.; Boehrer, B. and Schultze, M.: Stratification of lakes, Rev. Geophys., 46, RG2005, doi:10.1029/2006RG000210, 2008.; Boyd, J.: Chebyshev and Fourier spectral methods: Second revised edition, Dover books on mathematics, Dover Publications, 2001.; Camassa, R., Rusås, P.-O., Saxena, A., and Tiron, R.: Ful...

Read More
  • Cover Image

A Potential Implicit Particle Method for High-dimensional Systems ...

By: R. N. Miller; Y. H. Spitz; B. Weir

Description: College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA. This paper presents a particle method designed for high-dimensional state estimation. Instead of weighing random forecasts by their distance to given observations, the method samples an ensemble of particles around an optimal solution based on the observations (i.e., it is implicit). It differs from other implicit methods because it includes the state at...

Bellman, R. E.: Dynamic programming, Princeton University Press, Princeton, 1957.; Ades, M. and van Leeuwen, P. J.: An exploration of the equivalent weights particle filter, Q. J. Roy. Meteor. Soc., 139, 820–840, 2013.; Alspach, D. L. and Sorenson, H. W.: Nonlinear Bayesian estimation using Gaussian sum approximations, IEEE T. Automat. Contr., AC-17, 439–448, 1972.; Anderson, J. L. and Anderson, S. L.: A Monte Carlo implementation of the nonlinear filtering problem to pr...

Read More
  • Cover Image

Soil Nutrient Cycles as a Nonlinear Dynamical System : Volume 11, ...

By: I. Rodriguez-iturbe; S. Manzoni; F. Laio; P. D'Odorico; A. Porporato

Description: Department of Civil and Environmental Engineering, Duke University, 127 Hudson Hall, Durham, NC 27708, USA. An analytical model for the soil carbon and nitrogen cycles is studied from the dynamical system point of view. Its main nonlinearities and feedbacks are analyzed by considering the steady state solution under deterministic hydro-climatic conditions. It is shown that, changing hydro-climatic conditions, the system undergoes dynamical bifurcations,...

Read More
  • Cover Image

An Update on Thorpex-related Research in Data Assimilation and Obs...

By: M. Tsyrulnikov; P. Gauthier; C. Cardinali; F. Rabier; R. Langland; P. Steinle; A. Lorenc; K. Koizumi; R. Gelaro

Description: CNRM/GAME, Météo-France and CNRS, France. The international programme THORPEX: a World Weather Research Programme provides a framework in which to tackle the challenge of improving the forecast skill of high-impact weather through international collaboration between academic institutions, operational forecast centres, and users of forecast products. The objectives of the THORPEX Data Assimilation and Observation Strategy Working Group (DAOS-WG) are two-f...

Atlas, R. A.: Atmospheric observations and experiments to assess their usefulness in data assimilation, J. Meteorol. Soc. Jpn., 75, 111–130, 1997.; Auligné, T., McNally, A. P., and Dee, D. P.: Adaptive bias correction for satellite data in a numerical weather prediction system, Q. J. Roy. Meteorol. Soc., 133, 631–642, 2007.; Baker, N. L. and Daley, R.: Observation and background adjoint sensitivity in the adaptive observation targeting problem, Q. J. Roy. Meteorol. Soc.,...

Read More
  • Cover Image

Enso's Non-stationary and Non-gaussian Character: the Role of Clim...

By: Y. Du Penhoat; B. Garel; B. Dewitte; J. Boucharel

Description: Université de Toulouse, UPS, LEGOS, 14 Av, Edouard Belin, 31400 Toulouse, France. El Niño Southern Oscillation (ENSO) is the dominant mode of climate variability in the Pacific, having socio-economic impacts on surrounding regions. ENSO exhibits significant modulation on decadal to inter-decadal time scales which is related to changes in its characteristics (onset, amplitude, frequency, propagation, and predictability). Some of these characteristics ten...

Chen, D., Cane, M. A., Kaplan, A., Zebiak, S. E., and Huang, D: Predictability of El Niño over the past 148 years, Nature, 428, 733–736, 2004.; An, S.-I.: Interdecadal changes in the El Nino-La Nina asymmetry, Geophys. Res. Lett., 31, L23210, doi:101029/2004GL021299, 2004.; An, S.-I. and Jin, F. F.: Nonlinearity and asymmetry of ENSO, J. Climate, 17, 2399–2412, 2004.; An, S.-I., Hsieh, W. W., and Jin F.-F.: A nonlinear analysis of ENSO cycle and its interdecadal changes,...

Read More
  • Cover Image

Image-model Coupling: Application to an Ionospheric Storm : Volume...

By: C. N. Mitchell; D. Pokhotelov; C. J. Budd; N. D. Smith

Description: Department of Mathematical Sciences, University of Bath, Bath, BA2 7AY, UK. Techniques such as tomographic reconstruction may be used to provide images of electron content in the ionosphere. Models are also available which attempt to describe the dominant physical processes operating in the ionosphere, or the statistical relationships between ionospheric variables. It is sensible to try and couple model output to tomographic images with the aim of infer...

Bhuyan, K. and Bhuyan, P.: International Reference Ionosphere as a potential regularization profile for computerized ionospheric tomography, Adv. Space Res., 39, 851–858, 2007.; Bilitza, D.: International Reference Ionosphere – Status 1995/96, Adv. Space Res., 20, 1751–1754, 1997.; Bust, G. and Mitchell, C.: History, current state, and future directions of ionospheric imaging, Rev. Geophys., 46, RG1003, doi:10.1029/2006RG000212, 2008.; Dow, J., Neilan, R., and Rizos, C.:...

Read More
  • Cover Image

Representation of Model Error in a Convective-scale Ensemble Predi...

By: R. N. Bannister; S. Migliorini; A. C. Rudd; L. H. Baker

Description: Department of Meteorology, University of Reading, Earley Gate, P.O. Box 243, Reading, RG6 6BB, UK. In this paper ensembles of forecasts (of up to six hours) are studied from a convection-permitting model with a representation of model error due to unresolved processes. The ensemble prediction system (EPS) used is an experimental convection-permitting version of the UK Met Office's 24-member Global and Regional Ensemble Prediction System (MOGREPS). The me...

Berner, J., Shutts, G. J., Leutbecher, M., and Palmer, T. N.: A spectral stochastic kinetic energy backscatter scheme and its impact on flow-dependent predictability in the ECMWF Ensemble Prediction System, J. Atmos. Sci., 66, 603–629, 2009.; Berner, J., Ha, S.-Y., Hacker, J. P., Fournier, A., and Snyder, C.: Model uncertainty in a mesoscale ensemble prediction system: Stochastic versus multiphysics representations, Mon. Weather Rev., 139, 1972–1995, 2011.; Bishop, C. H....

Read More
  • Cover Image

On the Interaction of Wind and Steep Gravity Wave Groups Using Mil...

By: C. Kharif; E. Pelinovsky; J.-p. Giovanangeli; J. Touboul

Description: Laboratoire de Sondages Electromagnétiques de l'Environnement Terrestre, Toulon, France. The interaction of wind and water wave groups is investigated theoretically and numerically. A steep wave train is generated by means of dispersive focusing, using both the linear theory and fully nonlinear equations. The linear theory is based on the Schrödinger equation while the nonlinear approach is developed numerically within the framework of the potential the...

Banner, M. I. and Song, J.-B.: On determining the onset and strength of breaking for deep water waves. part ii : Influence of wind forcing and surface shear, J. Phys. Oceanogr., 32(9), 2559–2570, 2002.; Belcher, S. E. and Hunt, J. C. R.: Turbulent flows over hill and waves, Annu. Rev. Fluid. Mech., 30, 507–538, 1998.; Benney, D. J. and Newell, A. C.: The propagation of nonlinear wave envelop, J. Math. Phys., 46, 133–139, 1967.; Brown, M. G. and Jensen, A.: Experiments on...

Read More
  • Cover Image

Self-similarity of Wind-driven Seas : Volume 12, Issue 6 (03/11/2005)

By: V. E. Zakharov; D. Resio; A. N. Pushkarev; S. I. Badulin

Description: University of Arizona, Tucson, USA. The results of theoretical and numerical study of the Hasselmann kinetic equation for deep water waves in presence of wind input and dissipation are presented. The guideline of the study: nonlinear transfer is the dominating mechanism of wind-wave evolution. In other words, the most important features of wind-driven sea could be understood in a framework of conservative Hasselmann equation while forcing and di...

Read More
  • Cover Image

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...

Read More
  • Cover Image

Conditioning Model Output Statistics of Regional Climate Model Pre...

By: Y. He; J. Freer; F. Pappenberger; F. Wetterhall; H. L. Cloke

Description: European Centre for Medium Range Weather Forecasts, Reading, UK. Dynamical downscaling of Global Climate Models (GCMs) through regional climate models (RCMs) potentially improves the usability of the output for hydrological impact studies. However, a further downscaling or interpolation of precipitation from RCMs is often needed to match the precipitation characteristics at the local scale. This study analysed three Model Output Statistics (MOS) techniq...

Bardossy, A. and Pegram, G.: Downscaling precipitation using regional climate models and circulation patterns toward hydrology, Water Resour. Res., 47, doi:10.1029/2010WR009689, 2011.; Bardossy, A. and Plate, E.: Space-time model for daily rainfall using atmospheric circulation patterns, Water Resour. Res., 28, 1247–1259, 1992.; Baur, F., Hess, P., and Nagel, H.: Kalender der Grosswetterlagen Europas 1881–1939, Bad Hombu...

Read More
  • Cover Image

Climate Spectrum Estimation in the Presence of Timescale Errors : ...

By: D. Fleitmann; E. W. Wolff; R. Röthlisberger; D. Scholz; M. Mudelsee; A. Mangini

Description: British Antarctic Survey, Cambridge, UK. We introduce an algorithm (called REDFITmc2) for spectrum estimation in the presence of timescale errors. It is based on the Lomb-Scargle periodogram for unevenly spaced time series, in combination with the Welch's Overlapped Segment Averaging procedure, bootstrap bias correction and persistence estimation. The timescale errors are modelled parametrically and included in the simulations for determining (1...

Robinson, P. M.: Estimation of a time series model from unequally spaced data, Stoch. Process. Appl., 6, 9–24, 1977.; Röthlisberger, R., Mudelsee, M., Bigler, M., de Angelis, M., Fischer, H., Hansson, M., Lambert, F., Masson-Delmotte, V., Sime, L., Udisti, R., and Wolff, E. W.: The Southern Hemisphere at glacial terminations: insights from the Dome C ice core, Clim. Past, 4, 345–356, 2008.; Scargle, J. D.: Studies in astronomical time series analysis. II. Statistical asp...

Read More
  • Cover Image

Modelling Lava Flows by Cellular Nonlinear Networks (Cnn): Prelimi...

By: L. Fortuna; A. Vicari; C. Del Negro

Description: Istituto Nazionale di Geofisica e Vulcanologia – Sezione di Catania, Italy. The forecasting of lava flow paths is a complex problem in which temperature, rheology and flux-rate all vary with space and time. The problem is more difficult to solve when lava runs down a real topography, considering that the relations between characteristic parameters of flow are typically nonlinear. An alternative approach to this problem that does not use standard differe...

Read More
  • Cover Image

A Basing of the Diffusion Approximation Derivation for the Four-wa...

By: V. G. Polnikov

Description: The State Oceanographic Institute, Kropotkinskii Lane 6, Moscow, 119992 Russia. A basing of the diffusion approximation derivation for the Hasselmann kinetic integral describing nonlinear interactions of gravity waves in deep water is discussed. It is shown that the diffusion approximation containing the second derivatives of a wave spectrum in a frequency and angle (or in wave vector components) is resulting from a step-by-step analytica...

Read More
  • Cover Image

On the Predictability of Ice Avalanches : Volume 12, Issue 6 (30/0...

By: C. Birrer; W. A. Stahel; M. Funk; A. Pralong

Description: Laboratory of Hydraulics, Hydrology and Glaciology, Swiss Federal Institute of Technology, 8092 Zürich, Switzerland. The velocity of unstable large ice masses from hanging glaciers increases as a power-law function of time prior to failure. This characteristic acceleration presents a finite-time singularity at the theoretical time of failure and can be used to forecast the time of glacier collapse. However, the non-linearity of the power-law function mak...

Read More
  • Cover Image

Fractal Time Statistics of Ae-index Burst Waiting Times: Evidence ...

By: P. De Michelis; G. Consolini

Description: Istituto di Fisica dello Spazio Interplanetario – CNR, Roma, Italy. Recent observations and analyses evidenced that the magnetotail, as well as the magnetospheric dynamics are characterised by a scale-free behaviour and intermittence. These results, along with numerical simulations on cellular automata, suggest that the observed scale-invariance may be due to forced and/or self-organised criticality (FSOC), meaning that the magneto...

Read More
 
1
|
2
|
3
Records: 1 - 20 of 45 - Pages: 



Copyright © World Library Foundation. All rights reserved. eBooks from Hawaii eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.