Now showing items 39-58 of 333

  • Caution needed when linking weather extremes to amplified planetary waves 

    Screen, James A.; Simmonds, Ian (National Academy of Sciences, 2013)
  • The central role of diminishing sea ice in recent Arctic temperature amplification 

    Screen, James A.; Simmonds, Ian (Nature Publishing Group, 2010)
    The rise in Arctic near-surface air temperatures has been almost twice as large as the global average in recent decades-a feature known as 'Arctic amplification'. Increased concentrations of atmospheric greenhouse gases ...
  • Chaos in symmetric phase oscillator networks 

    Bick, Christian; Timme, Marc; Paulikat, Danilo; Rathlev, Dirk; Ashwin, Peter (American Physical Society, 2011)
    Phase-coupled oscillators serve as paradigmatic models of networks of weakly interacting oscillatory units in physics and biology. The order parameter which quantifies synchronization so far has been found to be chaotic ...
  • Characteristic matrices for linear periodic delay differential equations 

    Sieber, J.; Szalai, R. (2011)
    Szalai, Stépán, and Hogan [SIAM J. Sci. Comput., 28 (2006), pp. 1301–1317] gave a general construction for characteristic matrices for systems of linear delay differential equations with periodic coefficients. First, we ...
  • Classification of robust heteroclinic cycles for vector fields in R3 with symmetry 

    Hawker, David; Ashwin, Peter (Institute of Physics, 2005)
    We consider a classification of robust heteroclinic cycles in the positive octant of R3 under the action of the symmetry group (Z2)3. We introduce a coding system to represent different classes up to a topological equivalence, ...
  • Classification of wave regimes in excitable systems with linear cross diffusion 

    Tsyganov, M. A.; Biktashev, V. N. (American Physical Society, 2014)
    We consider principal properties of various wave regimes in two selected excitable systems with linear cross diffusion in one spatial dimension observed at different parameter values. This includes fixed-shape propagating ...
  • Climate impacts of geoengineering marine stratocumulus clouds 

    Jones, Andy; Haywood, James M.; Boucher, Olivier (American Geophysical Union (AGU), 2009)
    [1] Theoretical potential geoengineering solutions to the global warming problem have recently been proposed. Here, we present an idealized study of the climate response to deliberately seeding large-scale stratocumulus ...
  • Climate impacts of the southern annular mode simulated by the CMIP3 models 

    Karpechko, Alexey Yu; Gillett, Nathan P.; Marshall, Gareth J.; Screen, James A. (American Meteorological Society, 2009)
    The southern annular mode (SAM) has a well-established impact on climate in the Southern Hemisphere. The strongest response in surface air temperature (SAT) is observed in the Antarctic, but the SAM’s area of influence ...
  • Climate predictions: the influence of nonlinearity and randomness 

    Thompson, J.M.; Sieber, J. (Royal Society, 2012)
    The current threat of global warming and the public demand for confident projections of climate change pose the ultimate challenge to science: predicting the future behaviour of a system of such overwhelming complexity as ...
  • Climate tipping as a noisy bifurcation: a predictive technique 

    Thompson, J.M.; Sieber, J. (Oxford University Press for Institute of Mathematics and its Applications, 2011)
    It is often known, from modelling studies, that a certain mode of climate tipping (of the oceanic thermohaline circulation, for example) is governed by an underlying fold bifurcation. For such a case, we present a scheme ...
  • Climate–carbon cycle feedback analysis: results from the C4MIP model intercomparison 

    Friedlingstein, P.; Cox, Peter M.; Betts, R. A.; Bopp, L.; Von Bloh, W.; Brovkin, V.; Cadule, P.; Doney, S.; Eby, M.; Fung, I.; Bala, G.; John, J.; Jones, Chris D.; Joos, F.; Kato, T.; Kawamiya, M.; Knorr, W.; Lindsay, K.; Matthews, H. D.; Raddatz, T.; Rayner, P.; Reick, C.; Roeckner, E.; Schnitzler, K.-G.; Schnur, R.; Strassmann, K.; Weaver, A. J.; Yoshikawa, C.; Zeng, N. (American Meteorological Society, 2006)
    Eleven coupled climate-carbon cycle models used a common protocol to study the coupling between climate change and the carbon cycle. The models were forced by historical emissions and the Intergovernmental Panel on Climate ...
  • Cluster observations of the mid-altitude cusp under strong northward Interplanetary magnetic field 

    Hu, Renyu; Bogdanova, Yulia V.; Owen, Christopher J.; Foullon, Claire; Fazakerley, Andrew; Reme, Henri (American Geophysical Union (AGU), 2008)
    We report on a multispacecraft cusp observation lasting more than 100 min. We determine the cusp boundary motion and reveal the effect on the cusp size of the interplanetary magnetic field (IMF) changing from southward to ...
  • Comparing the degree of land–atmosphere interaction in four atmospheric general circulation models 

    Koster, Randal D.; Dirmeyer, Paul A.; Hahmann, Andrea N.; Ijpelaar, Ruben; Tyahla, Lori; Cox, Peter M.; Suarez, Max J. (American Meteorological Society, 2002)
    The strength of the coupling between the land and the atmosphere, which controls, for example, the degree to which precipitation-induced soil moisture anomalies affect the overlying atmosphere and thereby the subsequent ...
  • Comparison of the Bayesian and Randomised Decision Tree Ensembles within an Uncertainty Envelope Technique 

    Schetinin, Vitaly; Fieldsend, Jonathan E.; Partridge, Derek; Krzanowski, Wojtek J.; Everson, Richard M.; Bailey, Trevor C.; Hernandez, Adolfo (Springer, 2006)
    Multiple Classifier Systems (MCSs) allow evaluation of the uncertainty of classification outcomes that is of crucial importance for safety critical applications. The uncertainty of classification is determined by a trade-off ...
  • Computation of the drift velocity of spiral waves using response functions 

    Biktasheva, I. V.; Barkley, D.; Biktashev, V. N.; Foulkes, A. J. (American Physical Society, 2010)
    Rotating spiral waves are a form of self-organization observed in spatially extended systems of physical, chemical, and biological nature. In the presence of a small perturbation, the spiral wave's center of rotation and ...
  • Computation of the response functions of spiral waves in active media 

    Biktasheva, I. V.; Barkley, D.; Biktashev, V. N.; Bordyugov, G. V.; Foulkes, A. J. (American Physical Society, 2009)
    Rotating spiral waves are a form of self-organization observed in spatially extended systems of physical, chemical, and biological natures. A small perturbation causes gradual change in spatial location of spiral's rotation ...
  • A Computer Simulation Study of Anatomy Induced Drift of Spiral Waves in the Human Atrium 

    Kharche, Sanjay R.; Biktasheva, I. V.; Seemann, Gunnar; Zhang, Henggui; Biktashev, V. N. (Hindawi Publishing Corporation, 2014)
    The interaction of spiral waves of excitation with atrial anatomy remains unclear. This simulation study isolates the role of atrial anatomical structures on spiral wave spontaneous drift in the human atrium. We implemented ...
  • Conditions for propagation and block of excitation in an asymptotic model of atrial tissue. 

    Simitev, R. D.; Biktashev, V. N. (2006)
    Detailed ionic models of cardiac cells are difficult for numerical simulations because they consist of a large number of equations and contain small parameters. The presence of small parameters, however, may be used for ...
  • Conditions for sink-to-source transitions and runaway feedbacks from the land carbon cycle 

    Cox, Peter M.; Huntingford, Chris; Jones, Chris D. (Cambridge University Press, 2006-02)
    The first GCM climate-carbon cycle simulation indicated that the land biosphere could provide a significant acceleration of 21st century climate change (Cox et al. 2000). In this numerical experiment the carbon storage was ...
  • Cone exchange transformations and boundedness of orbits 

    Ashwin, Peter; Goetz, Arek (Cambridge University Press, 2010)
    We introduce a class of two-dimensional piecewise isometries on the plane that we refer to as cone exchange transformations (CETs). These are generalizations of interval exchange transformations (IETs) to 2D unbounded ...