Browsing Mathematics by Title
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Validating weather and climate models at small Rossby numbers: including a boundary layer
(Wiley / Royal Meteorological Society, 20160607)Ideally, the validation of weather and climate models requires that the predictions remain close to an exact solution of the governing equations. The complexity of weather and climate models means that it is not possible ... 
A Valuation Criterion for Normal Basis Generators of HopfGalois Extensions in Characteristic p
(Société Arithmétique de Bordeaux, 2011)Let S/R be a finite extension of discrete valuation rings of characteristic p>0, and suppose that the corresponding extension L/K of fields of fractions is separable and is HGalois for some KHopf algebra H. Let DS/R be ... 
The value of highresolution Met Office regional climate models in the simulation of multihourly precipitation extremes
(American Meteorological Society, 201408)Extreme value theory is used as a diagnostic for two highresolution (12km parameterized convection and 1.5km explicit convection) Met Office regional climate model (RCM) simulations. On subdaily time scales, the 12km ... 
Variance estimation for Brier Score decomposition
(Wiley / Royal Meteorological Society, 20130814)The Brier Score is a widelyused criterion to assess the quality of probabilistic predictions of binary events. The expectation value of the Brier Score can be decomposed into the sum of three components called reliability, ... 
Variation of fundamental groups of curves in positive characteristics
(American Mathematical Society, 20151023)In this paper we prove that given a nonisotrivial family of hyperbolic curves in positive characteristic, the isomorphism type of the geometric fundamental group is not constant on the fibres of the family. 
A verification framework for interannualtodecadal predictions experiments
(Springer Verlag, 20120824)Decadal predictions have a high profile in the climate science community and beyond, yet very little is known about their skill. Nor is there any agreed protocol for estimating their skill. This paper proposes a sound and ... 
Vertical discretizations giving optimal representation of normal modes: General equations of state
(Royal Meteorological Society, 2016)Previous work has identified a number of vertical discretizations of the nonhydrostatic compressible Euler equations that optimally capture the propagation of acoustic, inertiogravity, and Rossby waves. Here, that previous ... 
Viral and epidemiological determinants of the invasion dynamics of novel dengue genotypes
(Public Library of Science, 20101123)BACKGROUND: Dengue has become a major concern for international public health. Frequent epidemic outbreaks are believed to be driven by a complex interplay of immunological interactions between its four cocirculating ... 
Vortex Erosion in a Shallow Water Model of the Polar Vortex
(Elsevier, 20170413)The erosion of a model stratospheric polar vortex in response to bottom boundary forcing is investigated numerically. Stripping of filaments of air from the polar vortex has been implicated in the occurrence of stratospheric ... 
Vortex motion in a weak background shear flow
(Cambridge University Press, 2004)A point vortex is introduced into a weak background vorticity gradient at finite Reynolds number. As the vortex spreads viscously so the background vorticity becomes wrapped around it, leading to enhanced diffusion of ... 
Was the Little Ice Age more or less El Niñolike than the Medieval Climate Anomaly? Evidence from hydrological and temperature proxy data
(European Geosciences Union (EGU) / Copernicus Publications, 20170329)The El Niño–Southern Oscillation (ENSO) is the most important source of global climate variability on interannual timescales and has substantial environmental and socioeconomic consequences. However, it is unclear how it ... 
Wave dispersion properties of compound finite elements
(Elsevier for Academic Press, 20170228)Mixed finite elements use different approximation spaces for different dependent variables. Certain classes of mixed finite elements, called compatible finite elements, have been shown to exhibit a number of desirable ... 
Wavelet transformbased denoising for twophoton imaging of synaptic Ca2+ transients.
(Biophysical Society, 20130305)Postsynaptic Ca(2+) transients triggered by neurotransmission at excitatory synapses are a key signaling step for the induction of synaptic plasticity and are typically recorded in tissue slices using twophoton fluorescence ... 
Weak chimeras in minimal networks of coupled phase oscillators
(American Institute of Physics (AIP), 2015)We suggest a definition for a type of chimera state that appears in networks of indistinguishable phase oscillators. Defining a "weak chimera" as a type of invariant set showing partial frequency synchronization, we show ... 
Weak convergence to extremal processes and record events for nonuniformly hyperbolic dynamical systems
(Cambridge University Press (CUP), 20170907)For a measurepreserving dynamical system (X , f, µ), we consider the time series of maxima Mn = max{X1, . . . , Xn} associated to the process Xn = φ( f n−1 (x)) generated by the dynamical system for some observable φ ... 
Weakened tropical circulation and reduced precipitation in response to geoengineering
(Institute of Physics, 2014)Geoengineering by injection of reflective aerosols into the stratosphere has been proposed as a way to counteract the warming effect of greenhouse gases by reducing the intensity of solar radiation reaching the surface. ... 
A weibull approach for improving climate model projections of tropical cyclone windspeed distributions
(American Meteorological Society, 20140101)Reliable estimates of future changes in extreme weather phenomena, such as tropical cyclone maximum wind speeds, are critical for climate change impact assessments and the development of appropriate adaptation strategies. ... 
What is the spatial distribution of magnetic helicity injected in a solar active region?
(EDP Sciences, 2006)Context. Magnetic helicity is suspected to play a key role in solar phenomena such as flares and coronal mass ejections. Several investigations have recently computed the photospheric flux of magnetic helicity in active ... 
White paper: Uncertainty and variability in computational and mathematical models of cardiac physiology.
(Wiley, 20160315)The Cardiac Physiome effort is one of the most mature and successful applications of mathematical and computational models for describing and advancing the understanding of physiology. After five decades of development, ... 
Why RLC realizations of certain impedances need many more energy storage elements than expected
(Institute of Electrical and Electronics Engineers (IEEE), 20170209)It is a significant and longstanding puzzle that the resistor, inductor, capacitor (RLC) networks obtained by the established RLC realization procedures appear highly nonminimal from the perspective of linear systems ...