Browsing by Name "University of St Andrews. Applied Mathematics"
Now showing items 120 of 225

3D MHD modeling of twisted coronal loops
(20161010)  Journal articleWe perform MHD modeling of a single bright coronal loop to include the interaction with a nonuniform magnetic field. The field is stressed by random footpoint rotation in the central region and its energy is dissipated ... 
3D PiC code investigations of Auroral Kilometric Radiation mechanisms
(IOP PUBLISHING LTD, 2014)  Conference itemEfficient (similar to 1%) electron cyclotron radio emissions are known to originate in the X mode from regions of locally depleted plasma in the Earths polar magnetosphere. These emissions are commonly referred to as the ... 
3D wholeprominence fine structure modeling
(20150420)  Journal articleWe present the first 3D wholeprominence fine structure model. The model combines a 3D magnetic field configuration of an entire prominence obtained from nonlinear forcefree field simulations, with a detailed description ... 
3D wholeprominence fine structure modeling. II. Prominence evolution
(20151020)  Journal articleWe use the new threedimensional (3D) wholeprominence fine structure model to study the evolution of prominences and their fine structures in response to changes in the underlying photospheric magnetic flux distribution. ... 
Alfven wave phasemixing and damping in the ion cyclotron range of frequencies
(201101)  Journal articleAims. We determine the effect of the Hall term in the generalised Ohm's law on the damping and phase mixing of Alfven waves in the ion cyclotron range of frequencies in uniform and nonuniform equilibrium plasmas. Methods. ... 
Alfvén wave boundary condition for responsive magnetosphere ionosphere coupling
(20140501)  Journal articleThe solution of electric fields and currents in a heightresolved ionosphere is traditionally solved as an elliptic equation with Dirichlet or Neumann boundary condition in which the magnetosphere is represented as an ... 
Apparent crossfield superslow propagation of magnetohydrodynamic waves in solar plasmas
(20151015)  Journal articleIn this paper we show that the phase mixing of continuum Alfvén waves and/or continuum slow waves in magnetic structures of the solar atmosphere as, e.g., coronal arcades, can create the illusion of wave propagation across ... 
The appearance, motion, and disappearance of threedimensional magnetic null points
(20151030)  Journal articleWhile theoretical models and simulations of magnetic reconnection often assume symmetry such that the magnetic null point when present is colocated with a flow stagnation point, the introduction of asymmetry typically ... 
Are tornadolike magnetic structures able to support solar prominence plasma?
(20150720)  Journal articleRecent highresolution and highcadence observations have surprisingly suggested that prominence barbs exhibit apparent rotating motions suggestive of a tornadolike structure. Additional evidence has been provided by ... 
Automatic presentations and semigroup constructions
(201008)  Journal articleAn automatic presentation for a relational structure is, informally, an abstract representation of the elements of that structure by means of a regular language such that the relations can all be recognized by finite ... 
Backward wave cyclotronmaser emission in the auroral magnetosphere
(20141007)  Journal articleIn this Letter, we present theory and particleincell simulations describing cyclotron radio emission from Earth's auroral region and similar phenomena in other astrophysical environments. In particular, we find that the ... 
A balanced approach to modelling rotating stably stratified geophysical flows
(20030810)  Journal articleWe describe a new approach to modelling threedimensional rotating stratified flows under the Boussinesq approximation. This approach is based on the explicit conservation of potential vorticity, and exploits the underlying ... 
A Bayesian approach to fitting Gibbs processes with temporal random effects
(201212)  Journal articleWe consider spatial point pattern data that have been observed repeatedly over a period of time in an inhomogeneous environment. Each spatial point pattern can be regarded as a “snapshot” of the underlying point process ... 
Behind and beyond a theorem on groups related to trivalent graphs
(200812)  Journal articleIn 2006 we completed the proof of a fivepart conjecture that was made in 1977 about a family of groups related to trivalent graphs. This family covers all 2generator, 2relator groups where one relator specifies that a ... 
Bending and twisting instabilities of columnar elliptical vortices in a rotating strongly stratified fluid
(20060825)  Journal articleIn this paper, we investigate the threedimensional stability of the MooreSaffman elliptical vortex in a rotating stratified fluid. By means of an asymptotic analysis for long vertical wavelength perturbations and small ... 
Boundary layer flow beneath an internal solitary wave of elevation
(201002)  Journal articleThe waveinduced flow over a fixed bottom boundary beneath an internal solitary wave of elevation propagating in an unsheared, twolayer, stably stratified fluid is investigated experimentally. Measurements of the velocity ... 
CALIFA, the Calar Alto Legacy Integral Field Area survey : III. Second public data release
(201504)  Journal articleThis paper describes the Second Public Data Release (DR2) of the Calar Alto Legacy Integral Field Area (CALIFA) survey. The data for 200 objects are made public, including the 100 galaxies of the First Public Data Release ... 
Cancellative and Malcev presentations for finite Rees index subsemigroups and extensions
(200802)  Journal articleIt is known that, for semigroups, the property of admitting a finite presentation is preserved on passing to subsemigroups and extensions of finite Rees index. The present paper shows that the same holds true for Malcev, ... 
Clusters of small eruptive flares produced by magnetic reconnection in the Sun
(20140610)  Journal articleWe report on the formation of small solar flares produced by patchy magnetic reconnection between interacting magnetic loops. A threedimensional (3D) magnetohydrodynamic (MHD) numerical experiment was performed, where a ... 
Collisionless distribution function for the relativistic forcefree Harris sheet
(201201)  Journal articleA selfconsistent collisionless distribution function for the relativistic analogue of the forcefree Harris sheet is presented. This distribution function is the relativistic generalization of the distribution function ...