caa a22 4500 445816082 CHVBK 20180317145228.0 cr unu---uuuuu 170323e20110701xx s 000 0 eng 10.1007/s11214-010-9654-y doi (NATIONALLICENCE)springer-10.1007/s11214-010-9654-y Review Article: MHD Wave Propagation Near Coronal Null Points of Magnetic Fields [Elektronische Daten] [J. McLaughlin, A. Hood, I. De Moortel] We present a comprehensive review of MHD wave behaviour in the neighbourhood of coronal null points: locations where the magnetic field, and hence the local Alfvén speed, is zero. The behaviour of all three MHD wave modes, i.e. the Alfvén wave and the fast and slow magnetoacoustic waves, has been investigated in the neighbourhood of 2D, 2.5D and (to a certain extent) 3D magnetic null points, for a variety of assumptions, configurations and geometries. In general, it is found that the fast magnetoacoustic wave behaviour is dictated by the Alfvén-speed profile. In a β=0 plasma, the fast wave is focused towards the null point by a refraction effect and all the wave energy, and thus current density, accumulates close to the null point. Thus, null points will be locations for preferential heating by fast waves. Independently, the Alfvén wave is found to propagate along magnetic fieldlines and is confined to the fieldlines it is generated on. As the wave approaches the null point, it spreads out due to the diverging fieldlines. Eventually, the Alfvén wave accumulates along the separatrices (in 2D) or along the spine or fan-plane (in 3D). Hence, Alfvén wave energy will be preferentially dissipated at these locations. It is clear that the magnetic field plays a fundamental role in the propagation and properties of MHD waves in the neighbourhood of coronal null points. This topic is a fundamental plasma process and results so far have also lead to critical insights into reconnection, mode-coupling, quasi-periodic pulsations and phase-mixing. Springer Science+Business Media B.V., 2010 Magnetic fields: coronal nationallicence Magnetic fields: models nationallicence Waves: magnetohydrodynamic nationallicence Waves: propagation nationallicence Magnetohydrodynamics nationallicence McLaughlin J. School of Mathematics and Statistics, University of St Andrews, KY16 9SS, St Andrews, UK aut Hood A. School of Mathematics and Statistics, University of St Andrews, KY16 9SS, St Andrews, UK aut De Moortel I. School of Mathematics and Statistics, University of St Andrews, KY16 9SS, St Andrews, UK aut Space Science Reviews Springer Netherlands 158/2-4(2011-07-01), 205-236 0038-6308 158:2-4<205 2011 158 11214 https://doi.org/10.1007/s11214-010-9654-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11214-010-9654-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- McLaughlin J. School of Mathematics and Statistics, University of St Andrews, KY16 9SS, St Andrews, UK aut NATIONALLICENCE 700 1- Hood A. School of Mathematics and Statistics, University of St Andrews, KY16 9SS, St Andrews, UK aut NATIONALLICENCE 700 1- De Moortel I. School of Mathematics and Statistics, University of St Andrews, KY16 9SS, St Andrews, UK aut NATIONALLICENCE 773 0- Space Science Reviews Springer Netherlands 158/2-4(2011-07-01), 205-236 0038-6308 158:2-4<205 2011 158 11214 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer