PPT-Solar magnetic fields: force-free fields

Anna Ania Malanushenko ForceFree Fields Know B in photosphere Want to know B in the corona Forcefree field definition Recall from the prev lecture neglect in the corona Equilibrium. In addition magnetic fields create a force only on moving charges The direction the magnetic field produced by a moving charge is perpendicular to the direction of motion The direction of the force due to a magnetic field is perpendicular to the dir . Astrophysics. II. Markus Roth. Fakultät für Mathematik und Physik. Albert-Ludwigs-Universität Freiburg. Kiepenheuer-Institut für Sonnenphysik. I. . Magnetohydrodynamics. (. for. . astrophysics. 8.5 – Applications of Electric and Magnetic Fields. Agenda. Quiz. Lesson on Section on 8.5. Lots of Video’s. Story Time. Cyclotron Particle Accelerator. http://. www.youtube.com/watch?v=cNnNM2ZqIsc. Dayal Wickramasinghe and Lilia . Ferrario. Australian National University. Canberra. . . The chemically peculiar . Ap. , Bp stars ( ~ 1.8 -5 . M. sun. ) are magnetic, and . have ordered large. scale fields, . Andrii Neronov. University of Geneva. Durrer. & AN, . A&ARev. , 21, 62 (2013) . Overview . Magnetic fields in astronomy and cosmology. Characterization. of cosmological magnetic fields. Generation. to . their CME . progenitors (Wed AM). Two major efforts are under way to address the structure of CMEs that hit the Earth, and . B. z. in particular, with the long-term goal of better forecasting geomagnetic storms:. chromospheric. field information in. coronal field extrapolation?. Current state of art are nonlinear force-free. extrapolations of measured photospheric field vector.. Direct measurements of chromospheric fields in combination with self-consistent MHD-models are. a physical perspective . . 1. Philip Judge, . . High Altitude Observatory, NCAR. "Double, double, toil and trouble;. Fire burn, and cauldron bubble!". -- . . Astrophysics. II. Markus Roth. Fakultät für Mathematik und Physik. Albert-Ludwigs-Universität Freiburg. Kiepenheuer-Institut für Sonnenphysik. I. . Magnetohydrodynamics. (. for. . astrophysics. basic concepts and magnetic topology . Anna (. Ania. ) . Malanushenko. Plasma. Is matter…. Mass is conserved. Momentum is conserved. Energy is conserved. …ionized and in magnetic field. Obeys Maxwell’s equations. all magnets have magnetic poles – . . points at the ends of a magnet that have opposing magnetic qualities. all magnets have a north pole and south pole that are magnetically opposite. like poles repel and unlike poles attract. 21. History of Magnetism . In 1269, Pierre de Maricourt of France found that the directions of a needle near a spherical natural magnet formed lines that encircled the sphere and passed through two points diametrically opposite each other, which he called the poles of the magnet. Subsequent experiments showed that every magnet, regardless of its shape, has two poles, called North (N) and (S) poles, that exert forces on other magnetic poles similar to the way electric charges exert forces on one another. That is, like poles (N-N or S-S) repel each other, and opposite poles (N-S) attract each other. Systems. Frank Barnes.  . Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, Colorado. Acknowledgement. Ben Greenebaum. . Lucas Portelli . Carlos Martino . Open: Venus – solar wind. Closed: Venus – Venus. Draped: solar wind – solar wind. Magnetic fields guide ion and electron motions. The connectivity (topology) of these field lines helps us to understand how the upper atmosphere interacts with the solar wind..