by Science Applications International Corp., National Aeronautics and Space Administration, National Technical Information Service, distributor in San Diego, Calif, [Washington, DC, Springfield, Va .
Written in English
|Statement||Zoran Mikić; principal investigator.|
|Series||NASA-CR -- 185477., NASA contractor report -- NASA CR-185477.|
|Contributions||United States. National Aeronautics and Space Administration.|
|The Physical Object|
technique" for the determination of force-free coronal magnetic fields from vector magnetograph observations. The method can successfully generate nonlinear force-free fields (with non-constant-o0 that match vector magnetograms. We demonstrated that it is possible to determine coronal magnetic fields . past for coronal magnetic field measurements[3,4]. Due to the requirement of highly sensitive polarimetry, low-scatter instrument and low sky background most of the past measurements are inconclusive. Recently Lin et al.[5,6] reported coronal magnetic field observations using a m off-axis reflecting coronagraph in conjunction with optical. During the course of the present contract we developed an 'evolutionary technique' for the determination of force-free coronal magnetic fields from vector magnetograph observations. The method can successfully generate nonlinear force- free fields (with non-constant-a) that match vector Author: Zoran Mikic. We report our recent improvement in non-force-free extrapolation of coronal magnetic field, using vector magnetograms. Based on the principle of minimum (energy) dissipation rate (MDR), a generally non-force-free magnetic field solution is expressed as the superposition of one potential field and two (constant-α) linear force-free fields, with distinct α parameters.
It shows an interconnecting system of hot coronal loops within and between two active regions on opposite sides of the Sun's equator. Panel (b) from Kitt Peak's magnetograph shows the line-of-sight magnetic field measurements with positive fields in white and negative fields . Abstract. We report our recent improvement in non-force-free extrapolation of coronal magnetic field, using vector magnetograms. Based on the principle of minimum (energy) dissipation rate (MDR), a generally non-force-free magnetic field solution is expressed as the superposition of one potential field and two (constant-[alpha]) linear force-free fields, with distinct [alpha] parameters. The magnetic virial theorem states that the magnetic energy contained in a coronal force-free magnetic field is given by a surface integral at the photospheric boundary involving the three vector. NOAO Newsletter - NOAO Highlights - December - Number Definitive Measurement of the Coronal Magnetic Field. Haosheng Lin. The magnetic field in the solar corona is generally believed to be responsible for a wide range of phenomena—from being the carrier of MHD waves to heat the corona, to producing the gyro-synchrotron radiation in the radio wavelength range.
In this work, we model the coronal magnetic field above multiple active regions using NLFFF extrapolation code using vector magnetograph data from the Synoptic Optical Long-term Investigations of the Sun survey (SOLIS)/ Vector Spectromagnetograph (VSM) as a boundary conditions. We compare projections of the resulting magnetic field lines. By 'vector' measurements we mean that the observation attempts to deduce the complete strength and direction of the field at the measurement site, rather than just the line of sight component as obtained by a traditional longitudinal magnetograph. Knowledge of the vector field permits one to calculate photospheric electric currents, which might. TRACING THE CHROMOSPHERIC AND CORONAL MAGNETIC FIELD WITH AIA, IRIS, IBIS, AND ROSA DATA and to determine their magnetic ﬁeld-alignment and non-potentiality (Jing from a vector magnetograph instrument as input for the photospheric boundary (in the (x, y)-plane), and use a height-extrapolation. A PRACTICAL APPROACH TO CORONAL MAGNETIC FIELD EXTRAPOLATION BASED ON THE PRINCIPLE OF MINIMUM DISSIPATION RATE given vector magnetograph measurements B at certain bottom levels on the solar surface. In order to evaluate The bottom two layers of the vector magnetic ﬁeld data are utilized to generate the bottom boundary z ¼ 0.