3 edition of Determination of the coronal magnetic field from vector magnetograph data found in the catalog.
Determination of the coronal magnetic field from vector magnetograph data
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|
vector magnetogram from a level of the active region at and above which the magnetic field is force free. However, this approach cannot yet be used because all routinely provided vector magnetograms currently available are too inaccurate, or are of the non‐force‐free photosphere, or both [e.g., Gary et al., ; Klimchuk et al., •The magnitude of a magnetic fields produced by a long straight wire with a constant current is given by •Where B is the magnetic field, I is the current, r is the distance away from the wire, and is called the permeability of free space. •Magnetic fields are measured in Teslas(T). The Earth has a magnetic field .
Mikic Z, McClymont AN () Deducing coronal magnetic fields from vector magnetograms. In: Balasubramaniam KS, Simon GW (eds) Solar active region evolution: comparing models with observations, astronomical society of the pacific conference series, p Google Scholar. sure of the nonpotentiality of the magnetic field in any given pixel of a vector magnetogram is the angle between the ob- served transverse field and the potential transverse field, the shear angle. The extent to which the field along the main XAlso at Department of Physics, University of Alabama in Hunts- ville.
Methods for determination of coronal magnetic fields .. Field extrapolations: Why measurements are needed instead .. 2 Forbidden Lines As Diagnostics Of The Coronal Magnetic field A brief history of forbidden line spectroscopy. Mission concepts to help determine the incoming CME ﬁeld from solar observations to enable 24h forecasts of space weather Karel Schrijver(a) and Jon Linker(b) (a) Lockheed Martin Advanced Technology Center, Palo Alto, CA; (b) Predictive Sciences, San Diego, CA The intensity of CME-related space weather is a function of the structure of the magnetic ﬁeld impacting the terrestrial environment.
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DETERMINATION OF THE CORONAL MAGNETIC FIELD FROM VECTOR MAGNETOGRAPH DATA. i t /,J Science Applications International Coqx_tion An Employee-Owned Company Final Report on work performed under contract NASW with NASA (Solar Physics Supporting Research and Technology) ZORAN MIKIC, Principal Investigator.
Get this from a library. Determination of the coronal magnetic field from vector magnetograph data: final report. [Zoran Mikic; United States. National Aeronautics and Space Administration.]. 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. The application of supercomputers and advanced numerical techniques to problems of coronal structure and dynamics is described.
Numerical methods appr. Previous efforts to construct solar coronal fields using surface magnetograph data have generally employed a least squares minimization technique in order to determine the spherical harmonic expansion coefficients of the magnetic scalar potential. Provided there is no source surface high up in the corona, we show that knowledge of the line-of-sight component of the surface magnetic field, B i.
In this work, we model the coronal magnetic field above multiple active regions using NLFFF extrapolation code using vector magnetograph data from. The solar chromospheric and coronal magnetic fields play a major role in the physics of the solar atmosphere.
So lytical or/and numerical methods for the determination of the magnetic field in half the space above the pho- Starting from the vector magnetograph data at the photosphere (Say, z. data. In principle vector magnetograph data provides a set of boundary values for modelling the overlying coronal ﬁeld, but in practice basic diﬃ-culties prevent the construction of reliable models from the data.5,22 The nonlinear force-free model The nonlinear force-free model, involving a static balance of purely mag.
Measurements of coronal magnetic field strength on the solar disk. spectroscopic coronagraph to measure shocks in low corona space-based force-free full-disk vector magnetograph Discussion Summary: Group B –Solar Active Regions And Their Production of Flares and Coronal Mass Ejections Discussion Leaders: George Fisher Hugh Hudson Our.
Knowledge regarding the coronal magnetic field is important for the understanding of many phenomena, like flares and coronal mass ejections.
Because of the low.The contemporary vector magnetographs pro-vide su cient data on the linear and circular polar-ization of light to recover all three magnetic vector components on the photosphere.
These photospheric magnetic eld distributions are now used as bound-ary conditions in computations of adjacent coronal magnetic eld topologies and their comparisons with.Get this from a library! Determination of coronal magnetic fields from vector magnetograms: final progress report.
[Zoran Mikic; United States. National Aeronautics and Space Administration.].