Active Region-Based Full-Disc Solar Image Hashing

Quantum mechanics/molecular mechanics (QM/MM) methods partition the system into active and environmental regions and treat them with different levels of theory, achieving accuracy and efficiency at the same time. Adaptive-partitioning (AP) QM/MM methods allow on-the-fly changes to the QM/MM partitioning of the system. Many of the available energy-based AP-QM/MM methods partition the system according to distances to pre-chosen centers of active regions. For such AP-QM/MM methods, I develop an adaptive-center (AC) method that allows on-the-fly determination of the centers of active regions according to general geometrical or potential-related criteria, extending the range of application of energy-based AP-QM/MM methods to systems where active regions may occur or vanish during the simulation.

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TEXTURAL ANALYSIS OF AMPHIBOLITES AND SCHIST FROM THE CENTRAL VIRGINIA SEISMIC ZONE: CONSTRAINING THE PALEOZOIC TECTONIC FRAMEWORK IN A SEISMICALLY ACTIVE REGION

10.1130/abs/2017se-290354 ◽

2017 ◽

Author(s):

Mercer Parker ◽

◽

Mark W. Carter ◽

Ryan J. McAleer ◽

William C. Burton ◽

...

Keyword(s):

Active Region ◽

Textural Analysis ◽

Seismic Zone ◽

Tectonic Framework

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Characteristics of Soft X-Ray Radiation of the Solar Active Region NOAA 1024 Registered by the PINGVIN-M Device in July 2009

Geomagnetism and Aeronomy ◽

10.1134/s001679322007021x ◽

2020 ◽

Vol 60 (7) ◽

pp. 936-941

Author(s):

M. I. Savchenko ◽

P. V. Vatagin ◽

P. B. Dmitriev ◽

M. G. Ogurtsov ◽

E. M. Kruglov ◽

...

Keyword(s):

Active Region ◽

Solar Active Region ◽

Active Region Noaa ◽

X Ray ◽

Region Noaa

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Emission Measure Distribution for an Active Region Using Coordinated SERTS andYohkohSXT Observations

The Astrophysical Journal ◽

10.1086/307736 ◽

1999 ◽

Vol 523 (1) ◽

pp. 432-443 ◽

Cited By ~ 20

Author(s):

J. T. Schmelz ◽

J. L. R. Saba ◽

K. T. Strong ◽

H. D. Winter ◽

J. W. Brosius

Keyword(s):

Active Region ◽

Emission Measure ◽

Measure Distribution

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A high-resolution solar spectrum 2000 Å–2200 Å

Symposium - International Astronomical Union ◽

10.1017/s0074180900102165 ◽

1970 ◽

Vol 36 ◽

pp. 271-273

Author(s):

B. B. Jones ◽

B. C. Boland ◽

R. Wilson ◽

S. T. F. Engstrom

Keyword(s):

High Resolution ◽

Solar Spectrum ◽

Solar Image ◽

Roll Control ◽

North East ◽

The North ◽

Alignment System ◽

Optical Alignment ◽

South Axis ◽

System Operating

A high-resolution solar spectrum in the range 2000–2200 Å was obtained in a recent flight of a sunpointing Skylark rocket. This was launched at 04.21 hr UT on April 22, 1969 from Woomera and reached an apogee of 178 km. An optical alignment system operating on the main vehicle pointing system gave a net stabilisation of ±3 arc sec in the position of the solar image relative to the spectrograph slit. The slit, of length 1.0 mm, was set in the north-east quadrant parallel to and 5 arc min from the north/south axis, its lower edge being 1 arc min from the equator. The roll control of ±2.5° was provided entirely by the standard Elliott Bros. type of vehicle stabilisation.

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Energetics of magnetic transients in a solar active region plage

Astronomy and Astrophysics ◽

10.1051/0004-6361/201834548 ◽

2019 ◽

Vol 623 ◽

pp. A176 ◽

Cited By ~ 3

Author(s):

L. P. Chitta ◽

A. R. C. Sukarmadji ◽

L. Rouppe van der Voort ◽

H. Peter

Keyword(s):

Magnetic Field ◽

Active Region ◽

Magnetic Flux ◽

Numerical Simulations ◽

Extreme Ultraviolet ◽

Spatial Scales ◽

Coronal Loops ◽

The Sun ◽

Flux Emergence ◽

Transient Events

Context. Densely packed coronal loops are rooted in photospheric plages in the vicinity of active regions on the Sun. The photospheric magnetic features underlying these plage areas are patches of mostly unidirectional magnetic field extending several arcsec on the solar surface. Aims. We aim to explore the transient nature of the magnetic field, its mixed-polarity characteristics, and the associated energetics in the active region plage using high spatial resolution observations and numerical simulations. Methods. We used photospheric Fe I 6173 Å spectropolarimetric observations of a decaying active region obtained from the Swedish 1-m Solar Telescope (SST). These data were inverted to retrieve the photospheric magnetic field underlying the plage as identified in the extreme-ultraviolet emission maps obtained from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). To obtain better insight into the evolution of extended unidirectional magnetic field patches on the Sun, we performed 3D radiation magnetohydrodynamic simulations of magnetoconvection using the MURaM code. Results. The observations show transient magnetic flux emergence and cancellation events within the extended predominantly unipolar patch on timescales of a few 100 s and on spatial scales comparable to granules. These transient events occur at the footpoints of active region plage loops. In one case the coronal response at the footpoints of these loops is clearly associated with the underlying transient. The numerical simulations also reveal similar magnetic flux emergence and cancellation events that extend to even smaller spatial and temporal scales. Individual simulated transient events transfer an energy flux in excess of 1 MW m−2 through the photosphere. Conclusions. We suggest that the magnetic transients could play an important role in the energetics of active region plage. Both in observations and simulations, the opposite-polarity magnetic field brought up by transient flux emergence cancels with the surrounding plage field. Magnetic reconnection associated with such transient events likely conduits magnetic energy to power the overlying chromosphere and coronal loops.

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