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Related papers: Decorrelation Times of Photospheric Fields and Flo…

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Flare-prolific active region NOAA 12673 produced consecutive X2.2 and X9.3 flares on 06/09/2017. To scrutinize the morphological, magnetic, and horizontal flow properties associated with these flares, a 7-hour time-series was used…

Solar and Stellar Astrophysics · Physics 2018-05-09 M. Verma

Flows on the solar surface are linked to solar activity, and LCT is one of the standard techniques for capturing the dynamics of these processes by cross-correlating solar images. However, the link between contrast variations in successive…

Solar and Stellar Astrophysics · Physics 2015-06-16 M. Verma , M. Steffen , C. Denker

We describe a method to study the rate at which modes decorrelate in numerical simulations. We study the XY model updated with the Metropolis and Wolff dynamics respectively and compute the rate at which each eigenvector of the dynamics…

High Energy Physics - Lattice · Physics 2009-10-22 R. Ben-Av , G. Bhanot

Active regions (ARs) play an important role in the magnetic dynamics of the Sun. Solar surface flux transport models (SFTMs) are used to describe the evolution of the radial magnetic field at the solar surface. There is however uncertainty…

Solar and Stellar Astrophysics · Physics 2022-03-30 Nils Gottschling , Hannah Schunker , Aaron C. Birch , Robert Cameron , Laurent Gizon

Measurements of the variation of anisotropic flow-plane angles ($\Psi_n$) with rapidity, commonly known as the flow-plane decorrelation, provide important insights into the initial conditions of the matter produced in heavy-ion collisions.…

Nuclear Experiment · Physics 2026-01-16 STAR Collaboration

The coronal magnetic field evolution of 20 bipolar active regions (ARs) is simulated from their emergence to decay using the time-dependent nonlinear force-free field method of Mackay et al. A time sequence of cleaned photospheric…

Solar and Stellar Astrophysics · Physics 2021-01-13 Stephanie L. Yardley , Duncan H. Mackay , Lucie M. Green

Investigating the early-stage evolution of an erupting flux rope from the Sun is important to understand the mechanisms of how it looses its stability and its space weather impacts. Our aim is to develop an efficient scheme for tracking the…

Solar and Stellar Astrophysics · Physics 2023-09-13 Andreas Wagner , Emilia K. J. Kilpua , Ranadeep Sarkar , Daniel J. Price , Anshu Kumari , Farhad Daei , Jens Pomoell , Stefaan Poedts

Sunspots are regions of decreased brightness on the visible surface of the Sun (photosphere) that are associated with strong magnetic fields. They have been found to be locations associated with solar flares, which occur when energy stored…

Solar and Stellar Astrophysics · Physics 2013-01-24 Sophie A. Murray

The dynamics of fluctuations in a fast rotating spherical Couette flow experiment in the presence of a strong dipolar magnetic field is investigated in detail, through a thorough analysis of the experimental data as well as a numerical…

Geophysics · Physics 2016-01-22 Denys Schmitt , Philippe Cardin , Patrick La Rizza , Henri-Claude Nataf

Fluctuation dynamos occur in most turbulent plasmas in astrophysics and are the prime candidates for amplifying and maintaining cosmic magnetic fields. A few analytical models exist to describe their behaviour but they are based on…

Astrophysics of Galaxies · Physics 2023-07-03 Yann Carteret , Dominik Schleicher , Jennifer Schober

We measure the horizontal subsurface flow in a fast emerging active region (NOAA 11158) using the ring-diagram technique and the HMI high-spatial resolution Dopplergrams. This active region had a complex magnetic structure and displayed…

Solar and Stellar Astrophysics · Physics 2015-08-04 Kiran Jain , S. C. Tripathy , F. Hill

By using recent developments for the Langevin dynamics of spatially asymmetric systems, we routinely generalize the Onsager-Machlup fluctuation theory of the second order in time. In this form, it becomes applicable to fluctuating…

Statistical Mechanics · Physics 2016-12-28 Roman Belousov , E. G. D. Cohen

In a previous work, we investigated the evolution of the flow field around sunspots during sunspot decay and compared it with the flow field of supergranular cells. The decay of a sunspot proceeds as it interacts with its surroundings. This…

Solar and Stellar Astrophysics · Physics 2022-08-31 Hanna Strecker , Nazaret Bello González

Magnetic fluctuations with a zero mean field in a random flow with a finite correlation time and a small yet finite magnetic diffusion are studied. Equation for the second-order correlation function of a magnetic field is derived. This…

Astrophysics · Physics 2009-11-07 N. Kleeorin , I. Rogachevskii , D. Sokoloff

Using test-particle simulations, we investigate the temporal dependence of the two-point velocity correlation function for charged particles scattering in a time-independent spatially fluctuating magnetic field derived from a…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Federico Fraschetti , Joe Giacalone

Coronal magnetic fields evolve quasi statically over long time scales and dynamically over short time scales. As of now there exists no regular measurements of coronal magnetic fields, and therefore generating the coronal magnetic field…

Solar and Stellar Astrophysics · Physics 2023-12-20 P. Vemareddy , Jörn Warnecke , Ph. A. Bourdin

We report on the simultaneous and localized measurements of the diffusion coefficient and flow velocity based on the normalized autocorrelation function using optical coherence tomography (OCT). Our results on a flowing solution of…

Optics · Physics 2015-02-05 Nicolás Weiss , Ton G. van Leeuwen , Jeroen Kalkman

Context: One aspect of understanding the dynamics of the quiet Sun is to quantify the evolution of the flux within small-scale magnetic features. These features are routinely observed in the quiet photosphere and were given various names,…

Solar and Stellar Astrophysics · Physics 2015-02-04 R. Attie , D. E. Innes

The emergence of magnetic flux, its transition to complex configurations, and the pre-eruptive state of active regions are probed using photospheric magnetograms. We aim to pinpoint different evolutionary stages in active regions, explore…

Solar and Stellar Astrophysics · Physics 2024-11-06 I. Kontogiannis , A. G. M. Pietrow , M. K. Druett , E. Dineva , M. Verma , C. Denker

We studied the solar surface flows (differential rotation and meridional circulation) using a magnetic element feature tracking technique by which the surface velocity is obtained using magnetic field data. We used the line-of-sight…

Solar and Stellar Astrophysics · Physics 2018-09-05 Shinsuke Imada , Masashi Fujiyama