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Related papers: Decorrelation Times of Photospheric Fields and Flo…

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The evolution of photospheric flow and magnetic fields before and after flares can provide important information regarding the flare triggering and back reaction processes. However, such studies on the flow field are rare due to the paucity…

Solar and Stellar Astrophysics · Physics 2018-02-14 Jiasheng Wang , Chang Liu , Na deng , Haimin Wang

The collective flow generated in relativistic heavy-ion collisions fluctuates from event to event. The fluctuations lead to a decorrelation of flow vectors measured in separate bins in phase space. These effects have been measured in…

Nuclear Theory · Physics 2024-02-21 Piotr Bozek , Hadi Mehrabpour

We tested whether simultaneous spectropolarimetric imaging in two magnetically sensitive optical spectral lines, which probe two different layers of the solar atmosphere (the photosphere and the temperature minimum), can help constrain the…

Flow, an optimal mental state merging action and awareness, significantly impacts our emotion, performance, and well-being. However, capturing its swift fluctuations on a fine timescale is challenging due to the sparsity of the existing…

Human-Computer Interaction · Computer Science 2023-12-29 Bohao Tian , Shijun Zhang , Sirui Chen , Yuru Zhang , Kaiping Peng , Hongxing Zhang , Dangxiao Wang

The coupled evolution of the magnetic field and the flow at the Earth's core mantle boundary is modeled within the 1900.0-2014.0 time period. To constraint the dynamical behavior of the system with a core field model deriving from direct…

We investigate the plasma and magnetic environment of active region NOAA 11261 on 2 August 2011 around a GOES M1.4 flare/CME (SOL2011-08-02T06:19). We compare coronal emission at (extreme) ultraviolet and X-ray wavelengths, using SDO AIA…

Solar and Stellar Astrophysics · Physics 2016-08-03 Julia K. Thalmann , Astrid M. Veronig , Yang Su

Ring-diagram analysis of acoustic waves observed at the photosphere can provide a relatively robust determination of the sub-surface flows at a particular time under a particular region. The depth of penetration of the waves is related to…

Solar and Stellar Astrophysics · Physics 2015-07-15 Richard S. Bogart , Charles S , . Baldner , Sarbani Basu

The Sun's axisymmetric flows, differential rotation and meridional flow, govern the dynamics of the solar magnetic cycle and variety of methods are used to measure these flows, each with its own strengths and weaknesses. Flow measurements…

Solar and Stellar Astrophysics · Physics 2021-09-08 Sushant S. Mahajan , David H. Hathaway , Andrés Muñoz-Jaramillo , Petrus C. Martens

We study the spatio-temporal behavior of the Els\"asser variables describing magnetic and velocity field fluctuations, using direct numerical simulations of three-dimensional magnetohydrodynamic turbulence. We consider cases with relatively…

A well-known property of solar wind plasma turbulence is the observed anisotropy of the autocorrelations, or equivalently the spectra, of velocity and magnetic field fluctuations. Here we explore the related but apparently not well-studied…

We demonstrate that extremely rapid and weak periodic and non-periodic signals can easily be detected by using the autocorrelation of intensity as a function of time. We use standard radio-astronomical observations that have artificial…

Instrumentation and Methods for Astrophysics · Physics 2018-05-16 Ermanno F. Borra , Jonathan D. Romney , Eric Trottier

Estimates of velocities from time series of photospheric and/or chromospheric vector magnetograms can be used to determine fluxes of magnetic energy (the Poynting flux) and helicity across the magnetogram layer, and to provide…

Astrophysics · Physics 2007-10-03 B. T. Welsch , G. H. Fisher

We explore the general properties of near-surface flows around solar active regions. Helioseismic holography is applied to HMI Dopplergrams yielding nearly 5000 flow measurements of 336 unique active regions observed by the Solar Dynamics…

Solar and Stellar Astrophysics · Physics 2019-03-20 D. C. Braun

In May 2024, the Sun exhibited intense magnetic activity, marked by numerous high-intensity flares resulting from the interaction and merging of NOAA ARs 13664 and 13668 in the southern hemisphere and AR 13663 in the northern hemisphere.…

Solar and Stellar Astrophysics · Physics 2025-07-04 B Lekshmi , Sushanta Tripathy , Kiran Jain , Alexei Pevtsov

Solar sub-surface fluid topology provides an indirect approach to examine the internal characteristics of active regions (ARs). Earlier studies have revealed the prevalence of strong flows in the interior of ARs having complex magnetic…

Solar and Stellar Astrophysics · Physics 2010-04-19 R. A. Maurya , A. Ambastha

Recently, we have developed a method useful for mapping large-scale horizontal velocity fields in the solar photosphere. The method was developed, tuned and calibrated using the synthetic data. Now, we applied the method to the series of…

Astrophysics · Physics 2009-11-13 Michal Svanda , Mirek Klvana , Michal Sobotka , Vaclav Bumba

Depth averaged conservation equations are written for granular surface flows. Their application to the study of steady surface flows in a rotating drum allows to find experimentally the constitutive relations needed to close these equations…

Condensed Matter · Physics 2016-02-26 D. Bonamy , F. Daviaud , L. Laurent

The initial energy density distribution and fluctuation in the transverse direction lead to anisotropic flows of final hadrons through collective expansion in high-energy heavy-ion collisions. Fluctuations along the longitudinal direction,…

Nuclear Theory · Physics 2016-05-04 Long-Gang Pang , Hannah Petersen , Guang-You Qin , Victor Roy , Xin-Nian Wang

Long-lived rotational and meridional flows are important ingredients of the solar cycle. Magnetic field images have typically been used to measure these flows on the solar surface by cross-correlating thin longitudinal strips or square…

Solar and Stellar Astrophysics · Physics 2017-02-15 Derek A. Lamb

Aims: Changes of the magnetic field and the line-of-sight velocities in the photosphere are being reported for an M-class flare that originated at a $\delta$-spot belonging to active region NOAA 11865. Methods: High-resolution ground-based…