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Recent numerical work in helioseismology has shown that a periodically varying subsurface magnetic field leads to a fanning of the $f$-mode, which emerges from the density jump at the surface. In an attempt to model a more realistic…

Solar and Stellar Astrophysics · Physics 2019-12-16 Nishant K. Singh , Harsha Raichur , Maarit J. Käpylä , Matthias Rheinhardt , Axel Brandenburg , Petri J. Käpylä

In a force-free magnetic field, there is no interaction of field and the plasma in the surrounding atmosphere i.e., electric currents are aligned with the magnetic field, giving rise to zero Lorentz force. The computation of many magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-20 Sanjiv Kumar Tiwari

Solar flares are intense bursts of electromagnetic radiation, which occur due to a rapid destabilization and reconnection of the magnetic field. While pre-flare signatures and trends have been investigated from magnetic observations prior…

Solar and Stellar Astrophysics · Physics 2025-06-18 Kara L. Kniezewski , Emily I. Mason , Daniel J. Emmons , Kyle E. Fitch , Seth H. Garland

Global magnetohydrodynamic (MHD) models play an important role in the infrastructure of space weather forecasting. Validating such models commonly utilizes in situ solar wind measurements made near the orbit of the Earth. The purpose of…

Solar and Stellar Astrophysics · Physics 2024-10-31 Chin-Chun Wu , Kan Liou , Brian E. Wood , Y. M. Wang

Gaussian process regression has recently emerged as a powerful, system-agnostic tool for building global potential energy surfaces (PES) of polyatomic molecules. While the accuracy of GP models of PES increases with the number of potential…

Chemical Physics · Physics 2019-07-23 Jun Dai , Roman V. Krems

Although it is generally believed that the solar photosphere is not magnetically force-free owning to its high plasma $\beta$, the estimations of force-freeness using observed magnetograms have produced disputable results. Some studies…

Solar and Stellar Astrophysics · Physics 2023-09-28 Mei Zhang , Haocheng Zhang

We model the structure of the surface magnetic fields of the hydrogen-rich white dwarfs in the SDSS. We have calculated a grid of state-of-the-art theoretical optical spectra of hydrogen-rich magnetic white dwarfs with magnetic field…

Solar and Stellar Astrophysics · Physics 2015-05-13 B. Kulebi , S. Jordan , F. Euchner , B. Gaensicke , H. Hirsch

This white paper advocates the importance of multi-height measurements of the vector magnetic field in the solar atmosphere. As briefly described in this document, these measurements are critical for addressing some of the most fundamental…

Instrumentation and Methods for Astrophysics · Physics 2022-09-13 L. Bertello , N. Arge , A. G. De Wijn , S. Gosain , C. Henney , K. D. Leka , J. Linker , Y. Liu , J. Luhmann , P. J. Macniece , G. Petrie , A. Pevtsov , A. A. Pevtsov

Downscaling (DS) of meteorological variables involves obtaining high-resolution states from low-resolution meteorological fields and is an important task in weather forecasting. Previous methods based on deep learning treat downscaling as a…

Computer Vision and Pattern Recognition · Computer Science 2024-01-23 Zili Liu , Hao Chen , Lei Bai , Wenyuan Li , Keyan Chen , Zhengyi Wang , Wanli Ouyang , Zhengxia Zou , Zhenwei Shi

Spectroscopic surveys allow spatially resolved spectroscopy of galaxies to study their interstellar medium (ISM). However, observations of Galactic H$\alpha$ emission are contaminated by geocoronal H$\alpha$ emission. The latter is known to…

Instrumentation and Methods for Astrophysics · Physics 2026-02-03 Wai-Kiu Ricky Wong , Renbin Yan , Zesen Lin

We study the relationship between full-disk solar radiative flux at different wavelengths and average solar photospheric magnetic-flux density, using daily measurements from the Kitt Peak magnetograph and other instruments extending over…

Solar and Stellar Astrophysics · Physics 2010-06-23 Dora Preminger , Dibyendu Nandy , Gary Chapman , Petrus C. H. Martens

The source fluence distribution of terrestrial gamma ray flashes (TGFs) has been extensively discussed in recent years, but few have considered how the TGF fluence distribution at the source, as estimated from satellite measurements,…

Space Physics · Physics 2016-05-25 R. S. Nisi , N. Østgaard , T. Gjesteland , A. B. Collier

Knowledge of the global magnetic field distribution and its evolution on the Sun's surface is crucial for modeling the coronal magnetic field, understanding solar wind dynamics, computing the heliospheric open flux distribution and…

Solar and Stellar Astrophysics · Physics 2024-09-24 Soumyaranjan Dash , Marc L. DeRosa , Mausumi Dikpati , Xudong Sun , Sushant S. Mahajan , Yang Liu , J. Todd Hoeksema

We derive a first order linear differential equation describing the shape of the probability density function of magnetic field strengths in the quiet Sun (PDF). The modeling is very schematic. It considers convective motions which…

Astrophysics · Physics 2008-11-26 J. Sanchez Almeida

Faraday rotation studies of distant radio sources can constrain the evolution and the origin of cosmic magnetism. We use data from the LOFAR Two Metre Sky Survey: Data Release 2 (LoTSS DR2) to study the dependence of the Faraday rotation…

Recent advancements in diffusion models have been leveraged to address inverse problems without additional training, and Diffusion Posterior Sampling (DPS) (Chung et al., 2022a) is among the most popular approaches. Previous analyses…

Computer Vision and Pattern Recognition · Computer Science 2025-06-04 Tongda Xu , Xiyan Cai , Xinjie Zhang , Xingtong Ge , Dailan He , Ming Sun , Jingjing Liu , Ya-Qin Zhang , Jian Li , Yan Wang

Received: 1st December 2018; Accepted: 18th February 2019; Published: 1st April 2019 Abstract: The calculated filling factors (FFs) for a feature reflect the fraction of the solar disc covered by that feature, and the assignment of…

Solar and Stellar Astrophysics · Physics 2019-04-03 Amro F. Alasta , Abdrazag Algamudi , Fatma Almesrati , Mustapha Meftah , Rami Qahwaji

We have developed a general framework for modeling gyrosynchrotron and free-free emission from solar flaring loops and used it to test the premise that 2D maps of source parameters, particularly magnetic field, can be deduced from spatially…

Solar and Stellar Astrophysics · Physics 2015-06-15 Dale E. Gary , Gregory D. Fleishman , Gelu M. Nita

To estimate the hemispheric flux generation rate of the large-scale radial magnetic field in the Solar Cycles 23 and 24, we use the photospheric observations of the solar magnetic fields and results of the mean-field dynamo models. Results…

Solar and Stellar Astrophysics · Physics 2024-08-12 V. V. Pipin

The Subaru Prime Focus Spectrograph (PFS) is a massively-multiplexed fiber-fed optical and near-infrared 3-arm spectrograph (N_fiber=2400, 380<lambda<1260nm, 1.3 degree diameter FoV), offering unique opportunities in survey astronomy. Here…

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