Solar Physics最新文献

{"title":"Data Processing Pipeline of the SUTRI EUV Imager on the SATech-01 Satellite","authors":"Ziyao Hu,&nbsp;Kaifan Ji,&nbsp;Xianyong Bai,&nbsp;Xiao Yang,&nbsp;Yuanyong Deng,&nbsp;Wei Duan,&nbsp;Zhenyong Hou,&nbsp;Zihao Yang","doi":"10.1007/s11207-025-02483-3","DOIUrl":"10.1007/s11207-025-02483-3","url":null,"abstract":"<div><p>Solar observations in extreme ultraviolet (EUV) wavelengths are a crucial component of solar activity research and space weather forecasting. The Solar Upper Transition Region Imager (SUTRI) on the SATech-01 satellite is designed to take full-disk solar images in the Ne <span>vii</span> 46.5 nm spectral line (T = 0.5 MK). It was launched in 2022 and the science data were released on January 10, 2023. In this article, we describe the data preprocessing method employed to SUTRI data to eliminate inherent instrument effects and standardize the raw data to obtain scientific data. Alongside common data processing steps, our pipeline includes correcting for horizontal stripes from the CMOS imaging camera. As an experiment payload, SUTRI does not have an image stabilization system. Thus, a multi-step iterative algorithm has been developed to precisely align series of drifted images due to the limited pointing accuracy of the satellite platform. Our method may not be limited to SUTRI; it also serves as a reference for future solar EUV telescope data processing.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11207-025-02483-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144140126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure and Dynamics of the Sun’s Interior Revealed by the Helioseismic and Magnetic Imager","authors":"Alexander G. Kosovichev,&nbsp;Sarbani Basu,&nbsp;Yuto Bekki,&nbsp;Juan Camilo Buitrago-Casas,&nbsp;Theodosios Chatzistergos,&nbsp;Ruizhu Chen,&nbsp;Jørgen Christensen-Dalsgaard,&nbsp;Alina Donea,&nbsp;Bernhard Fleck,&nbsp;Damien Fournier,&nbsp;Rafael A. García,&nbsp;Alexander V. Getling,&nbsp;Laurent Gizon,&nbsp;Douglas O. Gough,&nbsp;Shravan Hanasoge,&nbsp;Chris S. Hanson,&nbsp;Shea A. Hess Webber,&nbsp;J. Todd Hoeksema,&nbsp;Rachel Howe,&nbsp;Kiran Jain,&nbsp;Spiridon Kasapis,&nbsp;Samarth G. Kashyap,&nbsp;Irina N. Kitiashvili,&nbsp;Rudolf Komm,&nbsp;Sylvain G. Korzennik,&nbsp;Natalie A. Krivova,&nbsp;Jeffrey R. Kuhn,&nbsp;Zhi-Chao Liang,&nbsp;Charles Lindsey,&nbsp;Sushant S. Mahajan,&nbsp;Krishnendu Mandal,&nbsp;Prasad Mani,&nbsp;Juan Carlos Martinez Oliveros,&nbsp;Savita Mathur,&nbsp;M. Cristina Rabello Soares,&nbsp;S. Paul Rajaguru,&nbsp;Johann Reiter,&nbsp;Edward J. Rhodes Jr.,&nbsp;Jean-Pierre Rozelot,&nbsp;Philip H. Scherrer,&nbsp;Sami K. Solanki,&nbsp;John T. Stefan,&nbsp;Juri Toomre,&nbsp;Sushanta C. Tripathy,&nbsp;Lisa A. Upton,&nbsp;Junwei Zhao","doi":"10.1007/s11207-025-02480-6","DOIUrl":"10.1007/s11207-025-02480-6","url":null,"abstract":"<div><p>High-resolution helioseismology observations with the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) provide a unique three-dimensional view of the solar interior structure and dynamics, revealing a tremendous complexity of the physical processes inside the Sun. We present an overview of the results of the HMI helioseismology program and discuss their implications for modern theoretical models and simulations of the solar interior.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11207-025-02480-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144135280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linear Correlation Between Radial and Normal Component Fluctuations of the Interplanetary Magnetic Field","authors":"Munetoshi Tokumaru,&nbsp;Nishiki Nozaki,&nbsp;Ken’ichi Fujiki","doi":"10.1007/s11207-025-02475-3","DOIUrl":"10.1007/s11207-025-02475-3","url":null,"abstract":"<div><p>The interplanetary magnetic field (IMF), particularly its north–south component, acts as a key parameter for controlling the space weather effect of solar wind disturbances on the Earth; therefore, accurate understanding of the behavior of the IMF is important for improvement of space weather prediction. This study reports the relation between radial (<span>(B_{r})</span>) and normal (<span>(B_{n})</span>) components of IMF by analyzing in situ observations collected by inner- and outer-heliosphere spacecraft over multiple solar cycles. A quadratic relation between <span>(B_{r})</span> and <span>(B_{n})</span> with a 22-year periodicity which corresponds to the magnetic polarity cycle of the Sun was observed in IMF data of the inner-heliosphere spacecraft. In contrast, IMF data of the outer-heliosphere spacecraft did not show such a quadratic relation but exhibited a linear relation between <span>(B_{r})</span> and <span>(B_{n})</span> with a slope and correlation coefficient depending on the latitude: positive and negative slopes (correlation coefficients) were revealed from the IMF data for north and south latitudes, respectively, and those magnitudes increased with the latitude. Slopes and correlation coefficients of the linear relation depended on neither the radial distance nor the solar activity. The same linear relation between <span>(B_{r})</span> and <span>(B_{n})</span> was found for the IMF data of the inner-heliosphere spacecraft by sorting them into two groups in terms of the latitude. Therefore, quadratic relation was ascribed to the combined effect of the latitude variation of the inner-heliosphere spacecraft and the latitude dependence of the linear relation. Although the physical process to generate the linear relation remains an open question, some kind of MHD waves may be responsible for it.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11207-025-02475-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144140203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of Polar Magnetic Fields Derived from MILOS and MERLIN Inversions with Hinode/SOT-SP Data","authors":"Masahito Kubo,&nbsp;Daikou Shiota,&nbsp;Yukio Katsukawa,&nbsp;Masumi Shimojo,&nbsp;David Orozco Suárez,&nbsp;Nariaki Nitta,&nbsp;Marc DeRosa,&nbsp;Rebecca Centeno,&nbsp;Haruhisa Iijima,&nbsp;Takuma Matsumoto,&nbsp;Satoshi Masuda","doi":"10.1007/s11207-025-02487-z","DOIUrl":"10.1007/s11207-025-02487-z","url":null,"abstract":"<div><p>The detailed investigation of the polar magnetic field and its time evolution is one of the major achievements of Hinode. Precise measurements of the polar magnetic field are essential for understanding the solar cycle, as they provide important constraints for identifying the source regions of the solar wind. The Spectropolarimeter (SP) of the Solar Optical Telescope (SOT) on board Hinode has been the instrument best suited to make such measurements. In this study, we compare the SOT-SP data for the polar regions, processed using two representative Milne-Eddington inversion codes, MILOS and MERLIN. These codes are applied to the same level-1 SOT-SP data, and the same disambiguation algorithm is used on the maps that go through the two inversions. We find that the radial magnetic-flux density (the magnetic-flux density with respect to the local vertical) provided by the MERLIN inversion tends to be approximately 7% – 10% larger than that obtained from the MILOS inversion. The slightly higher radial magnetic-flux density from MERLIN appears to be common to the polar magnetic fields observed at different phases of the solar cycle. When MILOS is run with the same scattered-light profile and the same magnetic filling factor that are derived with the MERLIN inversion, the radial magnetic-flux density derived from the two inversions is almost the same. We attribute the difference in the radial magnetic-flux density to different filling factors adopted by the two inversions, based on whether the scattered-light profiles are assumed to be the Stokes I profiles averaged over the neighboring pixels or over the entire field of view. The relationship between the radial magnetic-flux density and magnetic filling factor could be more complex in the polar (limb) observations due to the possible contributions of the transverse magnetic-field component to the estimation of the radial magnetic-flux density.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144125859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linear Analysis of Shear-Flow Instabilities in a Prominence-Corona Interface with Ambipolar Diffusion","authors":"Llorenç Melis,&nbsp;Roberto Soler","doi":"10.1007/s11207-025-02481-5","DOIUrl":"10.1007/s11207-025-02481-5","url":null,"abstract":"<div><p>Observations have shown the presence of the Kelvin–Helmholtz instability (KHi) in solar prominences. Effects due to partial ionization of the prominence plasma may influence the KHi onset. We study the triggering of the KHi in an interface model that consists of a partially ionized prominence region and a fully ionized coronal region, with a uniform magnetic field parallel to the interface. There is a longitudinal flow in the prominence region. The plasma is compressible and the role of ambipolar diffusion, which accounts for collisions between charges and neutrals, is taken into account in the prominence plasma. We derive the dispersion relation of linear perturbations on the interface and analyze some limit cases analytically. Numerical results are obtained for realistic prominence parameters. We find that compressibility and gas pressure are important in determining the unstable flow velocities, specially in the range of sub-Alfvénic flows that are consistent with the observations. The ambipolar diffusion has a generally destabilizing influence and reduces the threshold flow velocity for the KHi onset.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11207-025-02481-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144117698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Visible Emission Line Coronagraph (VELC) on Board Aditya-L1","authors":"Jagdev Singh,&nbsp;R. Ramesh,&nbsp;B. Raghavendra Prasad,&nbsp;V. Muthu Priyal,&nbsp;K. Sasikumar Raja,&nbsp;S. N. Venkata,&nbsp;P. U. Kamath,&nbsp;V. Natarajan,&nbsp;S. Pawankumar,&nbsp;V. U. Sanal Krishnan,&nbsp;P. Savarimuthu,&nbsp;Shalabh Mishra,&nbsp;Varun Kumar,&nbsp;Chavali Sumana,&nbsp;S. Bhavana Hegde,&nbsp;D. Utkarsha,&nbsp;Amit Kumar,&nbsp;S. Nagabhushana,&nbsp;S. Kathiravan,&nbsp;P. Vemareddy,&nbsp;C. Kathiravan,&nbsp;K. Nagaraju,&nbsp;Belur Ravindra,&nbsp;Wageesh Mishra","doi":"10.1007/s11207-025-02477-1","DOIUrl":"10.1007/s11207-025-02477-1","url":null,"abstract":"<div><p>Aditya-L1, India’s first dedicated mission to study the Sun and its atmosphere from the Sun-Earth Lagrangian L1 location was successfully launched on September 2, 2023. It carries seven payloads. The Visible Emission Line Coronagraph (VELC) is a major payload on Aditya-L1. VELC is designed to carry out imaging and spectroscopic observations (the latter in three emission lines of the corona), simultaneously. Images of the solar corona in the continuum at 5000 Å, with a field of view (FoV) from 1.05 <span>(mathrm{R}_{odot })</span> to 3 <span>(mathrm{R}_{odot })</span> can be obtained at variable intervals depending on the data volume that can be downloaded. Spectroscopic observations of the solar corona in three emission lines, namely 5303 Å Fe<span>xiv</span>, 7892 Å Fe<span>xi</span>, and 10,747 Å Fe<span>xiii</span> are possible simultaneously, with different exposure times and cadence. Four slits, each of width 50 <span>({ mu })</span>m, separated by 3.75 mm help to simultaneously obtain spectra at four positions in the solar corona in all the aforementioned lines. A Linear Scan Mechanism (LSM) makes it possible to scan the solar corona up to ± 1.5 <span>(mathrm{R}_{odot })</span>. The instrument has the facility to carry out spectropolarimetric observations at 10,747 Å also in the FoV range 1.05 – 1.5 <span>(mathrm{R}_{odot })</span>. Various components of the instrument were tested interferometrically on the optical bench before installation. The individual components were aligned and performance of the payload was checked in the laboratory using a laser source and tungsten lamp. Wavelength calibration of the instrument was verified using the Sun as a light source. All the detectors were calibrated for different parameters such as dark current and its variation with exposure time. Here, we discuss the various features of the VELC, alignment, calibration, performance, possible observations, initial data analysis, and results of initial tests conducted in-orbit.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144100266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Potential Field Source Surface and Non-linear Force-Free Field Extrapolation to Model Magnetic Field Structure for a Giant Solar Filament","authors":"Abbi S. Demissie,&nbsp;Tilaye Tadesse,&nbsp;Araya Asfaw,&nbsp;Tong Shi","doi":"10.1007/s11207-025-02474-4","DOIUrl":"10.1007/s11207-025-02474-4","url":null,"abstract":"<div><p>Solar filaments are intriguing structures suspended in the solar corona at heights up to 100 Mm above the chromosphere, but they are made of chromospheric material which is one hundred times cooler and denser than the coronal material. Studying filament magnetic field structures, magnetic energy and electric current density is crucial to know its stability, because unstable conditions can result in explosive events like flares and coronal mass ejections (CMEs). A few recent studies have been conducted to model large-scale filaments in the quiet Sun though the majority of studies focus on modeling small-scale active region filaments. This study is the first to use potential field source surface (PFSS) and non-linear force-free field (NLFFF) models in spherical geometry to study a giant filament (with length more than 800 Mm) along a polarity inversion line (PIL) in a weak-field region (with photospheric field region of ≈ 50 G). The two modeling methods are applied to data obtained from a giant filament observation on February 10, 2015 with preprocessing of photospheric full-disk vector magnetograms from the Helioseismic and Magnetic Imager (HMI) and Vector Spectromagnetograph (VSM) using optimization procedure to make the boundary data more consistent with the force-free principle. The large-scale magnetic configuration surrounding the filament is derived from the PFSS model, while the NLFFF extrapolation provides a detailed three-dimensional structure of the filament using both HMI and VSM data. Results from both instruments show good agreement. The NLFFF extrapolation based on HMI data yields higher total and free magnetic energy compared to VSM data. Moreover, the total surface electric current density is greater with VSM data, consistent with the magnetic field strength derived from both instruments.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144100267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Sunrise Ultraviolet Spectropolarimeter and Imager: Instrument Description","authors":"Alex Feller,&nbsp;Achim Gandorfer,&nbsp;Bianca Grauf,&nbsp;Johannes Hölken,&nbsp;Francisco A. Iglesias,&nbsp;Andreas Korpi-Lagg,&nbsp;Tino L. Riethmüller,&nbsp;Jan Staub,&nbsp;German Fernandez-Rico,&nbsp;Juan Sebastián Castellanos Durán,&nbsp;Sami K. Solanki,&nbsp;H. N. Smitha,&nbsp;Kamal Sant,&nbsp;Peter Barthol,&nbsp;Montserrat Bayon Laguna,&nbsp;Melani Bergmann,&nbsp;Jörg Bischoff,&nbsp;Jan Bochmann,&nbsp;Stefan Bruns,&nbsp;Werner Deutsch,&nbsp;Michel Eberhardt,&nbsp;Rainer Enge,&nbsp;Sam Goodyear,&nbsp;Klaus Heerlein,&nbsp;Jan Heinrichs,&nbsp;Dennis Hirche,&nbsp;Stefan Meining,&nbsp;Roland Mende,&nbsp;Sabrina Meyer,&nbsp;Maria Mühlhaus,&nbsp;Marc Ferenc Müller,&nbsp;Markus Monecke,&nbsp;Dietmar Oberdorfer,&nbsp;Ioanna Papagiannaki,&nbsp;Sandeep Ramanath,&nbsp;Michael Vergöhl,&nbsp;Dušan Vukadinović,&nbsp;Stephan Werner,&nbsp;Andreas Zerr,&nbsp;Thomas Berkefeld,&nbsp;Pietro Bernasconi,&nbsp;Yukio Katsukawa,&nbsp;Jose Carlos del Toro Iniesta,&nbsp;Alexander Bell,&nbsp;Michael Carpenter,&nbsp;Alberto Álvarez Herrero,&nbsp;Masahito Kubo,&nbsp;Valentín Martínez Pillet,&nbsp;David Orozco Suárez","doi":"10.1007/s11207-025-02471-7","DOIUrl":"10.1007/s11207-025-02471-7","url":null,"abstract":"<div><p>The third science flight of the balloon-borne solar observatory <span>Sunrise</span> carries three entirely new post-focus science instruments with spectropolarimetric capabilities, concurrently covering an extended spectral range from the near ultraviolet to the near infrared. Sampling a larger height range, from the low photosphere to the chromosphere, with the sub-arcsecond resolution provided by the 1-m <span>Sunrise</span> telescope, is key in understanding critical small-scale phenomena which energetically couple different layers of the solar atmosphere. The <span>Sunrise</span> UV Spectropolarimeter and Imager (<span>SUSI</span>) operates between 309 nm and 417 nm. A key feature of <span>SUSI</span> is its capability to record up to several hundred spectral lines simultaneously without the harmful effects of the Earth’s atmosphere. The rich <span>SUSI</span> spectra can be exploited in terms of many-line inversions. Another important innovation of the instrument is the synchronized 2D context imaging which allows to numerically correct the spectrograph scans for residual optical aberrations. In this work we describe the main design aspects of <span>SUSI</span>, the instrument characterization and testing, and finally its operation, expected performance and data products.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11207-025-02471-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectral Irradiance Variability in Lyman-Alpha Emission During Solar Flares","authors":"Luke Majury,&nbsp;Ryan Milligan,&nbsp;Elizabeth Butler,&nbsp;Harry Greatorex,&nbsp;Maria Kazachenko","doi":"10.1007/s11207-025-02476-2","DOIUrl":"10.1007/s11207-025-02476-2","url":null,"abstract":"<div><p>The Lyman-alpha (Ly<span>(alpha )</span>; 1216 Å) line is the brightest emission line in the quiescent solar spectrum and radiates a significant fraction of the available nonthermal energy during flares. Despite its importance, there is a lack of detailed studies of Ly<span>(alpha )</span> spectral variability during flares. Recently, spectrally resolved Ly<span>(alpha )</span> flare observations from the SORCE/SOLSTICE instrument have become available. This study examines Ly<span>(alpha )</span> spectral variability and its relationship with HXR emission from nonthermal electrons, using observations of two M-class flares from SORCE/SOLSTICE and RHESSI. Imaging observations from STEREO/SECCHI EUVI and SDO/AIA provide further context. Enhancements across the Ly<span>(alpha )</span> line profile were found to closely correlate with bursts of HXR emission, suggesting a primarily nonthermal origin. Red enhancement asymmetries at the peak of each flare were attributed to chromospheric evaporation, while blue wing enhancement and blue asymmetry were linked to a bright filament-eruption seen in SDO/AIA 1600 Å images. These findings contribute to the understanding of spectral Ly<span>(alpha )</span> variability during flares and highlight the need for future studies using a higher quality and quantity of spectral Ly<span>(alpha )</span> flare observations. Such studies will further characterise the physical mechanisms driving Ly<span>(alpha )</span> flare variability.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11207-025-02476-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Efficient Method for Magnetic Field Extrapolation Based on a Family of Analytical Three-Dimensional Magnetohydrostatic Equilibria","authors":"Lilli Nadol,&nbsp;Thomas Neukirch","doi":"10.1007/s11207-025-02469-1","DOIUrl":"10.1007/s11207-025-02469-1","url":null,"abstract":"<div><p>With current observational methods it is not possible to directly measure the magnetic field in the solar corona with sufficient accuracy. Therefore, coronal magnetic field models have to rely on extrapolation methods using photospheric magnetograms as boundary conditions. In recent years, due to the increased resolution of observations and the need to resolve non-force-free lower regions of the solar atmosphere, there have been increased efforts to use magnetohydrostatic (MHS) field models instead of force-free extrapolation methods. Although numerical methods to calculate MHS solutions can deal with non-linear problems and hence provide more accurate models, analytical three-dimensional MHS equilibria can also be used as a numerically relatively “cheap” complementary method. In this paper, we present an extrapolation method based on a family of analytical MHS equilibria that allows for a transition from a non-force-free region to a force-free region. We demonstrate how asymptotic forms of the solutions can help to increase the numerical efficiency of the method. Through both artificial boundary condition testing and a first application to observational data, we validate the method’s effectiveness and practical utility.</p></div>","PeriodicalId":777,"journal":{"name":"Solar Physics","volume":"300 5","pages":""},"PeriodicalIF":2.7,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11207-025-02469-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143944256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}