English
Related papers

Related papers: Evolution of active region outflows throughout an …

200 papers

From 2022 March 18-21, active region (AR) 12967 was tracked simultaneously by Solar Orbiter (SO) at 0.35 au and Hinode/EIS at Earth. During this period, strong blue-shifted plasma upflows were observed along a thin, dark corridor of open…

Recent EUV spectroscopic observations indicate that slow magnetosonic waves are present in active region (AR) loops. Some of the spectral data were also interpreted as evidence of fast (~100-300 km/s) quasi-periodic flows. We have performed…

Solar and Stellar Astrophysics · Physics 2015-06-05 Leon Ofman , Tongjiang Wang , Joseph M. Davila

Recent observations from Parker Solar Probe have revealed that the solar wind has a highly variable structure. How this complex behaviour is formed in the solar corona is not yet known, since it requires omnipresent fluctuations, which…

From Doppler velocity maps of active regions constructed from spectra obtained by the Extreme-ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft we observe large areas of outflow (20-50 km/s) that can persist for at least a…

Astrophysics · Physics 2009-11-13 G. A. Doschek , H. P. Warren , J. T. Mariska , K. Muglach , J. L. Culhane , H. Hara , T Watanabe

The "middle corona" is a critical transition between the highly disparate physical regimes of the lower and outer solar corona. Nonetheless, it remains poorly understood due to the difficulty of observing this faint region (1.5-3 solar…

Hinode's EUV Imaging Spectrometer (EIS) has discovered ubiquitous outflows of a few to 50 km/sec from active regions (ARs). These outflows are most prominent at the AR boundary and appear over monopolar magnetic areas. They are linked to…

Solar and Stellar Astrophysics · Physics 2014-11-20 D. Baker , L. van Driel-Gesztelyi , C. H. Mandrini , P. Demoulin , M. J. Murray

Propagating disturbances are often observed in active region fan-like coronal loops. They were thought to be due to slow mode MHD waves based on some of the observed properties. But the recent studies involving spectroscopy indicate that…

Solar and Stellar Astrophysics · Physics 2015-11-11 S. Mandal , T. Samanta , D. Banerjee , S. Krishna Prasad , L. Teriaca

Context: Solar active regions (ARs) are key manifestations of the Sun's magnetic activity, displaying diverse spatial and temporal characteristics. Their formation and evolution play a crucial role in understanding the solar dynamo and…

Solar and Stellar Astrophysics · Physics 2025-08-06 M. Švanda , J. Jurčák , M. Schmassmann

The element abundances in the solar corona and solar wind are often different from those of the solar photosphere, typically with a relative enrichment of elements with low first ionization potential (FIP effect). Here we study the spatial…

Solar and Stellar Astrophysics · Physics 2023-02-22 Paola Testa , Juan Martinez-Sykora , Bart De Pontieu

Ubiquitous small-scale vortices have recently been found in the lower atmosphere of the quiet Sun in state-of-the-art solar observations and in numerical simulations. We investigate the characteristics and temporal evolution of a…

Solar and Stellar Astrophysics · Physics 2016-01-27 S. -H. Park , G. Tsiropoula , I. Kontogiannis , K. Tziotziou , E. Scullion , J. G. Doyle

Context. Several physical properties of solar polar plumes have been identified by different published studies, however such studies are rare and sometimes in disagreement. Aims. The purpose of the present work is to analyze a set of…

Solar and Stellar Astrophysics · Physics 2020-11-18 L. Zangrilli , S. M. Giordano

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

Spectroscopic observations with the EUV Imaging Spectrometer (EIS) on Hinode have revealed large areas of high speed outflows at the periphery of many solar active regions. These outflows are of interest because they may connect to the…

Solar and Stellar Astrophysics · Physics 2015-05-19 Harry P. Warren , Ignacio Ugarte-Urra , Peter R. Young , Guillermo Stenborg

High resolution spectra from the Hinode EUV Imaging Spectrometer (EIS) have revealed that coronal spectral line profiles are sometimes asymmetric, with a faint enhancement in the blue wing on the order of 100 km/s. These asymmetries could…

Solar and Stellar Astrophysics · Physics 2015-06-11 David H. Brooks , Harry P. Warren

Downflows with high velocities occur in the transition region above many sunspots; however, how these signatures evolve over short time-scales in both spatial and spectral terms is still unknown. In this article, we investigate the…

Solar and Stellar Astrophysics · Physics 2020-08-26 C. J. Nelson , S. Krishna Prasad , M. Mathioudakis

Universal small-scale solar activity in quiet region are suggested to be a potential source of solar wind and the upper solar atmosphere. Here, with the high-resoltion 174 \AA~imaging observations from the Solar Orbiter/Extreme Ultraviolet…

Solar and Stellar Astrophysics · Physics 2024-12-19 Yadan Duan , Hechao Chen , Zhenyong Hou , Zheng Sun , Yuandeng Shen

Solar active regions are associated with Evershed outflows in sunspot penumbrae, moat outflows surrounding sunspots, and extended inflows surrounding active regions. The latter have been identified on established active regions by various…

Solar and Stellar Astrophysics · Physics 2021-09-01 N. Gottschling , H. Schunker , A. C. Birch , B. Löptien , L. Gizon

Using high-resolution ring analysis (HRRA) we deduce subsurface flows within magnetic active regions and within quiet sun. With this procedure we are capable of measuring flows with a horizontal spatial resolution of 2 degrees in…

Solar and Stellar Astrophysics · Physics 2011-02-11 Bradley W. Hindman , Deborah A. Haber , Juri Toomre

The profiles of emission lines formed in the corona contain information on the dynamics and the heating of the hot plasma. Only recently has data with sufficiently high spectral resolution become available for investigating the details of…

Solar and Stellar Astrophysics · Physics 2015-05-18 H. Peter

Spectroscopic observations at extreme and far ultraviolet wavelengths have revealed systematic upflows in the solar transition region and corona. These upflows are best seen in the network structures of the quiet Sun and coronal holes,…

Solar and Stellar Astrophysics · Physics 2021-03-17 Hui Tian , Louise Harra , Deborah Baker , David H. Brooks , Lidong Xia