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Related papers: Multifractal Solar EUV Intensity Fluctuations and …

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In this study we combine the multiwavelength ultraviolet -- optical (Solar Dynamics Observatory, SDO) and radio (Nobeyama Radioheliograph, NoRH) observations to get further insight into space-frequency distribution of oscillations at…

Solar and Stellar Astrophysics · Physics 2015-05-13 D. Y. Kolobov , N. I. Kobanov , A. A. Chelpanov , A. A. Kochanov , S. A. Anfinogentov , S. A. Chupin , I. I. Myshyakov , V. E. Tomin

This paper presents a study of a large sample of global disturbances in the solar corona with characteristic propagating fronts as intensity enhancement, similar to the phenomena that have often been referred to as EIT waves or EUV waves.…

Solar and Stellar Astrophysics · Physics 2015-06-16 Nariaki V. Nitta , Carolus J. Schrijver , Alan M. Title , Wei Liu

In addition to a component of the emission that originates from clearly distinguishable coronal loops, the solar corona also exhibits extreme-ultraviolet (EUV) and X-ray ambient emission that is rather diffuse and is often considered…

Solar and Stellar Astrophysics · Physics 2023-03-24 Nikolina Milanović , Lakshmi Pradeep Chitta , Hardi Peter

EUV imaging observations from several space missions (SOHO/EIT, TRACE, and SDO/AIA) have revealed a presence of propagating intensity disturbances in solar coronal loops. These disturbances are typically interpreted as slow magnetoacoustic…

Solar and Stellar Astrophysics · Physics 2018-01-24 Elena Provornikova , Leon Ofman , Tongjiang Wang

In this work, we have studied the temporal evolution of some properties of a sample of superactive regions with the aim to single out the most significant for flare activity forecasting. We have investigated properties of 14 superactive…

Solar and Stellar Astrophysics · Physics 2015-05-14 S. Criscuoli , P. Romano , F. Zuccarello , F. Giorgi

Solar corona is much hotter than lower layers of the solar atmosphere-photosphere and chromosphere. The coronal temperature is up to 1MK in quiet sun areas, while up to several MK in active regions, which implies a key role of magnetic…

Solar and Stellar Astrophysics · Physics 2025-06-24 Gregory D. Fleishman , Alexey A. Kuznetsov , Gelu M. Nita

The solar corona has been revealed in the past decade to be a highly dynamic nonequilibrium plasma environment. Both the loop-filled coronal base and the extended acceleration region of the solar wind appear to be strongly turbulent, but…

Astrophysics · Physics 2008-11-26 Steven R. Cranmer

Plasma turbulence cascading from MHD to kinetic scales in the heliospheric plasma is believed to play a key role in coronal heating and fast solar wind acceleration, but the properties of the turbulence remain poorly constrained by…

Solar and Stellar Astrophysics · Physics 2026-02-03 Eduard P. Kontar , A. Gordon Emslie , Daniel L. Clarkson , Alexander Pitna

The quiet solar corona consists of myriads of loop-like features, with magnetic fields originating from network and internetwork regions on the solar surface. The continuous interaction between these different magnetic patches leads to…

Solar and Stellar Astrophysics · Physics 2021-04-13 L. P. Chitta , H. Peter , P. R. Young

We investigate the decayless regime of coronal kink oscillations recently discovered in the Solar Dynamics Observatory (SDO)/AIA data. In contrast to decaying kink oscillations that are excited by impulsive dynamical processes, this type of…

Solar and Stellar Astrophysics · Physics 2015-11-18 S. A. Anfinogentov , V. M. Nakariakov , G. Nisticò

The solar corona is much hotter than the photosphere and chromosphere, but the physical mechanism responsible for heating the coronal plasma remains unidentified yet. The thermal microwave emission, which is produced in strong magnetic…

Solar and Stellar Astrophysics · Physics 2025-08-27 Alexey A. Kuznetsov , Gregory D. Fleishman , Gelu M. Nita , Sergey A. Anfinogentov

Three-minute oscillations over sunspot's umbra in AR 11131 were observed simultaneously in UV/EUV emission by SDO/AIA and in radio emission by Nobeyama Radioheliograph (NoRH). We use 24-hours series of SDO and 8-hours series of NoRH…

Solar and Stellar Astrophysics · Physics 2015-05-30 V. E. Reznikova , K. Shibasaki , R. A. Sych , V. M. Nakariakov

Previous solar observations have shown that coronal loops near 1 MK are difficult to reconcile with simple heating models. These loops have lifetimes that are long relative to a radiative cooling time, suggesting quasi-steady heating. The…

Waves are thought to play a significant role in the heating of the solar atmosphere and the acceleration of the wind. Among the many types of waves observed in the Sun, the so-called p-modes with a 3 mHz frequency peak dominate the lower…

We have measured the root-mean-square (RMS) amplitude of intensity fluctuations, $\Delta I$, in plume and interplume regions of a polar coronal hole. These intensity fluctuations correspond to density fluctuations. Using data from the…

Solar and Stellar Astrophysics · Physics 2018-06-27 Michael Hahn , Elke D'Huys , Daniel Wolf Savin

Extracting the temperature of coronal loops is effective in the analysis of solar active region's loops and helps in better understanding of coronal events. To this end, various methods have already been developed like the method developed…

Solar and Stellar Astrophysics · Physics 2019-08-30 Narges Fathalian

We investigate the properties and relationship between Doppler-velocity fluctuations and intensity fluctuations in the off-limb quiet Sun corona. These are expected to reflect the properties of Alfvenic and compressive waves, respectively.…

Solar and Stellar Astrophysics · Physics 2025-03-21 Michael Hahn , Xiangrong Fu , Stefan J. Hofmeister , Yifan Huang , Alexandros Koukras , Daniel Wolf Savin

The present solar cycle is particular in many aspects: it had a delayed rising phase, it is the weakest of the last 100 years, and it presents two peaks separated by more than one year. To understand the impact of these characteristics on…

Solar and Stellar Astrophysics · Physics 2017-11-08 A. J. Oliveira e Silva , C. L. Selhorst , P. J. A. Simões , C. G. Giménes de Castro

Coronal flare emission is commonly observed to decay on timescales longer than those predicted by impulsively-driven, one-dimensional flare loop models. This discrepancy is most apparent during the gradual phase, where emission from these…

Solar and Stellar Astrophysics · Physics 2023-03-01 William Ashfield , Dana Longcope

We present the multifractal study of the intermittency of the magnetic field turbulence in the fast and slow solar wind beyond the ecliptic plane during two solar minima (1997-1998, 2007-2008) and solar maximum (1999-2001). More precisely,…

Space Physics · Physics 2019-05-23 Anna Wawrzaszek , Marius Echim , Roberto Bruno