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Related papers: Solar Flare 1/f Fluctuations from Amplitude Modula…

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We first report that the seismic time-sequence data from around the world, excluding major earthquakes, consistently yield the power spectral density inversely proportional to the frequency f. This is the 1/f fluctuation that appears…

Geophysics · Physics 2023-12-19 Akika Nakamichi , Manaya Matsui , Masahiro Morikawa

Fluctuations and structure across a wide range of spatial and temporal scales are frequently studied in the solar wind. The properties of the low-frequency fluctuations are of relevance to turbulent energy injection into the plasma and the…

Solar and Stellar Astrophysics · Physics 2026-01-06 Jiaming Wang , Francesco Pecora , Rohit Chhiber , Sohom Roy , William H. Matthaeus

The power spectrum of the evolving solar wind shows evidence of a spectral break between an inertial range of turbulent fluctuations at higher frequencies and a "$1/f$" like region at lower frequencies. In the ecliptic plane at $\sim 1$ AU,…

Solar and Stellar Astrophysics · Physics 2009-09-24 R. M. Nicol , S. C. Chapman , R. O. Dendy

The $1/f$ noise is a ubiquitous phenomenon in natural systems. Since the advent of space exploration, the $1/f$ range has been consistently observed in \textit{in situ} solar wind measurements throughout the heliosphere, sparking decades of…

Solar and Stellar Astrophysics · Physics 2025-09-03 Zesen Huang , Marco Velli , B. D. G. Chandran , Chen Shi , Yuliang Ding , Lorenzo Matteini , Kyung-Eun Choi

We discuss properties of large amplitude magnetic field fluctuations during fast Alfvenic solar wind streams, focussing on the statistics of the rotation angle between consecutive magnetic field vector measurements for different scales in…

Space Physics · Physics 2019-10-17 L. Matteini , D. Stansby , T. S. Horbury , C. H. K. Chen

We analyze space-based time series photometry of Sun-like stars, mostly in the Pleiades, but also field stars and the Sun itself. We focus on timescales between roughly 1 hour and 1 day. In the corresponding frequency band these stars…

Solar and Stellar Astrophysics · Physics 2021-08-06 Timothy M. Brown , Rafael A. Garcia , Savita Mathur , Travis S. Metcalfe , Angela R. G. Santos

We discuss properties of Alfv\'enic fluctuations with large amplitude in plasmas characterised by low magnetic field compression. We note that in such systems power laws can not develop with arbitrarily steep slopes at large scales, i.e.…

Space Physics · Physics 2018-12-26 Lorenzo Matteini , David Stansby , Timothy Horbury , Christopher H. K. Chen

Context. Solar activity cycles vary in amplitude and duration. The variations can be at least partly explained by fluctuations in dynamo parameters. Aims. We want to restrict uncertainty in fluctuating dynamo parameters and find out which…

Solar and Stellar Astrophysics · Physics 2018-07-18 L. L. Kitchatinov , A. V. Mordvinov , A. A. Nepomnyashchikh

We investigate consecutive absorption or emission of photons of the quantum mechanical harmonic oscillator as a possible source of 1/f fluctuations. Separating the absorption and emission process, we show that consecutively absorbed or…

Data Analysis, Statistics and Probability · Physics 2012-05-31 Ferdinand Grueneis

The underlying physics that generates the excitations in the global low-frequency, < 5.3 mHz, solar acoustic power spectrum is a well known process that is attributed to solar convection; However, a definitive explanation as to what causes…

Solar and Stellar Astrophysics · Physics 2015-06-05 M. Richardson , F. Hill , K. G. Stassun

The fast solar wind shows a wide spectrum of transverse magnetic and velocity field perturbations. These perturbations are strongly correlated in the sense of Alfv\'en waves propagating mostly outward, from the Sun to the interplanetary…

Solar and Stellar Astrophysics · Physics 2023-04-12 Réville Victor , Tenerani Anna , Velli Marco

Fluctuations of solar wind magnetic field and plasma parameters exhibit a typical turbulence power spectrum with a spectral index ranging between $\sim -5/3$ and $\sim -3/2$. In particular, at $1$ AU, the magnetic field spectrum, observed…

Space Physics · Physics 2019-07-10 R. Bruno , D. Telloni , L. Sorriso-Valvo , R. Marino , R. De Marco , R. DAmicis

Solar wind fluctuations, such as magnetic field or velocity, show power law power spectra suggestive both of an inertial range of intermittent turbulence (with $\sim -5/3$ exponent) and at lower frequencies, of fluctuations of coronal…

Astrophysics · Physics 2009-11-13 R. M. Nicol , S. C. Chapman , R. O. Dendy

We have evaluated fluctuations in neutrino fluxes caused by solar gravity (g) modes based on the analysis of linear adiabatic oscillation of a spherically symmetric star. We find that the first-order fluctuation is zero due to geometrical…

Solar and Stellar Astrophysics · Physics 2026-04-09 Yoshiki Hatta , Yuuki Nakano , Sho Sugama , Masanobu Kunitomo , Hiroshi Ito , Takashi Sekii

Alfv\'enic fluctuations are very common features in the solar wind and are found especially within the main portion of fast wind streams while the slow wind usually is less Alfv\'enic and more variable. In general, fast and slow wind show…

Space Physics · Physics 2018-12-19 Raffaella D'Amicis , Lorenzo Matteini , Roberto Bruno

Recently, many superflares on solar-type stars were discovered as white-light flares (WLFs). A correlation between the energies (E) and durations (t) of superflares is derived as $t\propto E^{0.39}$, and this can be theoretically explained…

Rapid fluctuation with a frequency dependence of $1/f^{\alpha}$ (with $\alpha \simeq 1 - 2$) is characteristic of radiation from black-hole objects. Its origin remains poorly understood. We examine the three-dimensional…

Astrophysics · Physics 2015-06-24 T. Kawaguchi , S. Mineshige , M. Machida , R. Matsumoto , K. Shibata

The trace magnetic power spectrum in the solar wind is known to be characterized by a double power law at scales much larger than the proton gyro-radius, with flatter spectral exponents close to -1 found at the lower frequencies below an…

The interplanetary magnetic field exhibits a distinctive $1/f$ spectral density from frequencies of around $\unit[10^{-6}]{Hz}$ to around $\unit[10^{-4}]{Hz}$, ranging from harmonics of the solar rotation to the reciprocal of the turbulence…

The power spectrum of magnetic-field fluctuations in the fast solar wind ($V_{\rm SW}> 500 \mbox{ km} \mbox{ s}^{-1}$) at magnetohydrodynamic (MHD) scales is characterized by two different power laws on either side of a break frequency…

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