English
Related papers

Related papers: Wavelets and Solar Magnetic Activity I: Wavelets o…

200 papers

The Sun exhibits episodic surges of magnetic activity across a range of temporal and spatial scales, the most prominent of which is the 11-ish year modulation of sunspot production. Beside the ~170 (min to max) decadal variation in sunspot…

Solar and Stellar Astrophysics · Physics 2024-08-21 Scott W. McIntosh , Robert J. Leamon

Wavelet basis functions are a natural tool for analyzing turbulent flows containing localized coherent structures of different spatial scales. Here, wavelets are used to study the onset and subsequent transition to fully developed…

Plasma Physics · Physics 2022-04-13 Ari Le , Vadim Roytershteyn , Homa Karimabadi , Adam Stanier , Luis Chacon , Kai Schneider

Wavelet Transforms are a widely used technique for decomposing a signal into coefficient vectors that correspond to distinct frequency/scale bands while retaining time localization. This property enables an adaptive analysis of signals at…

Applications · Statistics 2025-11-05 Jack Kissell , Vijini Lakmini , Brani Vidakovic

Wind turbines operate in the atmospheric boundary layer, where they are exposed to the turbulent atmospheric flows. As the response time of wind turbine is typically in the range of seconds, they are affected by the small scale intermittent…

The structure of the surface layers of the Sun is changed by magnetic activity which, in turn, changes the eigenfrequencies of the acoustic modes. These frequency shifts have been observed both in low- and high-degree data, and are found to…

Astrophysics · Physics 2007-05-23 M. Cunha , M. Bruggen , D. O. Gough

We derive formulae connecting the frequency variations in the spectrum of solar oscillations to the dynamical quantities that are expected to change over the solar activity cycle. This is done for both centroids and the asymmetric part of…

Astrophysics · Physics 2009-11-10 W. A. Dziembowski , P. R. Goode

Rotation is a significant characteristic of the Sun and other stars, and it plays an important role in understanding their dynamo actions and magnetic activities. In this study, the rotation of the solar chromospheric activity is…

Solar and Stellar Astrophysics · Physics 2020-10-22 Jing-Chen Xu , Peng-Xin Gao , Xiang-Jun Shi

In this paper, we analyze the probability density function (PDF) of solar wind velocity and proton density, based on generalized thermostatistics (GT) approach, comparing theoretical results with observational data. The time series analyzed…

Wind Energy is a useful resource for Renewable energy purpose. Wind speed plays a vital role for wind energy calculation of certain location. So, it is very much necessary to know the wind speed data characteristics. In this paper fourier…

Computational Engineering, Finance, and Science · Computer Science 2014-08-07 Sabyasachi Mukhopadhyay , Debadatta Dash , Asish Mitra , Paritosh Bhattacharya

The transfer of a star's angular momentum to its atmosphere is a topic of considerable and wide-ranging interest in astrophysics. This letter considers the effect of kinetic and magnetic turbulence on the solar wind's angular momentum. The…

Solar and Stellar Astrophysics · Physics 2025-05-07 Rohit Chhiber , Arcadi Usmanov , William H. Matthaeus , Francesco Pecora

Wavelets are waveform functions that describe transient and unstable variations, such as noises. In this work, we study the advantages of discrete and continuous wavelet transforms (DWT and CWT) of microlensing data to denoise them and…

Instrumentation and Methods for Astrophysics · Physics 2023-10-06 Sedighe Sajadian , Hossein Fatheddin

The total solar irradiance (TSI) varies on timescales of minute to centuries. On short timescales it varies due to the superposition of intensity fluctuations produced by turbulent convection and acoustic oscillations. On longer scale…

Solar and Stellar Astrophysics · Physics 2022-10-12 V. Penza , F. Berrilli , L. Bertello , M. Cantoresi , S. Criscuoli , P. Giobbi

We introduce a new wavelet transform suitable for analyzing functions on point clouds and graphs. Our construction is based on a generalization of the average interpolating refinement scheme of Donoho. The most important ingredient of the…

Functional Analysis · Mathematics 2015-03-19 Raif M. Rustamov

The formation of shocks within the solar atmosphere remains one of the few observable signatures of energy dissipation arising from the plethora of magnetohydrodynamic waves generated close to the solar surface. Active region observations…

It is widely reported that the power spectra of magnetic field and velocity fluctuations in the solar wind have power law scalings with inertial-range spectral indices of -5/3 and -3/2 respectively. Studies of solar wind turbulence have…

Solar and Stellar Astrophysics · Physics 2018-09-26 Trevor A. Bowen , Alfred Mallet , John W. Bonnell , Stuart D. Bale

A wavelet is a localized function having a prescribed number of vanishing moments. In this correspondence, we provide precise arguments as to why the Hilbert transform of a wavelet is again a wavelet. In particular, we provide sharp…

Functional Analysis · Mathematics 2013-07-23 Kunal Narayan Chaudhury , Michael Unser

We present in this paper new multiscale transforms on the sphere, namely the isotropic undecimated wavelet transform, the pyramidal wavelet transform, the ridgelet transform and the curvelet transform. All of these transforms can be…

Astrophysics · Physics 2016-08-30 Jean-Luc Starck , Yassir Moudden , Pierrick Abrial , Mai Nguyen

Finding a computationally efficient algorithm for the inverse continuous wavelet transform is a fundamental topic in applications. In this paper, we show the convergence of the inverse wavelet transform.

Functional Analysis · Mathematics 2010-09-01 Wenchang Sun

A direct numerical simulation of an oblique shock wave impinging on a turbulent boundary layer at Mach number 2.28 is carried out at moderate Reynolds number, simulating flow conditions similar to those of the experiment by Dupont et al.…

Fluid Dynamics · Physics 2023-01-25 Matteo Bernardini , Giacomo Della Posta , Francesco Salvadore , Emanuele Martelli

The Sun is the main energy source to Earth, and understanding its variability is of direct relevance to climate studies. Measurements of total solar irradiance exist since 1978, but this is too short compared to climate-relevant time…

Solar and Stellar Astrophysics · Physics 2023-10-17 Theodosios Chatzistergos , Natalie A. Krivova , Kok Leng Yeo