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

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A statistical relationship between magnetic reconnection, current sheets and intermittent turbulence in the solar wind is reported for the first time using in-situ measurements from the Wind spacecraft at 1 AU. We identify intermittency as…

Space Physics · Physics 2015-06-19 K. T. Osman , W. H. Matthaeus , J. T. Gosling , A. Greco , S. Servidio , B. Hnat , S. C. Chapman , T. D. Phan

Orthogonal wavelet transforms are a cornerstone of modern signal and image denoising because they combine multiscale representation, energy preservation, and perfect reconstruction. In this paper, we show that these advantages can be…

Computation · Statistics 2026-03-04 Radhika Kulkarni , Brani Vidakovic

Solar radiation prediction is an important challenge for the electrical engineer because it is used to estimate the power developed by commercial photovoltaic modules. This paper deals with the problem of solar radiation prediction based on…

Neural and Evolutionary Computing · Computer Science 2013-08-19 Giacomo Capizzi , Christian Napoli , Francesco Bonanno

This article consists of a brief discussion of the energy density over time or frequency that is obtained with the wavelet transform. Also an efficient algorithm is suggested to calculate the continuous transform with the Morlet wavelet.…

Data Analysis, Statistics and Probability · Physics 2011-11-10 Richard Buessow

The recently released spacecraft potential measured by the RPW instrument on-board Solar Orbiter has been used to estimate the solar wind electron density in the inner heliosphere. Solar-wind electron density measured during June 2020 has…

The magnetic field of a sunspot guides magnetohydrodynamic waves toward higher atmospheric layers. In the upper photosphere and lower chromosphere, wave modes with periods longer than the acoustic cut-off period become evanescent. The…

Solar and Stellar Astrophysics · Physics 2016-12-07 J. Löhner-Böttcher , N. Bello González , W. Schmidt

This paper uses wavelet transforms to look for the rotational frequencies of the Sun's mean line-of-sight magnetic field. For a sufficiently high wavelet frequency, the spectra of the dipole, quadrupole, and hexapole field components each…

Solar and Stellar Astrophysics · Physics 2023-10-27 Neil R. Sheeley

It is shown that, the wavelet regression detrended fluctuations of the monthly sunspot number for 1749-2009 years exhibit strong periodicity with a period approximately equal to 3.7 years. The wavelet regression method detrends the data…

Solar and Stellar Astrophysics · Physics 2011-01-14 A. Bershadskii

We study time evolution of the relationship between sunspot numbers and global temperatures between 1880 and 2016 using wavelet coherence framework. The results suggest that the relationship is stable in time. Changes in the sunspot numbers…

Applications · Statistics 2018-10-30 Ladislav Kristoufek

We explore subtle variations in disk-integrated measurements spanning $\lsim$ 18 years of stellar surface magnetism by using a newly developed time-frequency gapped wavelet algorithm. We present results based on analysis of the Mount Wilson…

Astrophysics · Physics 2016-08-30 Willie Soon , Peter Frick , Sallie Baliunas

The continuous wavelet transform has become a widely used tool in applied science during the last decade. In this article we discuss some generalizations coming from actions of closed subgroups of $\mathrm{GL}(n,\mathbb{R})$ acting on…

Functional Analysis · Mathematics 2007-05-23 R. Fabec , G. Olafsson

The wavelet transform has been used for numerous studies in astrophysics, including signal--noise periodicity and decomposition as well as the signature of differential rotation in stellar light curves. In the present work, we apply the…

Solar and Stellar Astrophysics · Physics 2010-09-28 D. B. de Freitas , I. de C. Leão , B. L. Canto Martins , J. R. De Medeiros

It is generally believed that sunspots are the emergent part of magnetic flux tubes in the solar interior. These tubes are created at the base of the convection zone and rise to the surface due to their magnetic buoyancy. The motion of…

Solar and Stellar Astrophysics · Physics 2015-05-14 Franck Plunian , Graeme Sarson , Rodion Stepanov

The underlying mathematics of the wavelet formalism is a representation of the inhomogeneous Lorentz group or the affine group. Within the framework of wavelets, it is possible to define the ``window'' which allows us to introduce a…

Quantum Physics · Physics 2007-05-23 Y. S. Kim

We present a new method for computing the wave function in the presence of constraints. As an explicit example we compute the wave function for the many electrons problem in coupled metallic rings in the presence of external magnetic…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 D. Schmeltzer

Sunspots are dark spots on the solar surface associated with strong magnetic fields. The number, area, and brightness of sunspots are supposed to reflect the intensity of the solar magnetic fields and are often used as proxies for their…

Solar and Stellar Astrophysics · Physics 2015-06-16 K. Georgieva , B. Kirov , Yu. A. Nagovitsyn

In this paper, we exploit the theory of convolution of index Whittaker transform for study of continuous and discrete Index Whittaker wavelet transform and discuss some of its basic properties. Certain boundedness, Plancherel as well as…

Functional Analysis · Mathematics 2019-08-19 Ashish Pathak , Abhishek

Magnetic field modifies the properties of waves in a complex way. Significant advances has been made recently in our understanding of the physics of waves in solar active regions with the help of analytical theories, numerical simulations,…

Astrophysics · Physics 2008-12-02 Elena Khomenko

We show that the cone-adapted shearlet coefficients can be computed by means of the limited angle horizontal and vertical (affine) Radon transforms and the one-dimensional wavelet transform. This yields formulas that open new perspectives…

Functional Analysis · Mathematics 2019-10-24 Francesca Bartolucci , Filippo De Mari , Ernesto De Vito

The correlation scale and the Taylor scale are evaluated for interplanetary magnetic field fluctuations from two-point, single time correlation function using the Advanced Composition Explorer (ACE), Wind, and Cluster spacecraft data during…

Space Physics · Physics 2020-08-20 G. Zhou , H. -Q. He , W. Wan