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Related papers: Hysteresis in a Solar Activity Cycle

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In this work, we perform a statistical study of magnetic field fluctuations in the solar wind at 1 au using permutation entropy and complexity analysis, and the investigation of the temporal variations of the Hurst exponents. Slow and fast…

Solar and Stellar Astrophysics · Physics 2024-03-26 Emilia Kilpua , Simon Good , Matti Ala-Lahti , Adnane Osmane , Venla Koikkalainen

Using wavelet analysis approach, we can derive a measure of the disorder content of solar activity, following the temporal evolution of the so-called wavelet entropy. The interesting feature of this parameter is its ability to extract a…

Astrophysics · Physics 2015-06-24 Stefano Sello

We present an analysis of solar wind dynamics based on Doppler spectral width measurements of X-band radio signals from the Japanese Akatsuki spacecraft. The dataset includes two solar conjunction occultation experiments conducted in 2016…

Solar and Stellar Astrophysics · Physics 2025-08-11 Keshav Aggarwal , R. K. Choudhary , Abhirup Datta , Takeshi Imamura

In the present work we utilize ACE/SWICS in-situ measurements of the properties of the solar wind outside ICMEs in order to determine whether, and to what extent are the solar wind properties affected by the solar cycle. We focus on proton…

Solar and Stellar Astrophysics · Physics 2022-01-17 A. Cardenas-O'Toole , E. Landi

On the basis of morphological analysis of yearly values of the maximum CME (coronal mass ejection) speed index, the sunspot number and total sunspot area, sunspot magnetic field, and solar flare index, the solar wind speed and…

Solar and Stellar Astrophysics · Physics 2016-06-22 A. Özgüç , A. Kilcik , K. Georgieva , B. Kirov

We analyzed intermittency in the solar wind, as observed on the ecliptic plane, looking at magnetic field and velocity fluctuations between 0.3 and 1 AU, for both fast and slow wind and for compressive and directional fluctuations. Our…

Astrophysics · Physics 2015-06-24 R. Bruno , V. Carbone , L. Sorriso-Valvo , B. Bavassano

We analyze time series data of the fluctuations of slow solar wind velocity using rank order statistics. We selected a total of 18 datasets measured by the Helios spacecraft at a distance of 0.32 AU from the sun in the inner heliosphere.…

Solar and Stellar Astrophysics · Physics 2011-12-23 Vinita Suyal , Awadhesh Prasad , Harinder P. Singh

Studies of solar wind turbulence traditionally employ high-resolution magnetic field data, but high-resolution measurements of ion and electron moments have been possible only recently. We report the first turbulence studies of ion and…

Using intermediate degree p mode frequency data sets for solar cycle 22, we find that the frequency shifts and magnetic indices show a `hysteresis' phenomenon. It is observed that the magnetic indices follow different paths for the…

Astrophysics · Physics 2015-06-24 S. C. Tripathy , Brajesh Kumar , Kiran Jain , A. Bhatnagar

Current-voltage measurements are a standard testing protocol to determine the efficiency of any solar cell. However, perovskite solar cells display significant kinetic phenomena that modify the performance at several time scales, due to…

Applied Physics · Physics 2024-07-03 Enrique H. Balaguera , Juan Bisquert

The solar activity in the current, that is, the 24-th, sunspot cycle is analyzed. Cyclic variations in the sunspot number (SSN) and radiation fluxes in various spectral ranges have been estimated in comparison with the general level of the…

Solar and Stellar Astrophysics · Physics 2018-05-01 E. A. Bruevich , V. V. Bruevich , G. V. Yakunina

This research provides an analysis of extreme events in the solar wind and in the magnetosphere due to disturbances of the solar wind. Extreme value theory has been applied to a 20 year data set from the Advanced Composition Explorer (ACE)…

Space Physics · Physics 2021-12-02 C. Larrodera , L. Nikitina , C. Cid

A well-known property of solar wind plasma turbulence is the observed anisotropy of the autocorrelations, or equivalently the spectra, of velocity and magnetic field fluctuations. Here we explore the related but apparently not well-studied…

To investigate the power and spectral index anisotropy in the inertial range of solar wind turbulence, we use 70 intervals of electric field data accumulated by Cluster spacecraft in the free solar wind. We compute the electric field…

Space Physics · Physics 2020-09-24 Deepali , Supratik Banerjee

We investigate Venus Express (VEX) observations of magnetic field fluctuations performed systematically in the solar wind at 0.72 Astronomical Units (AU), between 2007 and 2009, during the deep minimum of the solar cycle 24. The Power…

The ratio of the rms electron density fluctuations to the background density in the solar wind (density modulation index, $\epsilon_{N} \equiv \Delta{N}/N$) is of vital importance in understanding several problems in heliospheric physics…

Solar and Stellar Astrophysics · Physics 2015-06-22 Susanta Kumar Bisoi , P. Janardhan , M. Ingale , P. Subramanian , S. Ananthakrishnan , M. Tokumaru , K. Fujiki

This paper presents the analysis of 3D evolution of solar wind density turbulence and speed at various levels of solar activity between solar cycles 22 and 24. The solar wind data has been obtained from interplanetary scintillation (IPS)…

Solar and Stellar Astrophysics · Physics 2015-06-04 P. K. Manoharan

In this paper we use statistical complexity and information theory metrics to study structure within solar wind time series. We explore this using entropy-complexity and information planes, where the measure for entropy is formed using…

Solar and Stellar Astrophysics · Physics 2025-10-08 Venla Koikkalainen , Emilia Kilpua , Simon Good , Adnane Osmane

An evolving turbulent flow such as the solar wind can be meaningfully characterized by its "turbulence age" -- an estimate of the number of nonlinear times that have elapsed during a plasma parcel's propagation from the Sun to a given point…

Solar and Stellar Astrophysics · Physics 2026-03-30 Rohit Chhiber , Yanwen Wang , Arcadi V. Usmanov , William H. Matthaeus

We present the first survey of electric field data using the ARTEMIS spacecraft in the solar wind to study inertial range turbulence. It was found that the average perpendicular spectral index of the electric field depends on the frame of…

Space Physics · Physics 2012-08-20 C. H. K. Chen , S. D. Bale , C. Salem , F. S. Mozer
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