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Related papers: Solar cycle dependence of spatial correlation in t…

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We use dual-site radio observations of interplanetary scintillation (IPS) with extremely long baselines (ELB) to examine meridional flow characteristics of the ambient fast solar wind at plane-of-sky heliocentric distances of 24-85 solar…

Solar and Stellar Astrophysics · Physics 2015-06-05 Gareth Dorrian , Andy Breen , Richard Fallows , Mario Bisi

Solar wind magnetic fluctuations exhibit anisotropy due to the presence of a mean magnetic field in the form of the Parker spiral. Close to the Sun, direct measurements were not available until the recently launched Parker Solar Probe (PSP)…

Solar and Stellar Astrophysics · Physics 2022-01-05 Riddhi Bandyopadhyay , David J. McComas

We considered variations the dipole and the quadrupole components of the solar large-scale magnetic field. Both the axial and the equatorial dipoles exhibit a systematic decrease in the past four cycles in accordance with the general…

Solar and Stellar Astrophysics · Physics 2020-02-19 V. N. Obridko , D. D. Sokoloff , B. D. Shelting , A. S. Shibalova , I. M. Livshits

We study the relationship between solar wind helium to hydrogen abundance ratio ($A_\mathrm{He}$), solar wind speed ($v_\mathrm{SW}$), and sunspot number (SSN) over solar cycles 23 and 24. This is the first full 22-year Hale cycle measured…

Space Physics · Physics 2019-07-01 B. L. Alterman , Justin C. Kasper

We extend a two-component model for the evolution of fluctuations in the solar wind plasma so that it is fully three-dimensional (3D) and also coupled self-consistently to the large-scale magnetohydrodynamic (MHD) equations describing the…

Solar and Stellar Astrophysics · Physics 2016-12-14 Tobias Wiengarten , Sean Oughton , Eugene Engelbrecht , Horst Fichtner , Jens Kleimann , Klaus Scherer

We investigate the nature of magnetic turbulent fluctuations, around ion characteristic scales, in a fast solar wind stream, by using {\it Cluster} data. Contrarily to slow solar wind, where both Alfv\'enic ($\delta b_{\perp} \gg \delta…

Plasma Physics · Physics 2017-11-08 D. Perrone , O. Alexandrova , O. W. Roberts , S. Lion , C. Lacombe , A. Walsh , M. Maksimovic , I. Zouganelis

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 analysed the recently available GONG p-mode frequencies and splitting coefficients for a period of three and half years, including the rapidly rising phase of solar cycle 23. The analysis of mean frequency shift with different…

Astrophysics · Physics 2009-10-31 Kiran Jain , S. C. Tripathy , A. Bhatnagar

The Earth's magnetosphere extension is controlled by the solar activity level via solar wind properties. Understanding such a relation in the Solar System is important for predicting also the condition of exoplanetary magnetospheres near…

Using a nonlinear mean-field solar dynamo model, we study relationships between the amplitude of the `extended' mode of migrating zonal flows (`torsional oscillations') and magnetic cycles, and investigate whether properties the torsional…

Solar and Stellar Astrophysics · Physics 2020-09-02 V. V. Pipin , A. G. Kosovichev

The structure of electric current and magnetic helicity in the solar corona is closely linked to solar activity over the 11-year cycle, yet is poorly understood. As an alternative to traditional current-free "potential field"…

Solar and Stellar Astrophysics · Physics 2015-05-18 A. R. Yeates , J. A. Constable , P. C. H. Martens

We update the best constraints on fluctuations in the solar medium deep within the solar Radiative Zone to include the new SNO-salt solar neutrino measurements. We find that these new measurements are now sufficiently precise that neutrino…

High Energy Physics - Phenomenology · Physics 2009-09-17 C. P. Burgess , N. S. Dzhalilov , M. Maltoni , T. I. Rashba , V. B. Semikoz , M. A. Tortola , J. W. F. Valle

The scaling of magnetic fluctuations provides crucial information for the understanding of solar wind turbulence. However, the observed magnetic fluctuations contain not only turbulence but also magnetic structures, leading to the violation…

Space Physics · Physics 2023-04-26 Honghong Wu , Jiansen He , Shiyong Huang , Liping Yang , Xin Wang , Zhigang Yuan

We study the connections between the sun's convection zone and the evolution of the solar wind and corona. We let the magnetic fields generated by a 2.5D axisymmetric kinematic dynamo code (STELEM) evolve in a 2.5D axisymmetric coronal…

Solar and Stellar Astrophysics · Physics 2015-05-28 Rui F. Pinto , Allan Sacha Brun , Laurène Jouve , Roland Grappin

We study the relationship of the 27-day variation of the galactic cosmic ray intensity with similar changes of the solar wind velocity and the interplanetary magnetic field based on the experimental data for the Bartels rotation period 2379…

Solar and Stellar Astrophysics · Physics 2015-04-06 M. V. Alania , R. Modzelewska , A. Wawrzynczak

We present independent observations of the solar-cycle variation of flows near the solar surface and at a depth of about 60 Mm, in the latitude range $\pm45^\circ$. We show that the time-varying components of the meridional flow at these…

Astrophysics · Physics 2009-11-13 L. Gizon , M. Rempel

The Sun and Sun-like stars lose angular momentum to their magnetised stellar winds. This braking torque is coupled to the stellar magnetic field, such that changes in the strength and/or geometry of the field modifies the efficiency of this…

Solar and Stellar Astrophysics · Physics 2019-10-02 Adam J. Finley , Siddhant Deshmukh , Sean P. Matt , Mathew Owens , Chi-Ju Wu

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

The solar cycle is a complex phenomenon. To comprehensively understand it, we have to study various tracers. The most important component of this complex is the solar dynamo, which is understood as self-excitation of the solar magnetic…

Solar and Stellar Astrophysics · Physics 2025-01-10 V. N. Obridko , A. S. Shibalova , D. D. Sokoloff

Incompressible Magnetohydrodynamics is often assumed to describe solar wind turbulence. We use extended self similarity to reveal scaling in structure functions of density fluctuations in the solar wind. Obtained scaling is then compared…

Astrophysics · Physics 2009-11-10 Bogdan Hnat , Sandra C. Chapman , George Rowlands