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相关论文: Scaling in long term data sets of geomagnetic indi…

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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.…

空间物理 · 物理学 2018-12-26 Lorenzo Matteini , David Stansby , Timothy Horbury , Christopher H. K. Chen

We utilize solar rotation average geomagnetic index ap and various solar wind plasma and field parameters for four solar cycles 20-23. We perform analysis to search for a best possible coupling function at 27-day time resolution. Regression…

太阳与恒星天体物理 · 物理学 2014-04-07 Badruddin , O. P. M. Aslam

The solar wind is a magnetized and turbulent plasma. Its turbulence is often dominated by Alfv\'enic fluctuations and often deemed as nearly incompressible far away from the Sun, as shown by in-situ measurements near 1AU. However, for solar…

太阳与恒星天体物理 · 物理学 2022-09-14 Xiangrong Fu , Hui Li , Zhaoming Gan , Senbei Du , John Steinberg

The anisotropy of magnetophydrodynamic turbulence is investigated by using solar wind data from the Helios 2 spacecraft. We investigate the behaviour of the complete high-order moment tensors of magnetic field increments and we compare the…

空间物理 · 物理学 2009-11-13 Luca Sorriso-Valvo , Vincenzo Carbone , Roberto Bruno , Pierluigi Veltri

Comparison is carried out of the long term variation of the year averaged solar wind speed and interplanetary scintillation index with the variations of Wolf's numbers and A_P indexes of geomagnetic activity for the data of 20-24 solar…

空间物理 · 物理学 2022-08-09 V. I. Vlasov , R. D. Dagkesamanskii , V. A. Potapov , S. A. Tyul'bashev , I. V. Chashei

We investigate whether Alfv\'enic fluctuations (AFs) can affect the structure of magnetic ejecta (MEs) within interplanetary coronal mass ejections (ICMEs). We study an ICME observed on 2001 December 29 at 1 au by ACE and Wind, at a total…

We could infer a secular decreasing trend in the poloidal to toroidal solar magnetic flux amplification factor ( Af) using geomagnetic observations ( classic and IHV corrected aa indices) during the sunspot cycles 9-23. A similar decreasing…

综合物理 · 物理学 2010-12-23 T. E. Girish , G. Gopkumar

This Letter investigates the spectral characteristics of the interplanetary magnetic field fluctuations at proton scales during several time intervals chosen along the speed profile of a fast stream. The character of the fluctuations within…

太阳与恒星天体物理 · 物理学 2015-09-30 R. Bruno , D. Telloni

We motivate the importance of studying kinetic scale turbulence for understanding the macroscopic properties of the heliosphere, such as the heating of the solar wind. We then discuss the technique by which kinetic scale density…

空间物理 · 物理学 2013-06-25 C. H. K. Chen , G. G. Howes , J. W. Bonnell , F. S. Mozer , K. G. Klein , S. D. Bale

It has long been known that the energy in velocity and magnetic field fluctuations in the solar wind is not in equipartition. In this paper, we present an analysis of 5 years of Wind data at 1 AU to investigate the reason for this. The…

空间物理 · 物理学 2013-06-10 C. H. K. Chen , S. D. Bale , C. S. Salem , B. A. Maruca

Fluctuations in the flow velocity and magnetic fields are ubiquitous in the Solar System. These fluctuations are turbulent, in the sense that they are disordered and span a broad range of scales in both space and time. The study of solar…

太阳与恒星天体物理 · 物理学 2016-02-04 F. Fraternale , L. Gallana , M. Iovieno , M. Opher , J. D. Richardson , D. Tordella

The goal of our study is to detect and characterize the electromagnetic waves that can modify the electron distribution functions, with a special attention to whistler waves. We analyse in details the electric and magnetic field…

We investigate the anisotropy of Alfv\'enic turbulence in the inertial range of slow solar wind and in both driven and decaying reduced magnetohydrodynamic simulations. A direct comparison is made by measuring the anisotropic second-order…

空间物理 · 物理学 2012-08-20 C. H. K. Chen , A. Mallet , T. A. Yousef , A. A. Schekochihin , T. S. Horbury

Parker Solar Probe (PSP) observed sub-Alfvenic solar wind intervals during encounters 8 - 14, and low-frequency magnetohydrodynamic turbulence in these regions may differ from that in super-Alfvenic wind. We apply a new mode-decomposition…

The North Atlantic Oscillation (NAO) monthly index is studied from 1825 till 2002 in order to identify the scaling ranges of its fluctuations upon different delay times and to find out whether or not it can be regarded as a Markov process.…

混沌动力学 · 物理学 2009-11-10 C. Collette , M. Ausloos

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…

太阳与恒星天体物理 · 物理学 2015-06-22 Susanta Kumar Bisoi , P. Janardhan , M. Ingale , P. Subramanian , S. Ananthakrishnan , M. Tokumaru , K. Fujiki

We use magnetic helicity to characterise solar wind fluctuations at proton-kinetic scales from Wind observations. For the first time, we separate the contributions to helicity from fluctuations propagating at angles quasi-parallel and…

We investigate possible links between the large-scale and small-scale features of solar wind fluctuations across the frequency break separating fluid and kinetic regimes. The aim is to correlate the magnetic field fluctuations polarization…

空间物理 · 物理学 2017-01-26 D. Telloni , R. Bruno

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…

太阳与恒星天体物理 · 物理学 2026-04-09 Yoshiki Hatta , Yuuki Nakano , Sho Sugama , Masanobu Kunitomo , Hiroshi Ito , Takashi Sekii

The solar wind is highly structured in fast and slow flows. These two dynamical regimes remarkably differ not only for the average values of magnetic field and plasma parameters but also for the type of fluctuations they transport. Fast…

太阳与恒星天体物理 · 物理学 2017-08-04 R. Bruno , D. Telloni , D. DeIure , E. Pietropaolo