中文
相关论文

相关论文: On the Relationship between Magnetic Expansion Fac…

200 篇论文

Hot flow anomalies (HFAs) are studied using observations of the RAPID suprathermal charged particle detector, the FGM magnetometer, and the CIS plasma detector aboard the four Cluster spacecraft. Previously, we studied several specific…

During Parker Solar Probe (Parker) Encounter 15 (E15), we observe an 18-hour period of near subsonic ($\mathrm{M_S \sim}$ 1) and sub-Alfv\'enic (SA), $\mathrm{M_A}$ <<< 1, slow speed solar wind from 22 to 15.6 R$_\odot$. As the most extreme…

Current solar wind prediction is based on the Wang & Sheeley empirical relationship between the solar wind speed observed at 1 AU and the rate of magnetic flux tube expansion (FTE) between the photosphere and the inner corona, where FTE is…

太阳与恒星天体物理 · 物理学 2020-10-21 Bala Poduval , Gordon Petrie , Luca Bertello

Two states of the slow solar wind are identified from in-situ measurements by Parker Solar Probe (PSP) inside 50 solar radii from the Sun. At such distances the wind measured at PSP has not yet undergone significant transformation related…

太阳与恒星天体物理 · 物理学 2021-04-07 Léa Griton , Alexis P. Rouillard , Nicolas Poirier , Karine Issautier , Michel Moncuquet , Rui Pinto

Coronal holes (CHs) are regions of open magnetic flux which are the source of high speed solar wind (HSSW) streams. To date, it is not clear which aspects of CHs are of most influence on the properties of the solar wind as it expands…

太阳与恒星天体物理 · 物理学 2018-12-12 Tadhg M. Garton , Sophie A. Murray , Peter T. Gallagher

Two populations of twisted magnetic field tubes, or flux ropes (hereafter, FRs), are detected by in situ measurements in the solar wind. While small FRs are crossed by the observing spacecraft within few hours, with a radius typically less…

太阳与恒星天体物理 · 物理学 2015-06-22 M. Janvier , P. Demoulin , S. Dasso

One of the basic properties of the solar wind, that is the high speed of the fast wind, is still not satisfactorily explained. This is mainly due to the theoretical difficulty of treating weakly collisional plasmas. The fluid approach…

天体物理学 · 物理学 2009-11-11 I. Zouganelis , N. Meyer-Vernet , S. Landi , M. Maksimovic , F. Pantellini

$PSP$ and $SolO$ data are utilized to investigate magnetic field intermittency in the solar wind (SW). Small-scale intermittency $(20-100d_{i})$ is observed to radially strengthen when methods relying on higher-order moments are considered…

Kinetic exospheric models revealed that the solar wind is accelerated by an ambipolar electric field up to supersonic velocities. The presence of suprathermal Strahl electrons at the exobase can further increase the velocity to higher…

太阳与恒星天体物理 · 物理学 2024-01-25 Viviane Pierrard , Maximilien Peters de Bonhome

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…

The rate at which the solar wind extracts angular momentum from the Sun has been predicted by theoretical models for many decades, and yet we lack a conclusive measurement from in-situ observations. In this letter we present a new estimate…

太阳与恒星天体物理 · 物理学 2019-11-27 Adam J. Finley , Amy L. Hewitt , Sean P. Matt , Mathew Owens , Rui F. Pinto , Victor Réville

Statistical classification of the Helios solar wind observations into several populations sorted by bulk speed has revealed an outward acceleration of the wind. The faster the wind is, the smaller is this acceleration in the 0.3 - 1 au…

太阳与恒星天体物理 · 物理学 2023-04-19 Dakeyo , Maksimovic , Démoulin , Halekas , Stevens

Analysis of the Interball-1 spacecraft data (1995-2000) has shown that the solar wind ion flux sometimes increases or decreases abruptly by more than 20% over a time period of several seconds or minutes. Typically, the amplitude of such…

空间物理 · 物理学 2011-02-08 Olga Khabarova , Georgy Zastenker

The long-term evolution of the Sun's rotation period cannot be directly observed, and is instead inferred from trends in the measured rotation periods of other Sun-like stars. Assuming the Sun spins-down as it ages, following rotation rate…

We introduce an updated, time-dependent treatment to the split-tail ("croissant-like") heliosphere model with data-driven solar wind conditions at 1 au, to study the evolution of the heliosphere with solar-cycle variations in plasma speed,…

太阳与恒星天体物理 · 物理学 2026-03-20 Chika Onubogu , M. Opher , E. Powell , S. Du , J. M. Sokół , J. D. Richardson , B. Van Der Holst

Recurrent, arc-shaped intensity disturbances were detected by EUV channels in an active region. The fronts were observed to propagate along a coronal loop bundle rooted in a small area within a sunspot umbra. Previous works have linked…

太阳与恒星天体物理 · 物理学 2022-11-02 M. V. Sieyra , S. Krishna Prasad , G. Stenborg , E. Khomenko , T. Van Doorsselaere , A. Costa , A. Esquivel , J. M. Riedl

(Abridged) Aim: We attempt to determine robust estimates of the heliospheric magnetic flux ($\Phi_H$) using Parker Solar Probe (PSP) data, analyze how susceptible this is to overestimation compared to the true open flux ($\Phi_{open}$),…

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…

天体物理学 · 物理学 2015-06-24 R. Bruno , V. Carbone , L. Sorriso-Valvo , B. Bavassano

Solar wind forecasting plays a crucial role in space weather prediction, yet significant uncertainties persist due to incomplete magnetic field observations of the Sun. Isolating the solar wind forecasting errors due to these effects is…

An accurate solar wind speed model is important for space weather predictions, catastrophic event warnings, and other issues concerning solar wind - magnetosphere interaction. In this work, we construct a model based on convolutional neural…

太阳与恒星天体物理 · 物理学 2023-04-05 Rong Lin , Zhekai Luo , Jiansen He , Lun Xie , Chuanpeng Hou , Shuwei Chen