scholarly journals The influence of solar wind turbulence on geomagnetic activity

2008 ◽  
Vol 15 (1) ◽  
pp. 53-59 ◽  
Author(s):  
D. Jankovičovà ◽  
Z. Vörös ◽  
J. Šimkanin
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Magnetic Reconnection ◽  
Interplanetary Magnetic Field ◽  
Space Weather ◽  
Coupled System ◽  
Statistical Moment ◽  
The Sun ◽  
H Index ◽  
Magnetic Turbulence

Abstract. The importance of space weather and its forecasting is growing as interest in studying geoeffective processes in the Sun – solar wind – magnetosphere – ionosphere coupled system is increasing. In this paper higher order statistical moments of interplanetary magnetic field and geomagnetic SYM-H index fluctuations are compared. The proper description of fluctuations in the solar wind can elucidate important aspects of the geoeffectivity of upstream turbulence and contribute to our understanding of space weather. Our results indicate that quasi-stationary intervals during both quiet and stormy periods have to be investigated in order to find correlations between upstream and geomagnetic conditions. We found that the fourth statistical moment (kurtosis), which was not considered in previous studies, appears to be a new geoeffective parameter. Intermittency of the magnetic turbulence in the solar wind can influence the efficiency of the solar wind – magnetosphere coupling through affecting magnetic reconnection at the Earth's magnetopause.

scholarly journals The effect of upstream turbulence and its anisotropy on the efficiency of solar wind – magnetosphere coupling

2008 ◽  
Vol 15 (4) ◽  
pp. 523-529 ◽  
Author(s):  
D. Jankovičová ◽  
Z. Vörös ◽  
J. Šimkanin
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Selection Criteria ◽  
Geomagnetic Storms ◽  
Coupled System ◽  
Proper Selection ◽  
H Index ◽  
Magnetic Turbulence ◽  
Two Measures ◽  
Index Time Series

Abstract. The importance of space weather and its forecasting is growing as interest in studying geoeffective processes in the Sun – solar wind – magnetosphere – ionosphere coupled system is increasing. This paper introduces the proper selection criteria for solar wind magnetic turbulence events during duskward electric field and southward Bz driven geomagnetic storms. Two measures for the strength of solar wind fluctuations were investigated: the standard deviations of magnetic field components and a proxy for the so-called Shebalin anisotropy angles. These measures were compared to the strength of geomagnetic storms obtained from a SYM-H index time series. We found a weak correlation between standard deviation of interplanetary magnetic field GSM component Bz and SYM-H index, and a strong correlation between Shebalin anisotropy angle and the SYM-H index, which can be the result of an increase of probability of magnetic reconnection in fluctuating magnetic fields.

The Sun

2015 ◽  
Author(s):  
Joanna D. Haigh ◽  
Peter Cargill
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Solar Atmosphere ◽  
Space Weather ◽  
Extreme Ultraviolet ◽  
The Sun ◽  
Base Level ◽  
Earth’S Climate ◽  
The Magnetic Field ◽  
Terrestrial Magnetic Field

This chapter discusses how there are four general factors that contribute to the Sun's potential role in variations in the Earth's climate. First, the fusion processes in the solar core determine the solar luminosity and hence the base level of radiation impinging on the Earth. Second, the presence of the solar magnetic field leads to radiation at ultraviolet (UV), extreme ultraviolet (EUV), and X-ray wavelengths which can affect certain layers of the atmosphere. Third, the variability of the magnetic field over a 22-year cycle leads to significant changes in the radiative output at some wavelengths. Finally, the interplanetary manifestation of the outer solar atmosphere (the solar wind) interacts with the terrestrial magnetic field, leading to effects commonly called space weather.

Extreme event theory applied to the solar wind

2021 ◽  
Author(s):  
Carlos Larrodera ◽  
Lidia Nikitina ◽  
Consuelo Cid
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Interplanetary Magnetic Field ◽  
Space Weather ◽  
Extreme Event ◽  
Extreme Value Distribution ◽  
Value Theory ◽  
Extreme Value ◽  
Parameter Analysis ◽  
Solar Cycles

<p>Society’s dependence on technology has increased during the past years. Therefore, understanding the hazardous events including space weather events that lead to technological problems is now critical. As solar wind is the driver of space weather, identifying extreme solar wind is important. In this work extreme value theory is used to characterize the solar wind parameters most relevant to space weather: interplanetary magnetic field strength and proton speed. This is done using an extreme value distribution for all data above a certain threshold for each parameter. Analysis demonstrates that these thresholds are around 900 km/s for the proton speed and around 95 nT for the interplanetary magnetic field. Based on 20 years of solar wind data, we made an estimation for the interplanetary magnetic field and solar wind proton speed with return periods corresponding to 4 and 6 solar cycles with a 99% confidence interval.</p>

scholarly journals The role of magnetic handedness in magnetic cloud propagation

2010 ◽  
Vol 28 (5) ◽  
pp. 1075-1100 ◽  
Author(s):  
U. Taubenschuss ◽  
N. V. Erkaev ◽  
H. K. Biernat ◽  
C. J. Farrugia ◽  
C. Möstl ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Magnetic Reconnection ◽  
Interplanetary Magnetic Field ◽  
Equatorial Plane ◽  
Magnetic Clouds ◽  
Geometrical Parameters ◽  
Meridional Plane ◽  
Mhd Simulations

Abstract. We investigate the propagation of magnetic clouds (MCs) through the inner heliosphere using 2.5-D ideal magnetohydrodynamic (MHD) simulations. A numerical solution is obtained on a spherical grid, either in a meridional plane or in an equatorial plane, by using a Roe-type approximate Riemann solver in the frame of a finite volume approach. The structured background solar wind is simulated for a solar activity minimum phase. In the frame of MC propagation, special emphasis is placed on the role of the initial magnetic handedness of the MC's force-free magnetic field because this parameter strongly influences the efficiency of magnetic reconnection between the MC's magnetic field and the interplanetary magnetic field. Magnetic clouds with an axis oriented perpendicular to the equatorial plane develop into an elliptic shape, and the ellipse drifts into azimuthal direction. A new feature seen in our simulations is an additional tilt of the ellipse with respect to the direction of propagation as a direct consequence of magnetic reconnection. During propagation in a meridional plane, the initial circular cross section develops a concave-outward shape. Depending on the initial handedness, the cloud's magnetic field may reconnect along its backside flanks to the ambient interplanetary magnetic field (IMF), thereby losing magnetic flux to the IMF. Such a process in combination with a structured ambient solar wind has never been analyzed in detail before. Furthermore, we address the topics of force-free magnetic field conservation and the development of equatorward flows ahead of a concave-outward shaped MC. Detailed profiles are presented for the radial evolution of magnetoplasma and geometrical parameters. The principal features seen in our MHD simulations are in good agreement with in-situ measurements performed by spacecraft. The 2.5-D studies presented here may serve as a basis under more simple geometrical conditions to understand more complicated effects seen in 3-D simulations.

scholarly journals Dynamics of the terrestrial radiation belts: a review of recent results during the VarSITI (Variability of the Sun and Its Terrestrial Impact) era, 2014–2018

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shrikanth Kanekal ◽  
Yoshizumi Miyoshi
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Magnetic Reconnection ◽  
Ring Current ◽  
Plasma Waves ◽  
Radiation Belts ◽  
The Sun ◽  
Plasma Convection ◽  
Outer Radiation Belt ◽  
Inner Magnetosphere

AbstractThe Earth’s magnetosphere is region that is carved out by the solar wind as it flows past and interacts with the terrestrial magnetic field. The inner magnetosphere is the region that contains the plasmasphere, ring current, and the radiation belts all co-located within about 6.6 Re, nominally taken to be bounding this region. This region is highly dynamic and is home to a variety of plasma waves and particle populations ranging in energy from a few eV to relativistic and ultra-relativistic electrons and ions. The interplanetary magnetic field (IMF) embedded in the solar wind via the process of magnetic reconnection at the sub-solar point sets up plasma convection and creates the magnetotail. Magnetic reconnection also occurs in the tail and is responsible for explosive phenomena known as substorms. Substorms inject low-energy particles into the inner magnetosphere and help generate and sustain plasma waves. Transients in the solar wind such as coronal mass ejections (CMEs), co-rotating interaction regions (CIRs), and interplanetary shocks compress the magnetosphere resulting in geomagnetic storms, energization, and loss of energetic electrons in the outer radiation belt nad enhance the ring current, thereby driving the geomagnetic dynamics. The Specification and Prediction of the Coupled Inner-Magnetospheric Environment (SPeCIMEN) is one of the four elements of VarSITI (Variability of the Sun and Its Terrestrial Impact) program which seeks to quantitatively predict and specify the inner magnetospheric environment based on Sun/solar wind driving inputs. During the past 4 years, the SPeCIMEN project has brought together scientists and researchers from across the world and facilitated their efforts to achieve the project goal. This review provides an overview of some of the significant scientific advances in understanding the dynamical processes and their interconnectedness during the VarSITI era. Major space missions, with instrument suites providing in situ measurements, ground-based programs, progress in theory, and modeling are briefly discussed. Open outstanding questions and future directions of inner magnetospheric research are explored.

Discontinuity analysis and evolution of magnetic switchbacks

2021 ◽  
Author(s):  
Mojtaba Akhavan-Tafti ◽  
Justin Kasper ◽  
Jia Huang ◽  
Stuart Bale
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Magnetic Reconnection ◽  
Mass Flux ◽  
Minimum Variance ◽  
Shear Angle ◽  
The Sun ◽  
Magnetic Shear ◽  
Global Circulation ◽  
Magnetic Signatures

<p>Magnetic switchbacks are Alfvénic structures characterized as intervals of intermittent reversals in the radial componentof magnetic field. Switchbacks comprise of magnetic spikes preceded/succeeded by quiet, pristine solar wind. Determining switch-back generation and evolution mechanisms will further our understanding of the global circulation and transportation of Sun’s openmagnetic flux. Here, we investigate switchback transition regions using measurements from fields and plasma suites aboard the Parker SolarProbe (PSP). Minimum variance analysis (MVA) is applied on switchback transition region magnetic signatures. Discontinuity analysesare performed on 273 switchback transition regions with robust MVA solutions. Our results indicate that switchbacks are rotational discontinuities (RD) in 214 (or 78%) of the cases. 21% of the switchbacktransition regions are categorized as "either" discontinuity (ED), defined as small relative changes in both magnitude and the normalcomponent of magnetic field. RD-to-ED event count is found to reduce with increasing distance from the Sun. On average, plasmabeta falls by −28% across RD-type switchback transition regions and magnetic shear angle is 60 [deg], therefore making switchbacktransition regions theoretically favorable to local magnetic reconnection. The evolution of switchbacks away from the Sun may involve increasing mass flux across RD-type switchback transition regions. The evolution mechanism(s) remain to be discovered. Our results indicate negligible magnetic curvature across switchback transition regions which may inhibit local magnetic reconnection.</p>

Coherent structures and magnetic reconnection in photospheric and interplanetary magnetic field turbulence

2019 ◽  
Vol 15 (S354) ◽  
pp. 351-354
Author(s):  
Rodrigo A. Miranda ◽  
Abraham C.-L. Chian ◽  
Erico L. Rempel ◽  
Suzana S. A. Silva
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Magnetic Reconnection ◽  
Interplanetary Magnetic Field ◽  
Coherent Structures ◽  
Lagrangian Coherent Structures ◽  
Inertial Subrange ◽  
Magnetic Elements ◽  
Transport Barriers ◽  
Magnetic Field Turbulence

AbstractIn this paper it is shown that rope-rope magnetic reconnection in the solar wind can enhance multifractality in the inertial subrange and drive intermittent magnetic field turbulence. Additionally, it is shown that Lagrangian coherent structures can unveil the transport barriers of magnetic elements in the quiet Sun.

scholarly journals On the scaling of waiting-time distributions of the negative IMF <i>B<sub>z</sub></i> component

2006 ◽  
Vol 24 (10) ◽  
pp. 2735-2741 ◽  
Author(s):  
R. D'Amicis ◽  
R. Bruno ◽  
B. Bavassano ◽  
V. Carbone ◽  
L. Sorriso-Valvo
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Solar Activity ◽  
Solar Cycle ◽  
Interplanetary Magnetic Field ◽  
Power Law ◽  
Waiting Time ◽  
The Sun ◽  
Activity Phase ◽  
Solar Wind Parameters

Abstract. Statistics associated with the fluctuations in solar wind parameters show a remarkable dependence on the solar activity phase. In particular, we focus our attention on the waiting-time statistics governing the MHD fluctuations of the z-component of the interplanetary magnetic field, which are important within the framework of the Sun-Earth connections, and briefly discuss the preliminary results. Data from several spacecrafts, covering different phases of the solar cycle and different radial distances, are used. We found that propagating Alfvénic fluctuations and convected structures strongly influence the statistics which vary from quasi-Poissonian to power law.

H-Cmes and Ii-Type Radio Bursts Related Intense Geomagnetic Storms in Relation With Interplanetary Magnetic Field and Solar Wind Disturbances

2012 ◽  
Vol 2 (10) ◽  
pp. 1-3 ◽  
Author(s):  
Praveen Kumar Gupta ◽  
◽  
Puspraj Singh Puspraj Singh ◽  
Puspraj Singh Puspraj Singh ◽  
P. K. Chamadia P. K. Chamadia
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Interplanetary Magnetic Field ◽  
Geomagnetic Storms ◽  
Radio Bursts ◽  
Solar Wind Disturbances
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