scholarly journals Dynamics of the Electron Belts

2021 ◽  
pp. 213-240
Author(s):  
Hannu E. J. Koskinen ◽  
Emilia K. J. Kilpua
Keyword(s):  
Solar Wind ◽  
Large Scale ◽  
Geomagnetic Storms ◽  
Radiation Belts ◽  
Satellite Observations ◽  
Interplanetary Shocks ◽  
Outer Electron ◽  
Structure And Dynamics ◽  
The Earth ◽  
Pressure Pulses

AbstractIn this chapter we discuss the overall structure and dynamics of the electron belts and some of their peculiar features. We also consider the large-scale solar wind structures that drive geomagnetic storms and detail the specific responses of radiation belts on them. Numerous satellite observations have highlighted the strong variability of the outer electron belt and the slot region during the storms, and the energy and L-shell dependence of these variations. The belts can also experience great variations when interplanetary shocks or pressure pulses impact the Earth, even without a following storm sequence.

Magnetospheric response to solar wind driving

2021 ◽  
Author(s):  
Tatiana Výbošťoková ◽  
Zdeněk Němeček ◽  
Jana Šafránková
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Electric Field ◽  
Geomagnetic Storms ◽  
Interplanetary Space ◽  
Time Lags ◽  
Interplanetary Shocks ◽  
Geomagnetic Indices ◽  
The Earth ◽  
The Magnetic Field

<p>Interaction of solar events propagating throughout the interplanetary space with the magnetic field of the Earth may result in disruption of the magnetosphere. Disruption of the magnetic field is followed by the formation of the time-varying electric field and thus electric current is induced in Earth-bound structures such as transmission networks, pipelines or railways. In that case, it is necessary to be able to predict a future state of the magnetosphere and magnetic field of the Earth. The most straightforward way would use geomagnetic indices. Several studies are investigating the relationship of the response of the magnetosphere to changes in the solar wind with motivation to give a more accurate prediction of geomagnetic indices during geomagnetic storms. To forecast these indices, different approaches have been attempted--from simple correlation studies to neural networks.</p><p>We study the effects of interplanetary shocks observed at L1 on the Earth's magnetosphere with a database of tens of shocks between 2009 and 2019. Driving the magnetosphere is described as integral of reconnection electric field for each shock. The response of the geomagnetic field is described with the SYM-H index. We created an algorithm in Python for prediction of the magnetosphere state based on the correlation of solar wind driving and magnetospheric response and found that typical time-lags range between tens of minutes to maximum 2 hours. The results are documented by a large statistical study.</p>

scholarly journals Formation of a strong southward IMF near the solar maximum of cycle 23

2004 ◽  
Vol 22 (2) ◽  
pp. 673-687 ◽  
Author(s):  
S. Watari ◽  
M. Vandas ◽  
T. Watanabe
Keyword(s):  
Solar Wind ◽  
Magnetic Fields ◽  
Geomagnetic Storms ◽  
Solar Maximum ◽  
Interplanetary Shocks ◽  
Physical Processes ◽  
Interplanetary Magnetic Fields ◽  
Interplanetary Physics ◽  
Solar Wind Parameters ◽  
Interplanetary Disturbance

Abstract. We analyzed observations of the solar activities and the solar wind parameters associated with large geomagnetic storms near the maximum of solar cycle 23. This analysis showed that strong southward interplanetary magnetic fields (IMFs), formed through interaction between an interplanetary disturbance, and background solar wind or between interplanetary disturbances are an important factor in the occurrence of intense geomagnetic storms. Based on our analysis, we seek to improve our understanding of the physical processes in which large negative Bz's are created which will lead to improving predictions of space weather. Key words. Interplanetary physics (Flare and stream dynamics; Interplanetary magnetic fields; Interplanetary shocks)

Determining latitudinal extent of energetic electron precipitation using MEPED on-board NOAA POES

2020 ◽  
Author(s):  
Eldho Midhun Babu ◽  
Hilde Nesse Tyssøy ◽  
Christine Smith-Johnsen ◽  
Ville Aleksi Maliniemi ◽  
Josephine Alessandra Salice ◽  
...  
Keyword(s):  
Solar Wind ◽  
Radiation Belt ◽  
Climate Models ◽  
Stratospheric Ozone ◽  
Energetic Electron ◽  
Radiation Belts ◽  
Atmospheric Dynamics ◽  
Electron Precipitation ◽  
Atmospheric Effects ◽  
The Earth

<p>Energetic electron precipitation (EEP) from the plasma sheet and the radiation belts, can collide with gases in the atmosphere and deposit their energy. EEP increase the production of NOx and HOx, which will catalytically destroy stratospheric ozone, an important element of atmospheric dynamics. The particle precipitation also causes variation in the radiation belt population. Therefore, measurement of latitudinal extend of the precipitation boundaries is important in quantifying atmospheric effects of Sun-Earth interaction and threats to spacecrafts and astronauts in the Earth’s radiation belt. <br>This study uses measurements by MEPED detectors of six NOAA/POES and EUMETSAT/METOP satellites during the year 2010 to determine the latitudinal boundaries of EEP and its variability with geomagnetic activity and solar wind drivers. Variation of the boundaries with respect to different particle energies and magnetic local time is studied. The result will be a key element for constructing a model of EEP variability to be applied in atmosphere climate models.</p>

Global structure and dynamics of large-scale fluctuations in the solar wind: Voyager 2 observations during 2005 and 2006

2008 ◽  
Vol 113 (A2) ◽  
pp. n/a-n/a ◽  
Author(s):  
L. F. Burlaga ◽  
N. F Ness ◽  
M. H. Acũna ◽  
Y.-M. Wang ◽  
N. R. Sheeley ◽  
...  
Keyword(s):  
Solar Wind ◽  
Large Scale ◽  
Global Structure ◽  
Structure And Dynamics ◽  
Voyager 2

Space Weather

2015 ◽  
Author(s):  
Joanna D. Haigh ◽  
Peter Cargill
Keyword(s):  
Solar Wind ◽  
Solar Corona ◽  
Space Weather ◽  
Coronal Mass Ejections ◽  
Interplanetary Medium ◽  
Earth Satellite ◽  
Satellite Observations ◽  
Space Environment ◽  
The Sun ◽  
The Earth

This chapter focuses on the link between Sun and Earth generically known as space weather. This link is referred to as the occurrence in the solar corona of energetic phenomenon such as flares and coronal mass ejections which can have a major impact on the Earth's space environment. There were other discoveries in subsequent years, but the 1950s and 1960s brought major advances in the understanding of the connection between the Sun and the Earth. Satellite observations confirmed the existence of the solar wind, so that the nature of the interplanetary medium was identified and measured. Such continuous monitoring of the Sun and solar wind has, in turn, led to methods for predicting deleterious space weather.

Interplanetary Shock-driven Magnetopause Compressions in Gorgon Global-MHD Simulations

2021 ◽  
Author(s):  
Ravindra Desai ◽  
Jonathan Eastwood ◽  
Joseph Eggington ◽  
Mervyn Freeman ◽  
Martin Archer ◽  
...  
Keyword(s):  
Solar Wind ◽  
Large Scale ◽  
Interplanetary Shock ◽  
Interplanetary Shocks ◽  
Pressure Balance ◽  
Interplanetary Coronal Mass Ejections ◽  
Corotating Interaction Regions ◽  
Mhd Simulations ◽  
Interaction Regions ◽  
Space Weather Event

<p>Fast-forward interplanetary interplanetary shocks, as occur at the forefront of interplanetary coronal mass ejections and at corotating interaction regions, can rapidly compress the magnetopause inside the drift paths of electrons and protons, and expose geosynchonous satellites directly to the solar wind.  Here, we use Gorgon Global-MHD simulations to study the response of the magnetopause to different fast-forward interplanetary shocks, with strengths extending from the median shocks observed during solar minimum up to that representing an extreme space weather event. The subsequent magnetopause response can be characterised by three distinct phases; an initial acceleration as inertial forces are overcome, a rapid compression well-represented by a power law, and large-scale damped oscillatory motion of the order of an Earth radius, prior to reaching pressure-balance equilibrium. The subsolar magnetopause is found to oscillate with notable frequencies in the range of 2–13 mHz over several periods of diminishing amplitudes.  These results provide an explanation for similar large-scale magnetopause oscillations observed previously during the extreme events of August 1972 and March 1991 and highlight why static magnetopause models break down during periods of strong solar wind driving.</p>

A critical look at studying the interplanetary drivers of the magnetospheric disturbances

2020 ◽  
Author(s):  
Yuri Yermolaev ◽  
Irina Lodkina ◽  
Lidia Dremukhina ◽  
Michael Yermolaev ◽  
Alexander Khokhlachev
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Large Scale ◽  
Geomagnetic Storms ◽  
Interplanetary Shock ◽  
Complex Nature ◽  
Physics Of The Magnetosphere ◽  
Large Classes ◽  
Compression Region ◽  
Different Types

<p>Although the main types of solar wind (the so-called interplanetary drivers), which may contain the southward component of the interplanetary magnetic field (Bz <0) and cause disturbances in the magnetosphere, have long been known, it has only recently been discovered that different types of drivers cause a different reaction of the magnetosphere for identical field variations (Borovsky and Denton,2006, Yermolaev et al., 2013). This discovery led to a significant increase in the number of investigations studying the response of the magnetosphere-ionosphere system to various drivers. At the same time, the number of incorrect approaches in this direction of research has increased. These errors can be attributed to 4 large classes. (1) First class includes works whose authors uncritically reacted to previously published works and use incorrect results to identify types of drivers. (2) Some authors independently incorrectly identified driver types. (3) Very often, authors associate the perturbation of the magnetosphere-ionosphere system caused by a complex driver (a sequence of single drivers) with one of the drivers, ignoring the complex nature. For example, a magnetic storm is often caused by a compression region Sheath in front of an interplanetary CME (ICME), but the authors consider the ICME to be a cause of disturbance, not Sheath. (4) Finally, there is a “lost driver” of magnetospheric disturbances: some authors simply do not consider the Sheath compression region before ICME if there is no interplanetary shock (IS) before Sheath, although this type of driver, “Sheath without IS”, generates about 10% of moderate and strong geomagnetic storms (Yermolaev et al., 2017, 2020). These errors lead to numerous mistakes and incorrect conclusions.<br>The work is supported by the RFFI grant 19-02-00177а. </p><p>References<br>Borovsky, J. E., and M. H. Denton (2006), Differences between CME‐driven storms and CIR‐driven storms, J. Geophys. Res., 111, A07S08, doi:10.1029/2005JA011447</p><p>Yermolaev, Y. I., N. S. Nikolaeva, I. G. Lodkina, and M. Y. Yermolaev (2012), Geoeffectiveness and efficiency of CIR, sheath, and ICME in generation of magnetic storms, J. Geophys. Res., 117, A00L07, doi:10.1029/2011JA017139</p><p><br>Yermolaev, Y.I., Lodkina, I.G., Nikolaeva, N.S. et al. (2017), Some problems of identifying types of large-scale solar wind and their role in the physics of the magnetosphere, Cosmic Res. 55: 178. https://doi.org/10.1134/S0010952517030029</p><p>Yermolaev, Y.I., Lodkina, I.G., et al. (2020), Some problems of identifying types of large-scale solar wind and their role in the physics of the magnetosphere. 4. Lost driver, Cosmic Res. 59, in press</p><p> </p>

High-latitude ionospheric response to co-rotating interaction region- and coronal mass ejection-driven geomagnetic storms revealed by GPS tomography and ionosondes

2010 ◽  
Vol 466 (2123) ◽  
pp. 3391-3408 ◽  
Author(s):  
D. Pokhotelov ◽  
P. T. Jayachandran ◽  
C. N. Mitchell ◽  
M. H. Denton
Keyword(s):  
Solar Wind ◽  
Coronal Mass Ejection ◽  
Plasma Density ◽  
Large Scale ◽  
Geomagnetic Storms ◽  
Interaction Region ◽  
Electron Content ◽  
Polar Cap ◽  
Total Electron ◽  
Mass Ejection

Positive ionospheric anomalies induced in the polar cap region by co-rotating interaction region (CIR)- and coronal mass ejection (CME)-driven geomagnetic storms are analysed using four-dimensional tomographic reconstructions of the ionospheric plasma density based on measurements of the total electron content along ray paths of GPS signals. The results of GPS tomography are compared with ground-based observations of F region plasma density by digital ionosondes located in the Canadian Arctic. It is demonstrated that CIR- and CME-driven storms can produce large-scale polar cap anomalies of similar morphology in the form of the tongue of ionization (TOI) that appears on the poleward edge of the mid-latitude dayside storm-enhanced densities in positive ionospheric storms. The CIR-driven event of 14–16 October 2002 was able to produce ionospheric anomalies (TOI) comparable to those produced by the CME-driven storms of greater Dst magnitude. From the comparison of tomographic reconstructions and ionosonde data with solar wind measurements, it appears that the formation of large-scale polar cap anomalies is controlled by the orientation of the interplanetary magnetic field (IMF) with the TOI forming during the periods of extended southward IMF under conditions of high solar wind velocity.

scholarly journals Satellite observations of currents and waves in space plasmas

1988 ◽  
Vol 6 (3) ◽  
pp. 503-511 ◽  
Author(s):  
T. A. Potemra ◽  
M. J. Engebretson ◽  
L. J. Zanetti ◽  
R. E. Erlandson ◽  
P. F. Bythrow
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Geomagnetic Field ◽  
Large Scale ◽  
Field Experiments ◽  
Outer Space ◽  
Solar Wind Plasma ◽  
Field Configuration ◽  
The Earth ◽  
Field Lines

When viewed from outer space, the earth's magnetic field does not resemble a simple dipole, but is severely distorted into a comet-shaped configuration by the continuous flow of solar wind plasma. A complicated system of currents flows within this distorted magnetic field configuration called the ‘magnetosphere’ (See figure 1). For example, the compression of the geomagnetic field by the solar wind on the dayside of the earth is associated with a large-scale current flowing across the geomagnetic field lines, called the ‘Chapman-Ferraro’ or magnetopause current. The magnetospheric system includes large-scale currents that flow in the ‘tail’, the ring current that flows at high altitudes around the equator of the earth, field-aligned ‘Birkeland’ currents that flow along geomagnetic field lines into and away from the two auroral regions, and a complex system of currents that flows completely within the layers of the ionosphere, the earth's ionized atmosphere. The intensities of these various currents reach millions of amperes and are closely related to solar activity. The geomagnetic field lines can also oscillate, like giant vibrating strings, at specified resonant frequencies. The effects of these vibrations, sometimes described as ‘standing Alfvén waves’, have been observed on the ground in magnetic field recordings dating back to the beginning of the century. Observations of currents and waves with satellite-borne magnetic field experiments have provided a new perspective on the complicated plasma processes that occur in the magnetosphere. Some of the new observations are described here.

scholarly journals The Relationship Between Solar Wind Dynamic Pressure Pulses and Solar Wind Turbulence

2021 ◽  
Vol 9 ◽  
Author(s):  
Mengsi Ruan ◽  
Pingbing Zuo ◽  
Zilu Zhou ◽  
Zhenning Shen ◽  
Yi Wang ◽  
...  
Keyword(s):  
Solar Wind ◽  
Large Scale ◽  
Dynamic Pressure ◽  
Solar Wind Dynamic Pressure ◽  
Occurrence Rate ◽  
Time Lags ◽  
Gaussian Distributions ◽  
Solar Wind Turbulence ◽  
Wind Turbulence ◽  
Pressure Pulses

Solar wind dynamic pressure pulses (DPPs) are small-scale plasma structures with abrupt and large-amplitude plasma dynamic pressure changes on timescales of seconds to several minutes. Overwhelming majority of DPP events (around 79.13%) reside in large-scale solar wind transients, i.e., coronal mass ejections, stream interaction regions, and complex ejecta. In this study, the intermittency, which is a typical feature of solar wind turbulence, is determined and compared during the time intervals in the undisturbed solar wind and in large-scale solar wind transients with clustered DPP events, respectively, as well as in the undisturbed solar wind without DPPs. The probability distribution functions (PDFs) of the fluctuations of proton density increments normalized to the standard deviation at different time lags in the three types of distinct regions are calculated. The PDFs in the undisturbed solar wind without DPPs are near-Gaussian distributions. However, the PDFs in the solar wind with clustered DPPs are obviously non-Gaussian distributions, and the intermittency is much stronger in the large-scale solar wind transients than that in the undisturbed solar wind. The major components of the DPPs are tangential discontinuities (TDs) and rotational discontinuities (RDs), which are suggested to be formed by compressive magnetohydrodynamic (MHD) turbulence. There are far more TD-type DPPs than RD-type DPPs both in the undisturbed solar wind and large-scale solar wind transients. The results imply that the formation of solar wind DPPs could be associated with solar wind turbulence, and much stronger intermittency may be responsible for the high occurrence rate of DPPs in the large-scale solar wind transients.

Sign in / Sign up

Export Citation Format

Share Document