scholarly journals Understanding the variability of magnetic storms caused by ICMEs

2017 ◽  
Vol 35 (1) ◽  
pp. 147-159 ◽  
Author(s):  
Remi Benacquista ◽  
Sandrine Rochel ◽  
Guy Rolland
Keyword(s):  
Solar Wind ◽  
Magnetic Structure ◽  
Large Scale ◽  
Temporal Dynamics ◽  
Magnetic Storms ◽  
Magnetic Clouds ◽  
Interplanetary Coronal Mass Ejections ◽  
Superposed Epoch Analysis ◽  
Original Insight ◽  
Ambient Solar Wind

Abstract. In this paper, we study the dynamics of magnetic storms due to interplanetary coronal mass ejections (ICMEs). We used multi-epoch superposed epoch analyses (SEAs) with a choice of epoch times based on the structure of the events. By sorting the events with respect to simple large-scale features (presence of a shock, magnetic structure, polarity of magnetic clouds), this method provides an original insight into understanding the variability of magnetic storm dynamics. Our results show the necessity of seeing ICMEs and their preceding sheaths as a whole since each substructure impacts the other and has an effect on its geoeffectiveness. It is shown that the presence of a shock drives the geoeffectiveness of the sheaths, while both the shock and the magnetic structure impact the geoeffectiveness of the ICMEs. In addition, we showed that the ambient solar wind characteristics are not the same for ejecta and magnetic clouds (MCs). The ambient solar wind upstream magnetic clouds are quieter than upstream ejecta and particularly slower. We also focused on the polarity of magnetic clouds since it drives not only their geoeffectiveness but also their temporal dynamics. South–north magnetic clouds (SN-MCs) and north–south magnetic clouds (NS-MCs) show no difference in geoeffectiveness for our sample of events. Lastly, since it is well-known that sequences of events can possibly induce strong magnetic storms, such sequences have been studied using superposed epoch analysis (SEA) for the first time. We found that these sequences of ICMEs are very usual and concern about 40 % of the ICMEs. Furthermore, they cause much more intense magnetic storms than isolated events do.

scholarly journals Specific interplanetary conditions for CIR-, Sheath-, and ICME-induced geomagnetic storms obtained by double superposed epoch analysis

2010 ◽  
Vol 28 (12) ◽  
pp. 2177-2186 ◽  
Author(s):  
Yu. I. Yermolaev ◽  
N. S. Nikolaeva ◽  
I. G. Lodkina ◽  
M. Yu. Yermolaev
Keyword(s):  
Large Scale ◽  
Geomagnetic Storms ◽  
Magnetic Cloud ◽  
Magnetic Storms ◽  
Main Phase ◽  
Corotating Interaction Region ◽  
Superposed Epoch Analysis ◽  
Epoch Analysis ◽  
Archive Data ◽  
Scale Types

Abstract. A comparison of specific interplanetary conditions for 798 magnetic storms with Dst <−50 nT during 1976–2000 was made on the basis of the OMNI archive data. We categorized various large-scale types of solar wind as interplanetary drivers of storms: corotating interaction region (CIR), Sheath, interplanetary CME (ICME) including both magnetic cloud (MC) and Ejecta, separately MC and Ejecta, and "Indeterminate" type. The data processing was carried out by the method of double superposed epoch analysis which uses two reference times (onset of storm and minimum of Dst index) and makes a re-scaling of the main phase of the storm in a such way that all storms have equal durations of the main phase in the new time reference frame. This method reproduced some well-known results and allowed us to obtain some new results. Specifically, obtained results demonstrate that (1) in accordance with "output/input" criteria the highest efficiency in generation of magnetic storms is observed for Sheath and the lowest one for MC, and (2) there are significant differences in the properties of MC and Ejecta and in their efficiencies.

Ion-scale break of the plasma fluctuation spectra in different large-scale solar wind streams

2021 ◽  
Author(s):  
Maria Riazantseva ◽  
Liudmila Rakhmanova ◽  
Yuri Yermolaev ◽  
Irina Lodkina ◽  
Georgy Zastenker ◽  
...  
Keyword(s):  
Solar Wind ◽  
Large Scale ◽  
Plasma Heating ◽  
Coronal Holes ◽  
Magnetic Clouds ◽  
Alfven Wave ◽  
Slow Solar Wind ◽  
P Value ◽  
High Temporal Resolution ◽  
Turbulent Cascade

&lt;p&gt;Appearance of measurements of the interplanetary medium parameters with high temporal resolution gave rise to a variety of investigations of turbulent cascade at ion kinetic scales at which processes of plasma heating was believed to operate. Our recent studies based on high frequency plasma measurements at Spektr-R spacecraft have shown that the turbulent cascade was not stable and dynamically changed depending on the plasma conditions in different large-scale solar wind structures. These changes was most significant at the kinetic scales of the turbulent cascade. Slow undisturbed solar wind was characterized by the consistency of the spectra to the predictions of the kinetic Alfven wave turbulence model. On the other hand, the discrepancy between the model predictions and registered spectra were found in stream interaction regions characterized by crucial steepening of spectra at the kinetic scales with slopes having values up to -(4-5). This discrepancy was clearly shown for plasma compression region Sheath in front of the magnetic clouds and CIR in front of high speed streams associated with coronal holes. Present study is focused on the break preceding the kinetic scales. Currently the characteristic plasma parameters associated with the formation of the break is still debated. Number of studies demonstrated that the break was consistent with distinct characteristic frequencies for different values &amp;#8203;&amp;#8203;of the plasma proton parameter beta &amp;#946;p. Present study consider the ratio between the break frequency determined for ion flux fluctuation spectra according to Spektr-R data and several characteristic plasma frequencies used traditionally in such cases. The value of this ratio is statistically compared for different large-scale solar wind streams. We analyze both the classical spectrum view with two slopes and one break and the spectrum with flattening between magnetohydrodynamic and kinetic scales.&amp;#160; Our results show that for the Sheath and CIR regions characterized typically by &amp;#946;p &amp;#8804;1 the break corresponds statistically to the frequency determined by the proton gyroradius. At the same time such correspondence are not observed either for the undisturbed slow solar wind with similar &amp;#946;p value or for disturbed flows associated with interplanetary manifestations of coronal mass ejections, where &amp;#946;p &lt;&lt; 1. The results also shows that in slow undisturbed solar wind the break is closer to the frequency determined by the inertial proton length. Thus, apparently the transition between streams of different speeds may result in the change of dissipation regimes and plays role in plasma heating at these areas. This work was supported by the RFBR grant No. 19-02-00177a&lt;/p&gt;

CIR versus CME drivers of the ring current during intense magnetic storms

2010 ◽  
Vol 466 (2123) ◽  
pp. 3305-3328 ◽  
Author(s):  
Michael W. Liemohn ◽  
Matt Jazowski ◽  
Janet U. Kozyra ◽  
Natalia Ganushkina ◽  
Michelle F. Thomsen ◽  
...  
Keyword(s):  
Solar Wind ◽  
Boundary Conditions ◽  
Electric Fields ◽  
Data Model ◽  
Goodness Of Fit ◽  
Plasma Boundary ◽  
Magnetic Storms ◽  
Hot Electron ◽  
Interplanetary Coronal Mass Ejections ◽  
Interaction Regions

Ninety intense magnetic storms (minimum Dst value of less than −100 nT) from solar cycle 23 (1996–2005) were simulated using the hot electron and ion drift integrator (HEIDI) model. All 90 storm intervals were run with several electric fields and nightside plasma boundary conditions (five run sets). Storms were classified according to their solar wind driver, including corotating interaction regions (CIRs) and interplanetary coronal mass ejections (ICMEs). Data-model comparisons were made against the observed Dst index (specifically, Dst*) and dayside hot-ion measurements from geosynchronous orbiting spacecraft. It is found that the data-model goodness-of-fit values are different for CIR-driven storms relative to ICME-driven storms. The results are also different for the same storm category for different boundary conditions. None of the CIR-driven events was overpredicted by HEIDI, while the dayside comparisons were comparable for the different drivers. The results imply that the outer magnetosphere is responding differently to the two kinds of solar wind drivers, even though the resulting storm size might be similar. That is, for ICME-driven events, magnetospheric currents inside of geosynchronous orbit dominate the Dst perturbation, while for CIR-driven events, currents outside of this boundary have a systematically larger contribution.

scholarly journals Dynamics of large‐scale solar wind streams obtained by the double superposed epoch analysis

2015 ◽  
Vol 120 (9) ◽  
pp. 7094-7106 ◽  
Author(s):  
Yu. I. Yermolaev ◽  
I. G. Lodkina ◽  
N. S. Nikolaeva ◽  
M. Yu. Yermolaev
Keyword(s):  
Solar Wind ◽  
Large Scale ◽  
Superposed Epoch Analysis ◽  
Epoch Analysis

scholarly journals GUMICS-4 analysis of interplanetary coronal mass ejection impact on Earth during low and typical Mach number solar winds

2019 ◽  
Vol 37 (4) ◽  
pp. 561-579 ◽  
Author(s):  
Antti Lakka ◽  
Tuija I. Pulkkinen ◽  
Andrew P. Dimmock ◽  
Emilia Kilpua ◽  
Matti Ala-Lahti ◽  
...  
Keyword(s):  
Solar Wind ◽  
Mach Number ◽  
Large Scale ◽  
Space Environment ◽  
Interplanetary Coronal Mass Ejections ◽  
Solar Winds ◽  
Interplanetary Coronal Mass Ejection ◽  
Local Measurements ◽  
Upstream Solar Wind ◽  
Global And Local

Abstract. We study the response of the Earth's magnetosphere to fluctuating solar wind conditions during interplanetary coronal mass ejections (ICMEs) using the Grand Unified Magnetosphere-Ionosphere Coupling Simulation (GUMICS-4). The two ICME events occurred on 15–16 July 2012 and 29–30 April 2014. During the strong 2012 event, the solar wind upstream values reached up to 35 particles cm−3, speeds of up to 694 km s−1, and an interplanetary magnetic field of up to 22 nT, giving a Mach number of 2.3. The 2014 event was a moderate one, with the corresponding upstream values of 30 particles cm−3, 320 km s−1 and 10 nT, indicating a Mach number of 5.8. We examine how the Earth's space environment dynamics evolves during both ICME events from both global and local perspectives, using well-established empirical models and in situ measurements as references. We show that on the large scale, and during moderate driving, the GUMICS-4 results are in good agreement with the reference values. However, the local values, especially during high driving, show more variation: such extreme conditions do not reproduce local measurements made deep inside the magnetosphere. The same appeared to be true when the event was run with another global simulation. The cross-polar cap potential (CPCP) saturation is shown to depend on the Alfvén–Mach number of the upstream solar wind. However, care must be taken in interpreting these results, as the CPCP is also sensitive to the simulation resolution.

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

&lt;p&gt;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.&amp;#160; 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&amp;#8211;13 mHz over several periods of diminishing amplitudes.&amp;#160; 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.&lt;/p&gt;

CME arrival time predictions with a deformable front

2021 ◽  
Author(s):  
Jürgen Hinterreiter ◽  
Tanja Amerstorfer ◽  
Martin A. Reiss ◽  
Andreas J. Weiss ◽  
Christian Möstl ◽  
...  
Keyword(s):  
Solar Wind ◽  
Large Scale ◽  
Arrival Time ◽  
Interplanetary Space ◽  
Solar Wind Speed ◽  
Model Combination ◽  
First Results ◽  
Good Agreement ◽  
Ambient Solar Wind

&lt;p&gt;We present the first results of our newly developed CME arrival prediction model, which allows the CME front to deform and adapt to the changing solar wind conditions.&amp;#160;Our model is based on ELEvoHI and makes use of the WSA/HUX (Wang-Sheeley-Arge/Heliospheric Upwind eXtrapolation) model combination, which computes large-scale ambient solar wind conditions in the interplanetary space. With an estimate of the solar wind speed and density, we are able to account for the drag exerted on different parts of the CME front.&amp;#160;Initially, our model relies on heliospheric imager observations to confine an elliptical CME front and to obtain an initial speed and drag parameter for the CME. After a certain distance, each point of the CME front is propagating based on the conditions in the heliosphere. In this case study, we compare our results to previous arrival time predictions using ELEvoHI with a rigid CME front. We find that the actual arrival time at Earth and the arrival time predicted by the new model are in very good agreement.&lt;/p&gt;

Small-scale variations of helium abundance in different large-scale solar wind structures

2020 ◽  
Author(s):  
Alexander Khokhlachev ◽  
Maria Riazantseva ◽  
Liudmila Rakhmanova ◽  
Yuri Yermolaev ◽  
Irina Lodkina ◽  
...  
Keyword(s):  
Solar Wind ◽  
Large Scale ◽  
Solar Wind Plasma ◽  
Magnetic Clouds ◽  
Slow Solar Wind ◽  
Small Scale ◽  
Plasma Stream ◽  
Helium Abundance ◽  
Russian Science ◽  
Plasma Parameters

&lt;p&gt;The boundaries between large-scale solar wind streams are often accompanied by sharp changes in helium abundance. &amp;#160;Wherein the high value of relative helium abundance is known as a sign of some large-scale solar wind structures ( for example magnetic clouds). Unlike the steady slow solar wind where the helium abundance is rather stable and equals ~5%, in magnetic clouds its value can grow significantly up to 20% and more, and at the same time helium component becomes more variable. &amp;#160;In this paper we analyze the small-scale variations of solar wind plasma parameters, including the helium abundance variations in different large-scale solar wind streams, especially in magnetic clouds and Sheath regions before them. We use rather long intervals of simultaneous measurements at Spektr-R (spectrometer BMSW) and Wind (spectrometer 3DP) spacecrafts. &amp;#160;We choose the intervals with rather high correlation &amp;#160;level of plasma parameters as a whole to be sure that we are deal with the same plasma stream. &amp;#160;The intervals associated with different large scale-solar wind structures are selected by using of our catalog ftp://ftp.iki.rssi.ru/pub/omni/catalog/. For selected intervals we examine cross-correlation function for Spektr-R and Wind measurements &amp;#160;to reveal the local spatial inhomogeneities by helium abundance which can be observed only at one of spacecrafts, and we determine properties of ones. Such inhomogeneities can be generate by turbulence, which is typically getting more intense in the considered disturbed intervals in the solar wind. The work is supported by Russian Science Foundation grant 16-12-10062.&lt;/p&gt;

The Hilbert-Huang Transform (HHT) as a tool for characterizing dynamical features of Mercury’s and Venus’ magnetospheres

2020 ◽  
Author(s):  
Tommaso Alberti ◽  
Anna Milillo ◽  
Monica Laurenza ◽  
Stefano Massetti ◽  
Stavro Ivanovski ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Large Scale ◽  
Global Features ◽  
Hilbert Huang Transform ◽  
Ulf Wave ◽  
Local And Global Features ◽  
Spatio Temporal ◽  
Planetary Magnetic Field ◽  
Ambient Solar Wind

&lt;p class=&quot;western&quot; align=&quot;justify&quot;&gt;&lt;span&gt;The interaction between the interplanetary medium and planetary environments gives rise to different phenomena according to the spatio-temporal scales. Here we apply for the first time a novel data analysis method, i.e., the Hilbert-Huang Transform, to discriminate both local and global properties of Venus&amp;#8217; and Mercury&amp;#8217;s environments as seen during two MESSENGER flybys. Hence, we may infer that the near-Venus environment is similar in terms of local and global features to the ambient solar wind, possibly related to the induced nature of Venus&amp;#8217; magnetosphere. Conversely, the near-Mercury environment presents some different local features with respect to the ambient solar wind, due to both interaction processes and intrinsic structures of the Hermean environment. Our findings support the ion kinetic nature of the Hermean plasma structures, with the foreshock and the magnetosheath regions being characterized by inhomogeneous ion-kinetic intermittent fluctuations, together with MHD and large-scale fluctuations, the latter being representative of the main structure of the magnetosphere. We also show that the HHT analysis allow to capture and reproduce some interesting features of the Hermean environment as flux transfer events, Kelvin-Helmholtz vortex, and ULF wave activity, thus providing a suitable method for characterizing physical processes of different nature. Our approach demonstrate to be very promising for the characterization of the structure and dynamics of planetary magnetic field at different scales, for the identification of different planetary regions, and for the detection of the &amp;#8220;effective&amp;#8221; planetary magnetic field that can be used for modelling purposes.&lt;/span&gt;&lt;/p&gt;

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