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.

scholarly journals Superposed epoch analysis of the dayside ionospheric response to four intense geomagnetic storms

2008 ◽  
Vol 113 (A3) ◽  
pp. n/a-n/a ◽  
Author(s):  
A. J. Mannucci ◽  
B. T. Tsurutani ◽  
M. A. Abdu ◽  
W. D. Gonzalez ◽  
A. Komjathy ◽  
...  
Keyword(s):  
Geomagnetic Storms ◽  
Ionospheric Response ◽  
Superposed Epoch Analysis ◽  
Epoch Analysis

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

Geoelectric field as a GIC proxy during the intense geomagnetic storms and Polish transmission lines failures occurrence

2021 ◽  
Author(s):  
Agnieszka Gil ◽  
Monika Berendt-Marchel ◽  
Renata Modzelewska ◽  
Szczepan Moskwa ◽  
Agnieszka Siluszyk ◽  
...  
Keyword(s):  
Transmission Lines ◽  
Geomagnetic Storms ◽  
Earth Model ◽  
Geoelectric Field ◽  
Self Organizing Maps ◽  
Superposed Epoch Analysis ◽  
Electrical Grid ◽  
Solar Origin ◽  
Cycle 24 ◽  
Epoch Analysis

&lt;p&gt;We study intense geomagnetic storms (Dst &lt; 100nT) during the first half of the solar cycle 24. This type of storm appeared only a few times, mostly associated with southwardly directed heliospheric magnetic field &amp;#160;B&lt;sub&gt;z&lt;/sub&gt; . Using various methodology as self-organizing maps, statistical and superposed epoch analysis, we show that during and right after intense geomagnetic storms, growth in the number of transmission lines failures, which might be of solar origin, appeared. We also examine the temporal changes in the number of failures during 2010-2014 and found the growing linear tendency of electrical grid failures occurrence possibly connected with solar activity. We confront these results with the geoelectric field calculated for the Poland region using a 1-D layered conductivity Earth model.&lt;/p&gt;

scholarly journals A Statistical Study of the Correlation between Geomagnetic Storms and M ≥ 7.0 Global Earthquakes during 1957–2020

Entropy ◽  
2020 ◽  
Vol 22 (11) ◽  
pp. 1270
Author(s):  
Hongyan Chen ◽  
Rui Wang ◽  
Miao Miao ◽  
Xiaocan Liu ◽  
Yonghui Ma ◽  
...  
Keyword(s):  
Electroosmotic Flow ◽  
Statistical Study ◽  
Geomagnetic Storms ◽  
Statistical Correlation ◽  
Superposed Epoch Analysis ◽  
Significance Analysis ◽  
Complex Process ◽  
Shallow Earthquakes ◽  
Statistical Studies ◽  
Epoch Analysis

In order to find out whether the geomagnetic storms and large-mega earthquakes are correlated or not, statistical studies based on Superposed Epoch Analysis (SEA), significance analysis, and Z test have been applied to the Dst index data and M ≥ 7.0 global earthquakes during 1957–2020. The results indicate that before M ≥ 7.0 global earthquakes, there are clearly higher probabilities of geomagnetic storms than after them. Geomagnetic storms are more likely to be related with shallow earthquakes rather than deep ones. Further statistical investigations of the results based on cumulative storm hours show consistency with those based on storm days, suggesting that the high probability of geomagnetic storms prior to large-mega earthquakes is significant and robust. Some possible mechanisms such as a reverse piezoelectric effect and/or electroosmotic flow are discussed to explain the statistical correlation. The result might open new perspectives in the complex process of earthquakes and the Lithosphere-Atmosphere-Ionosphere (LAI) coupling.

Superposed Epoch Analysis of High Latitude Ionospheric Joule Heating during Major Geomagnetic Storms over three Solar Cycles

2018 ◽  
Vol 13 (S340) ◽  
pp. 67-68
Author(s):  
K. J. Suji ◽  
P. R. Prince
Keyword(s):  
Solar Wind ◽  
Joule Heating ◽  
High Latitude ◽  
Geomagnetic Storms ◽  
Dynamic Pressure ◽  
Basic Structure ◽  
Proton Density ◽  
Solar Cycles ◽  
Superposed Epoch Analysis ◽  
Epoch Analysis

AbstractSuperposed epoch analysis (SPEA) is commonly used to determine some basic structure in a collection of geophysical time series. The present study tries to analyze ionospheric Joule heating response at high latitudes, to the prevailing solar wind and IMF conditions on the basis of SPEA. Major geomagnetic storms (CME driven) over three consecutive solar cycles (SC 22, 23 and 24) have been selected. Ascending phase, solar maximum, and declining phase are investigated separately, for each solar cycle, to find out crucial controlling parameters for the generation of high-latitude ionospheric Joule heating. SPEA results show that, IMF parameters such as IMF By, IMF Bz, IMF clock angle and solar wind parameters such as dynamic pressure and proton density influence Joule heating production rate significantly. Meanwhile, the relentlessness of the other parameters such as IMFBt and solar wind bulk speed show that they have poor impact on Joule heating.

scholarly journals Supersubstorms during strong magnetic storm on 7 September 2017

2019 ◽  
Vol 127 ◽  
pp. 01010
Author(s):  
Irina Despirak ◽  
Natalia Kleimenova ◽  
Liudmila Gromova ◽  
Sergey Gromov ◽  
Liudmila Malysheva
Keyword(s):  
Solar Wind ◽  
Magnetic Storm ◽  
Geomagnetic Storms ◽  
Magnetic Cloud ◽  
Global Scale ◽  
Main Phase ◽  
Front Edge ◽  
Strong Magnetic Storm ◽  
Night Side ◽  
Substorm Activity

We analyzed the appearance of two supersubstorms observed during storm on September 07, 2017. Supersubstorms (SSS) are called substorms with SML index < - 2500 nT. The storm on September 07, 2017 is famous event which was studied already in many papers. There were two several geomagnetic storms on 7 and 8 September 2017, which associated with two consecutive solar wind structures: SHEATH with EJECTA and SHEATH with magnetic cloud (MC). Because the first SHEATH have a positive IMF Bz on their front edge the substorm activity absent in this time. The main phase of the first magnetic storm began with arriving the second SHEATH with the strong negative IMF Bz. During this period the first night-side supersubstorm (up to ~ 3500 nT) developed. The second magnetic storm was caused by MC with the negative IMF Bz and the severe night-side supersubstorm (up to ~ 3500 nT) were registered in this time. Thus, during the 7-8 September 2017 storms, two supersubstorms were generated, these supersubstorms caused by the SHEATH and MC impact have demonstrated the global scale distribution.

scholarly journals Variations in Energetic Particle Fluxes around Significant Geomagnetic Storms Observed by the Low-Altitude DEMETER Spacecraft

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 260
Author(s):  
Stefan Gohl ◽  
František Němec ◽  
Michel Parrot
Keyword(s):  
Energetic Particle ◽  
Geomagnetic Storms ◽  
Time Window ◽  
Relativistic Electrons ◽  
Superposed Epoch Analysis ◽  
High Energies ◽  
Low Altitude ◽  
Particle Fluxes ◽  
Solar Wind Parameters ◽  
Epoch Analysis

A superposed epoch analysis is conducted for five geomagnetic storms in the years 2005 and 2006 with the aim to understand energetic particle flux variations as a function of L-shell, energy and time from the Dst minimum. Data measured by the low-altitude DEMETER spacecraft were used for this purpose. The storms were identified by a Dst index below −100 nT, as well as their being isolated events in a seven-day time window. It is shown that they can be categorized into two types. The first type shows significant variations in the energetic particle fluxes around the Dst minimum and increased fluxes at high energies (>1.5 MeV), while the second type only shows increased fluxes around the Dst minimum without the increased fluxes at high energies. The first type of storm is related to more drastic but shorter-lasting changes in the solar wind parameters than the second type. One storm does not fit either category, exhibiting features from both storm types. Additionally, we investigate whether the impenetrable barrier for ultra-relativistic electrons also holds in extreme geomagnetic conditions. For the highest analyzed energies, the obtained barrier L-shells do not go below 2.6, consistent with previous findings.

scholarly journals Protection of power transformers against the effect of magnetic storms

2021 ◽  
Vol 72 (4) ◽  
pp. 249-255
Author(s):  
Daniel Mayer
Keyword(s):  
Power Systems ◽  
High Voltage ◽  
Large Scale ◽  
Geomagnetic Storms ◽  
Power Transformer ◽  
Physical Nature ◽  
Magnetic Storms ◽  
Power Transformers ◽  
Long Distance ◽  
New Device

Abstract In the operation of large-scale power systems for the long-distance transmission of large amounts of electricity, a number of cases have been reported in which anomalies in the Earth’s magnetosphere, referred to as geomagnetic storms, have caused a severe system collapse. Changes in the geomagnetic field cause a semi-saturating phenomenon, in which the high-voltage lines and especially the high-voltage windings of the power transformers of the system are overloaded with current and subsequently also thermally. The present article briefly explains the physical nature of magnetic storms and then describes a new device that either eliminates the possibility of a step-down power transformer accident or significantly reduces its effects on the system. The essence of this device are frequency filters, which are connected in parallel to the high-voltage windings of power transformers. At the beginning of a geomagnetic storm, the frequency filter is automatically connected to the system and is automatically disconnected when it subsides. The operation of frequency filters does not require human intervention, acquisition and operating costs are low and their integration into existing power systems is easy.

scholarly journals Evaluating the relationship between strong geomagnetic storms and electric grid failures in Poland using the geoelectric field as a GIC proxy

2021 ◽  
Author(s):  
Agnieszka Gil-Świderska ◽  
Monika Berendt-Marchel ◽  
Renata Modzelewska ◽  
Szczepan Moskwa ◽  
Agnieszka Siluszyk ◽  
...  
Keyword(s):  
Geomagnetic Storms ◽  
Earth Model ◽  
Geoelectric Field ◽  
Self Organizing Maps ◽  
Superposed Epoch Analysis ◽  
Electrical Grid ◽  
Solar Cycle 24 ◽  
Cycle 24 ◽  
Epoch Analysis ◽  
The Relationship

We study intense geomagnetic storms (Dst < -100nT) during the first half of the solar cycle 24. This type of storm appeared only a few times, mostly associated with southwardly directed heliospheric magnetic field Bz. Using various methods such as self-organizing maps, statistical and superposed epoch analysis, we show that during and right after intense geomagnetic storms, there is growth in the number of transmission line failures. We also examine the temporal changes in the number of failures during 2010-2014 and find that the growing linear tendency of electrical grid failure occurrence is possibly connected with solar activity. We compare these results with the geoelectric field calculated for the region of Poland using a 1-D layered conductivity Earth model.

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