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 Variations of energetic particle fluxes after interplanetary shock arrivals and around significant geomagnetic storms observed by low altitude spacecraft

2021 ◽  
Author(s):  
Stefan Gohl ◽  
František Němec ◽  
Michel Parrot
Keyword(s):  
Energetic Particle ◽  
Geomagnetic Storms ◽  
Radiation Detector ◽  
Interplanetary Shock ◽  
X Rays ◽  
Loss Cone ◽  
Low Altitude ◽  
Particle Fluxes ◽  
Synchronous Orbit ◽  
The Times

<p>We analyze variations of energetic particle fluxes measured by low altitude spacecraft after interplanetary shock arrivals and around the times of significant geomagnetic storms. Data from two different spacecraft and energetic particle detectors are used and compared. First, we use data measured by the energetic particle detector (IDP) onboard the Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) spacecraft. The spacecraft operated between 2004 and 2010 on a circular Sun-synchronous orbit at an altitude of initially 710 km, which was decreased to 660 km in December 2005. The IDP instrument measured electron flux close to the loss cone at energies between about 70 keV and 2.3 MeV (128 energy channels). Second, we use data measured by the Space Application of Timepix Radiation Monitor (SATRAM) onboard the Proba-V satellite operating since May 2013 on a circular Sun-synchronous orbit at an altitude of 820 km. The semi-conductor based pixelated radiation detector called Timepix is capable of detecting all charged particles and X-rays with sufficiently high energies. Electron energies higher than about 2 MeV and proton energies higher than about 20 MeV are detected. We identify the times of interplanetary shock arrivals and significant (Dst < –100 nT) geomagnetic storms during the mission durations. Then we perform a superposed epoch analysis to reveal characteristic particle flux variations around these times at different energies and L-shells. Although the used satellite missions do not overlap in time, we aim to compare the revealed flux variation signatures between these two independent data sets.</p>

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.

Drifting Electron Holes Occurring During Geomagnetically Quiet Times: BD-IES Observations

2020 ◽  
Author(s):  
Zhi-Yang Liu ◽  
Qiu-Gang Zong ◽  
Hong Zou
Keyword(s):  
Quiet Time ◽  
Drift Motion ◽  
Superposed Epoch Analysis ◽  
Bursty Bulk Flow ◽  
Magnetospheric Multiscale ◽  
Substorm Activity ◽  
Ground Magnetic ◽  
Solar Wind Parameters ◽  
Epoch Analysis ◽  
Electron Holes

&lt;p&gt;Drifting electron holes (DEHs), manifesting as sudden but mild dropout in electron flux, are a common phenomenon seen in the Earth's magnetosphere. It manifests the change of the state of the magnetosphere. However, previous studies primarily focus on DEHs during geomagnetically active time (e.g., substorm). Not until recently have quiet time DEHs been reported. In this paper, we present a systematic study on the quiet time DEHs. BeiDa Imaging Electron Spectrometer (BD-IES) measurements from 2015 to 2017 are investigated. Twenty-two DEH events are identified. The DEHs cover the whole energy range of BD-IES (50&amp;#8211;600 keV). Generally, the DEHs are positively dispersive with respect to energy. Time-of-flight analysis suggests the dispersion results from electron drift motion and gives the location where the DEHs originated from. Statistics reveal the DEHs primarily originated from the postmidnight magnetosphere. In addition, superposed epoch analysis applied to geomagnetic indices and solar wind parameters indicates these DEH events occurred during geomagnetically quiet time. No storm or substorm activity could be identified. However, an investigation into nightside midlatitude ground magnetic records suggests these quiet time DEHs were accompanied by Pi2 pulsations. The DEH-Pi2 connection indicates a possible DEH-bursty bulk flow (BBF) connection, since nightside midlatitude Pi2 activity is generally attributed to magnetotail BBFs. This connection is also supported by a case study of coordinated magnetotail observations from Magnetospheric Multiscale spacecraft. Therefore, we suggest the quiet time DEHs could be caused by magnetotail BBFs, similar to the substorm time DEHs.&lt;/p&gt;

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

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;

Association of chorus waves and source/seed electrons with the enhancement of relativistic electrons in the outer Van Allen belt

2020 ◽  
Author(s):  
Afroditi Nasi ◽  
Ioannis A. Daglis ◽  
Christos Katsavrias ◽  
Wen Li
Keyword(s):  
Relativistic Electron ◽  
Radiation Belt ◽  
Geomagnetic Disturbance ◽  
Relativistic Electrons ◽  
Outer Radiation Belt ◽  
Inner Magnetosphere ◽  
Superposed Epoch Analysis ◽  
Chorus Waves ◽  
Substorm Activity ◽  
Epoch Analysis

&lt;p&gt;Local acceleration driven by whistler-mode chorus waves is fundamentally important for the acceleration of seed electrons in the outer radiation belt to relativistic energies. &amp;#932;his mechanism strongly depends on substorm activity and on the source electron population injected by the substorms into the inner magnetosphere. In our work we use Van Allen Probes data to investigate the features of source electrons, seed electrons and chorus waves for events of enhancement versus events of depletion of relativistic electrons in the outer Van Allen belt. To that end we calculate the electron phase space density (PSD) for five values of the first adiabatic invariant corresponding to source and seed electrons, and we perform a superposed epoch analysis of 28 geomagnetic disturbance events, out of which, 20 result in enhancement and 8 in depletion of relativistic electron PSD. Our results indicate that events resulting in significant enhancement of relativistic electron PSD in the outer radiation belt are characterized by statistically stronger and more prolonged storm and substorm activity, leading to more efficient injections of source but mostly seed electrons to the inner magnetosphere, and also to more pronounced and long-lasting chorus and Pc5 wave activity. The effect of these parameters in the acceleration of electrons seems to be determined by the abundance of seed electrons at the region of L*=4-5.&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 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.

Sign in / Sign up

Export Citation Format

Share Document