scholarly journals Katz Fractal Dimension of Geoelectric Field during Severe Geomagnetic Storms

Entropy ◽  
2021 ◽  
Vol 23 (11) ◽  
pp. 1531
Author(s):  
Agnieszka Gil ◽  
Vasile Glavan ◽  
Anna Wawrzaszek ◽  
Renata Modzelewska ◽  
Lukasz Tomasik
Keyword(s):  
Time Series ◽  
Fractal Dimension ◽  
Geomagnetic Storms ◽  
Field Measurements ◽  
Earth Model ◽  
Geoelectric Field ◽  
The Earth ◽  
Activity Cycles ◽  
First Time ◽  
Solar Activity Cycles

We are concerned with the time series resulting from the computed local horizontal geoelectric field, obtained with the aid of a 1-D layered Earth model based on local geomagnetic field measurements, for the full solar magnetic cycle of 1996–2019, covering the two consecutive solar activity cycles 23 and 24. To our best knowledge, for the first time, the roughness of severe geomagnetic storms is considered by using a monofractal time series analysis of the Earth electric field. We show that during severe geomagnetic storms the Katz fractal dimension of the geoelectric field grows rapidly.

scholarly journals Distribution of tensor anisotropy of cosmic rays near the neutral current sheet

2017 ◽  
Vol 3 (2) ◽  
pp. 18-21
Author(s):  
Петр Гололобов ◽  
Peter Gololobov ◽  
Прокопий Кривошапкин ◽  
Prokopy Krivoshapkin ◽  
Гермоген Крымский ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Temporal Change ◽  
Neutral Current ◽  
Ground Level ◽  
Survey Method ◽  
Time Profiles ◽  
Activity Cycles ◽  
First Time ◽  
Solar Activity Cycles ◽  
Ground Level Enhancements

We analyze time profiles of isotropic intensity, components of vector and tensor anisotropies of cos-mic rays (CR) when Earth crosses the neutral sheet of the interplanetary magnetic field (IMF) in solar activity cycles 23–24. The moments of the crossings are de-termined from Wilcox Observatory synoptic charts and IMF data. Periods of Forbush decreases and ground level enhancements are excluded from the analysis. The events are analyzed for the epochs of positive and negative signs of the Sun’s general magnetic field. During each epoch, the crossings from the positive sector to the negative one and vice versa are separated. In total, 213 crossing events have been selected. The first two spherical harmonics of the angular CR-distribution are obtained using the global survey method. In each case, the average number of stations is equal to 32. The analysis shows that the temporal change of the isotropic component is caused by a magnetic mirror. For the first time, the zonal harmonics are reliably distinguished, and the existence of the antisymmetric diurnal CR-variation in a low energy range, which is oriented along IMF, is recognized. We compare our results with those obtained earlier.

scholarly journals Complexity-Based Decoding of the Coupling Among Heart Rate Variability (HRV) and Walking Path

2020 ◽  
Vol 11 ◽  
Author(s):  
Shahul Mujib Kamal ◽  
Mohammad Hossein Babini ◽  
Ondrej Krejcar ◽  
Hamidreza Namazi
Keyword(s):  
Heart Rate ◽  
Time Series ◽  
Heart Rate Variability ◽  
Fractal Dimension ◽  
Daily Life ◽  
Fractal Theory ◽  
Sample Entropy ◽  
Physiological Signals ◽  
Everyday Activity ◽  
First Time

Walking is an everyday activity in our daily life. Because walking affects heart rate variability, in this research, for the first time, we analyzed the coupling among the alterations of the complexity of walking paths and heart rate. We benefited from the fractal theory and sample entropy to evaluate the influence of the complexity of paths on the complexity of heart rate variability (HRV) during walking. We calculated the fractal exponent and sample entropy of the R-R time series for nine participants who walked on four paths with various complexities. The findings showed a strong coupling among the alterations of fractal dimension (an indicator of complexity) of HRV and the walking paths. Besides, the result of the analysis of sample entropy also verified the obtained results from the fractal analysis. In further studies, we can analyze the coupling among the alterations of the complexities of other physiological signals and walking paths.

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

<p>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  B<sub>z</sub> . 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.</p>

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.

scholarly journals Distribution of tensor anisotropy of cosmic rays near the neutral current sheet

2017 ◽  
Vol 3 (2) ◽  
pp. 16-19
Author(s):  
Петр Гололобов ◽  
Peter Gololobov ◽  
Прокопий Кривошапкин ◽  
Prokopy Krivoshapkin ◽  
Гермоген Крымский ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Temporal Change ◽  
Neutral Current ◽  
Ground Level ◽  
Survey Method ◽  
Time Profiles ◽  
Activity Cycles ◽  
First Time ◽  
Solar Activity Cycles ◽  
Ground Level Enhancements

We analyze time profiles of isotropic intensity, components of vector and tensor anisotropies of cos-mic rays (CR) when Earth crosses the neutral sheet of the interplanetary magnetic field (IMF) in solar activity cycles 23–24. The moments of the crossings are de-termined from Wilcox Observatory synoptic charts and IMF data. Periods of Forbush decreases and ground level enhancements are excluded from the analysis. The events are analyzed for the epochs of positive and negative signs of the Sun’s general magnetic field. During each epoch, the crossings from the positive sector to the negative one and vice versa are separated. In total, 213 crossing events have been selected. The first two spherical harmonics of the angular CR-distribution are obtained using the global survey method. In each case, the average number of stations is equal to 32. The analysis shows that the temporal change of the isotropic component is caused by a magnetic mirror. For the first time, the zonal harmonics are reliably distinguished, and the existence of the antisymmetric diurnal CR-variation in a low energy range, which is oriented along IMF, is recognized. We compare our results with those obtained earlier.

scholarly journals Shape of solar cycles and mid-term solar activity oscillations

2020 ◽  
Vol 497 (4) ◽  
pp. 4376-4383
Author(s):  
D D Sokoloff ◽  
A S Shibalova ◽  
V N Obridko ◽  
V V Pipin
Keyword(s):  
Time Series ◽  
Solar Activity ◽  
Magnetic Dipole ◽  
Solar Interior ◽  
Solar Dynamo ◽  
Dynamo Model ◽  
Solar Cycles ◽  
Physical Explanation ◽  
Activity Cycles ◽  
Solar Activity Cycles

ABSTRACT The evolution of solar activity comprises, apart from the well-known 11-year cycle, various temporal scales ranging from months up to the secondary cycles known as mid-term oscillations. Its nature deserves a physical explanation. In this work, we have considered the 5–6 year oscillations as derived both from sunspots and solar magnetic dipole time series. Using a solar dynamo model, we have deduced that these variations may be a manifestation of dynamo non-linearities and the non-harmonic shape of the solar activity cycles. We have concluded that the observed mid-term oscillations are related to the non-linear saturation of dynamo processes in the solar interior.

Alexander and the Mongols

1979 ◽  
Vol 111 (2) ◽  
pp. 123-136 ◽  
Author(s):  
John Andrew Boyle
Keyword(s):  
Eighth Century ◽  
Alexander The Great ◽  
The Caucasus ◽  
The North ◽  
The Earth ◽  
Four Corners ◽  
Book Of Genesis ◽  
First Time

The association of Alexander the Great with the Mongols begins with the identification of the latter with the peoples of Gog and Magog. The evolution of this legend, which has its origin in the Book of Genesis, is curious in the extreme. In Genesis Magog is mentioned as one of the sons of Japhet, his name occurring between those of Gomer and Madai. Since Madai is clearly intended as the eponym of the Medes and Gomer has been located in Cappadocia and Phrygia it has been plausibly suggested that Magog at this stage corresponded to the territory in between, i.e. the region immediately south of the Caucasus in Eastern and Northern Armenia. In Ezekiel we hear for the first time of Gog “of the land of Magog”, who will come from his place out of the uttermost parts of the north, he and many peoples with him, “all of them riding on horses, a great company and a mighty army.” It will be seen that the “land of Magog” can no longer be located south of the Caucasus, and indeed Ezekiel's prophecy of the invasion of Gog has been interpreted as an echo of the invasions of the Cimmerians, who came southwards from the steppes through the Darial pass towards the end of the eighth century B.C.; or more probably of the invasion of the Scythians which took place in the following century by way of Darband. Finally we are told in Revelation that “when the thousand years are finished, Satan shall be loosed out of his prison, and shall come forth to deceive the nations which are in the four corners of the earth, Gog and Magog, to gather them together to the war; the number of whom is as the sand of the sea”.

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