scholarly journals Influence of Geomagnetic Disturbances at Different Times of Day on Locomotor Activity in Zebrafish (Danio Rerio)

2021 ◽  
Vol 3 (4) ◽  
pp. 624-632
Author(s):  
Viacheslav V. Krylov
Keyword(s):  
Locomotor Activity ◽  
Swimming Speed ◽  
Geomagnetic Field ◽  
Geomagnetic Storms ◽  
Biological Effects ◽  
Geomagnetic Variation ◽  
Geomagnetic Disturbances ◽  
Circadian Patterns ◽  
Geomagnetic Perturbations ◽  
Circadian Biorhythms

The influence of magnetic fields and natural geomagnetic storms on biological circadian rhythms are actively studied. This study reveals an impact of local natural perturbations in the geomagnetic field that occurred at different times of the day on circadian patterns of locomotor activity of zebrafish. A decrease in zebrafish swimming speed was observed during the geomagnetic disturbances before or after the fluctuations of diurnal geomagnetic variation. However, if the geomagnetic perturbations coincided with the fluctuations of diurnal geomagnetic variation, the decrease in zebrafish swimming speed was insignificant. This result suggests that the biological effects of geomagnetic disturbances may depend on synchronization with the diurnal geomagnetic variation. It implies that the previously published correlations between geomagnetic activity and medical or biological parameters could result from a disruption in circadian biorhythms.

scholarly journals Measurement of geomagnetically induced current (GIC) around Tokyo, Japan

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Shinichi Watari ◽  
Satoko Nakamura ◽  
Yusuke Ebihara
Keyword(s):  
Solar Flare ◽  
Geomagnetic Storms ◽  
Power Grids ◽  
Geomagnetic Variation ◽  
Induced Current ◽  
Interplanetary Shocks ◽  
Geomagnetic Disturbances ◽  
Geomagnetically Induced Current ◽  
Middle Latitudes ◽  
Sudden Commencements

AbstractWe need a typical method of directly measuring geomagnetically induced current (GIC) to compare data for estimating a potential risk of power grids caused by GIC. Here, we overview GIC measurement systems that have appeared in published papers, note necessary requirements, report on our equipment, and show several examples of our measurements in substations around Tokyo, Japan. Although they are located at middle latitudes, GICs associated with various geomagnetic disturbances are observed, such as storm sudden commencements (SSCs) or sudden impulses (SIs) caused by interplanetary shocks, geomagnetic storms including a storm caused by abrupt southward turning of strong interplanetary magnetic field (IMF) associated with a magnetic cloud, bay disturbances caused by high-latitude aurora activities, and geomagnetic variation caused by a solar flare called the solar flare effect (SFE). All these results suggest that GIC at middle latitudes is sensitive to the magnetospheric current (the magnetopause current, the ring current, and the field-aligned current) and also the ionospheric current.

scholarly journals Development and application of problem-oriented digital twins for magnetic observatories and variation stations

2021 ◽  
pp. 60-71
Author(s):  
Andrei Vorobev ◽  
Vyacheslav Pilipenko ◽  
Gulnara Vorobeva ◽  
Olga Khristodulo
Keyword(s):  
Time Series ◽  
Geomagnetic Field ◽  
Missing Values ◽  
Information Environment ◽  
Small Scale ◽  
Geomagnetic Variation ◽  
Digital Twin ◽  
Digital Twins ◽  
Geomagnetic Data ◽  
Magnetic Station

Introduction: Magnetic stations are one of the main tools for observing the geomagnetic field. However, gaps and anomalies in time series of geomagnetic data, which often exceed 30% of the number of recorded values, negatively affect the effectiveness of the implemented approach and complicate the application of mathematical tools which require that the information signal is continuous. Besides, the missing values ​​add extra uncertainty in computer simulation of dynamic spatial distribution of geomagnetic variations and related parameters. Purpose: To develop a methodology for improving the efficiency of technical means for observing the geomagnetic field. Method: Creation of problem-oriented digital twins of magnetic stations, and their integration into the collection and preprocessing of geomagnetic data, in order to simulate the functioning of their physical prototypes with a certain accuracy. Results: Using Kilpisjärvi magnetic station (Finland) as an example, it is shown that the use of digital twins, whose information environment is made up of geomagnetic data from adjacent stations, can provide the opportunity for reconstruction (retrospective forecast) of geomagnetic variation parameters with a mean square error in the auroral zone of up to 11.5 nT. The integration of problem-oriented digital twins of magnetic stations into the processes of collecting and registering geomagnetic data can provide automatic identification and replacement of missing and abnormal values, increasing, due to the redundancy effect, the fault tolerance of the magnetic station as a data source object. For example, the digital twin of Kilpisjärvi station recovers 99.55% of annual information, and 86.73% of it has an error not exceeding 12 nT. Discussion: Due to the spatial anisotropy of geomagnetic field parameters, the error at the digital twin output will be different in each specific case, depending on the geographic location of the magnetic station, as well as on the number of the surrounding magnetic stations and the distance to them. However, this problem can be minimized by integrating geomagnetic data from satellites into the information environment of the digital twin. Practical relevance: The proposed methodology provides the opportunity for automated diagnostics of time series of geomagnetic data for outliers and anomalies, as well as restoration of missing values and identification of small-scale disturbances.

scholarly journals Geomagnetic field disturbances from the fall of the Lipetsk (june 21, 2018) and Chelyabinsk (february 15, 2013) meteorites

2019 ◽  
Vol 485 (3) ◽  
pp. 361-365
Author(s):  
A. A. Spivak ◽  
S. A. Riabova
Keyword(s):  
Delay Time ◽  
Geomagnetic Field ◽  
Maximum Effect ◽  
Impact Point ◽  
Cosmic Body ◽  
Meteorite Impact ◽  
Geomagnetic Disturbances ◽  
Geophysical Observatory ◽  
Earth’S Atmosphere ◽  
The Impact

Based on the Chelyabinsk (February 13, 2013) and Lipetsk (June 21, 2018) events, disturbances in the Earth's geomagnetic field, which were induced by the fall of these meteorites, were studied. Based on the data provided by geomagnetic observatories of the INTERMAGNET network and the mid-latitude Mikhnevo geophysical observatory (IDG RAS), it was established that the fall of meteorites through the Earth's atmosphere, in general, induces geomagnetic disturbances of up to 5 nT at distances up to 2700 km from the impact point of a cosmic body; the maximum effect is reached with a delay time ranging from ~5 to ~10 min, and the duration of the period of the induced geomagnetic field disturbances varies from ~5 to ~20 min. The estimation dependencies of the amplitude and duration of induced geomagnetic disturbances from a distance from the meteorite impact points are proposed.

scholarly journals Synchronization of geomagnetic and ionospheric disturbances over Kazan station

2017 ◽  
Vol 3 (4) ◽  
pp. 63-73
Author(s):  
Оксана Бархатова ◽  
Oksana Barhatova ◽  
Наталья Косолапова ◽  
Natal'ya Kosolapova ◽  
Николай Бархатов ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Geomagnetic Field ◽  
Critical Frequency ◽  
Ionospheric Disturbances ◽  
Spectral Features ◽  
Quiet Period ◽  
Geomagnetic Disturbances ◽  
Night Time ◽  
Dynamic Spectra ◽  
Solar Wind Parameters

We have analyzed the phenomena which accompany synchronization of night-time ionospheric and geomagnetic disturbances in an ULF range with periods 35–50 min near the mid-latitude station Kazan during a global magnetically quiet period. The comparison between dynamic spectra and wavelet patterns of these disturbances has revealed that spectral features of simultaneous disturbances of the F2-layer critical frequency and H, D, Z geomagnetic field components are similar. By studying spectral features of the F2-layer critical frequency over Kazan and disturbances of the H and D geomagnetic field components at magnetic stations which differ from Kazan in longitude and latitude, we have established that the disturbances considered belong to the class of fast magnetosonic waves. The analysis of solar wind parameters, interplanetary magnetic field (IMF), and values of the auroral index AL in the period under study has shown that this event is associated with IMF Bz component disturbances and occurs during substorm development.

scholarly journals From solar eruption to transformer saturation: the space weather chain

2013 ◽  
Vol 8 (S300) ◽  
pp. 500-501
Author(s):  
Larisa Trichtchenko
Keyword(s):  
Space Weather ◽  
Geomagnetic Field ◽  
Geomagnetic Storms ◽  
Interplanetary Medium ◽  
Practical Importance ◽  
Power Grids ◽  
Geomagnetically Induced Currents ◽  
Large Space ◽  
Weather Events ◽  
Induced Currents

AbstractCoronal mass ejections (CME) and associated interplanetary-propagated solar wind disturbances are the established causes of the geomagnetic storms which, in turn, create the most hazardous impacts on power grids. These impacts are due to the large geomagnetically induced currents (GIC) associated with variations of geomagnetic field during storms, which, flowing through the transformer windings, cause extra magnetisation. That can lead to transformer saturation and, in extreme cases, can result in power blackouts. Thus, it is of practical importance to study the solar causes of the large space weather events. This paper presents the example of the space weather chain for the event of 5-6 November 2001 and a table providing complete overview of the largest solar events during solar cycle 23 with their subsequent effects on interplanetary medium and on the ground. This compact overview can be used as guidance for investigations of the solar causes and their predictions, which has a practical importance in everyday life.

Possible Influence of the Solar Eclipse on the Global Geomagnetic Field

2017 ◽  
Vol 13 (S335) ◽  
pp. 167-170
Author(s):  
Jung-Hee Kim ◽  
Heon-Young Chang
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Solar Eclipse ◽  
Geomagnetic Field ◽  
Geomagnetic Observatory ◽  
Geomagnetic Disturbances ◽  
Solar Eclipses ◽  
A Site

AbstractWe investigate the geomagnetic field variations recorded by INTERMAGNET geomagnetic observatories. We confirm that the effect of solar eclipse can be seen over an interval of 180 minutes centered at the time of maximum eclipse on a site of a geomagnetic observatory. It is found that the effect of the solar eclipse on the geomagnetic field becomes conspicuous as the magnitude of a solar eclipse becomes larger. The effect of solar eclipses is more evident in the second half of the path of Moon’s shadow. We also find that the effect can be overwhelmed, more sensitively by geomagnetic disturbances than by solar activity of solar cycle.

scholarly journals The response of the H geocorona between 3 and 8 <i>R</i><sub>e</sub> to geomagnetic disturbances studied using TWINS stereo Lyman-<i>α</i> data

2017 ◽  
Vol 35 (1) ◽  
pp. 171-179 ◽  
Author(s):  
Jochen H. Zoennchen ◽  
Uwe Nass ◽  
Hans J. Fahr ◽  
Jerry Goldstein
Keyword(s):  
Solar Minimum ◽  
Column Density ◽  
Geomagnetic Storms ◽  
Neutral Hydrogen ◽  
Wind Pressure ◽  
Time Shift ◽  
Line Center ◽  
Storm Event ◽  
Geomagnetic Disturbances ◽  
Pressure Peak

Abstract. Circumterrestrial Lyman-α column brightness observations from 3–8 Earth radii (Re) have been used to study temporal density variations in the exospheric neutral hydrogen as response to geomagnetic disturbances of different strength, i.e., Dst peak values between −26 and −147 nT. The data used were measured by the two Lyman-α detectors (LAD1/2) onboard both TWINS satellites between the solar minimum of 2008 and near the solar maximum of 2013. The solar Lyman-α flux at 121.6 nm is resonantly scattered near line center by exospheric H atoms and measured by the TWINS LADs. Along a line of sight (LOS), the scattered LOS-column intensity is proportional to the LOS H column density, assuming optically thin conditions above 3 Re. In the case of the eight analyzed geomagnetic storms we found a significant increase in the exospheric Lyman-α flux between 9 and 23 % (equal to the same increase in H column density ΔnH) compared to the undisturbed case short before the storm event. Even weak geomagnetic storms (e.g., Dst peak values  ≥  −41 nT) under solar minimum conditions show increases up to 23 % of the exospheric H densities. The strong H density increase in the observed outer exosphere is also a sign of an enhanced H escape flux during storms. For the majority of the storms we found an average time shift of about 11 h between the time when the first significant dynamic solar wind pressure peak (pSW) hits the Earth and the time when the exospheric Lyman-α flux variation reaches its maximum. The results show that the (relative) exospheric density reaction of ΔnH have a tendency to decrease with increasing peak values of Dst index or the Kp index daily sum. Nevertheless, a simple linear correlation between ΔnH and these two geomagnetic indices does not seem to exist. In contrast, when recovering from the peak back to the undisturbed case, the Kp index daily sum and the ΔnH essentially show the same temporal recovery.

scholarly journals Magnetic local time dependence of geomagnetic disturbances contributing to the AU and AL indices

2011 ◽  
Vol 29 (4) ◽  
pp. 673-678 ◽  
Author(s):  
S. Tomita ◽  
M. Nosé ◽  
T. Iyemori ◽  
H. Toh ◽  
M. Takeda ◽  
...  
Keyword(s):  
Local Time ◽  
Geomagnetic Field ◽  
Field Data ◽  
Geomagnetic Latitude ◽  
Magnetic Activity ◽  
Auroral Zone ◽  
Magnetic Local Time ◽  
Geomagnetic Disturbances ◽  
Current Systems ◽  
Local Time Dependence

Abstract. The Auroral Electrojet (AE) indices, which are composed of four indices (AU, AL, AE, and AO), are calculated from the geomagnetic field data obtained at 12 geomagnetic observatories that are located in geomagnetic latitude (GMLAT) of 61.7°–70°. The indices have been widely used to study magnetic activity in the auroral zone. In the present study, we examine magnetic local time (MLT) dependence of geomagnetic field variations contributing to the AU and AL indices. We use 1-min geomagnetic field data obtained in 2003. It is found that both AU and AL indices have two ranges of MLT (AU: 15:00–22:00 MLT, ~06:00 MLT; and AL: ~02:00 MLT, 09:00–12:00 MLT) contributing to the index during quiet periods and one MLT range (AU: 15:00–20:00 MLT, and AL: 00:00–06:00 MLT) during disturbed periods. These results are interpreted in terms of various ionospheric current systems, such as, Sqp, Sq, and DP2.

scholarly journals Observations of the F-region ionospheric irregularities in the South American sector during the October 2003 "Halloween Storms"

2009 ◽  
Vol 27 (12) ◽  
pp. 4463-4477 ◽  
Author(s):  
Y. Sahai ◽  
F. Becker-Guedes ◽  
P. R. Fagundes ◽  
A. J. de Abreu ◽  
R. de Jesus ◽  
...  
Keyword(s):  
Geomagnetic Storms ◽  
Ionospheric Irregularities ◽  
South American ◽  
The South ◽  
Geomagnetic Disturbances ◽  
Plasma Bubbles ◽  
F Region ◽  
A Chain ◽  
Ionospheric Sounding ◽  
Gps Observations

Abstract. The response of the ionospheric F-region in the South American sector during the super geomagnetic storms on 29 and 30 October 2003 is studied in the present investigation. In this paper, we present ionospheric sounding observations during the period 29–31 October 2003 obtained at Palmas (a near equatorial location) and Sao Jose dos Campos (a location under the southern crest of the equatorial ionospheric anomaly), Brazil, along with observations during the period 27–31 October 2003 from a chain of GPS stations covering the South American sector from Imperatriz, Brazil, to Rio Grande, Argentina. Also, complementary observations that include sequences of all-sky images of the OI 777.4 and 630.0 nm emissions observed at El Leoncito, Argentina, on the nights of 28–29 (geomagnetically quiet night) and 29–30 (geomagnetically disturbed night) October 2003, and ion densities observed in the South American sector by the DMSP F13, F14 and F15 satellites orbiting at about 800 km on 29 and 30 October 2003 are presented. In addition, global TEC maps derived from GPS observations collected from the global GPS network of International GPS Service (IGS) are presented, showing widespread and drastic TEC changes during the different phases of the geomagnetic disturbances. The observations indicate that the equatorial ionospheric irregularities or plasma bubbles extend to the Argentinean station Rawson (geom. Lat. 33.1° S) and map at the magnetic equator at an altitude of about 2500 km.

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