scholarly journals Penetration of the electric fields of the geomagnetic sudden commencement over the globe as observed with the HF Doppler sounders and magnetometers

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Takashi Kikuchi ◽  
Jaroslav Chum ◽  
Ichiro Tomizawa ◽  
Kumiko K. Hashimoto ◽  
Keisuke Hosokawa ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Sudden Commencement ◽  
Ionospheric Currents ◽  
Republic Of China ◽  
F Region ◽  
Electric And Magnetic Fields ◽  
Magnetometer Data ◽  
Electric Potentials ◽  
Geomagnetic Sudden Commencement

AbstractUsing the HF Doppler sounders at middle and low latitudes (Prague, Czech Republic; Tucuman, Argentina; Zhongli, Republic of China, and Sugadaira, Japan), we observed the electric fields of the geomagnetic sudden commencement (SC) propagating near-instantaneously (within 10 s) over the globe. We found that the electric fields of the preliminary impulse (PI) and main impulse (MI) of the SC are in opposite direction to each other and that the PI and MI electric fields are directed from the dusk to dawn and dawn to dusk, respectively, manifesting the nature of the curl-free potential electric field. We further found that the onset and peak of the PI electric field are simultaneous on the day and nightsides (0545, 1250, 1345 MLT) within the resolution of 10 s. With the magnetometer data, we confirmed the near-instantaneous development of the ionospheric currents from high latitudes to the equator and estimated the location of the field-aligned currents that supply the ionospheric currents. The global simultaneity of the electric and magnetic fields does not require the contribution of the magnetohydrodynamic waves in the magnetosphere nor in the F-region ionosphere. The global simultaneity and day–night asymmetry of the electric fields are explained with the ionospheric electric potentials transmitted at the speed of light by the TM0 mode waves in the Earth-ionosphere waveguide.

scholarly journals Equatorial night-time F-region zonal electric fields

1995 ◽  
Vol 13 (8) ◽  
pp. 871-878 ◽  
Author(s):  
S. S. Hari ◽  
B. V. Krishna Murthy
Keyword(s):  
Seasonal Variation ◽  
Electric Field ◽  
Electric Fields ◽  
Night Time ◽  
Equatorial Station ◽  
F Region ◽  
Vertical Drift ◽  
Longitudinal Gradients ◽  
Cycle Maximum ◽  
E Region

Abstract. Night-time F-region vertical electrodynamic drifts at the magnetic equatorial station, Trivandrum are obtained for a period of 2 years, 1989 and 1990 (corresponding to solar cycle maximum epoch), using ionosonde h'F data. The seasonal variation of the vertical drift is found to be associated with the longitudinal gradients of the thermospheric zonal wind. Further, the seasonal variation of the prereversal enhancement of the vertical drift is associated with the time difference between the sunset times of the conjugate E-regions (magnetic field line linked to F-region) which is indicative of the longitudinal gradients of the conductivity (of the E-region). The vertical drifts and the causative zonal electric fields at Trivandrum are compared with those at Jicamarca and F-region zonal electric field models. It is seen that the night-time downward drift (as also the causative westward electric field) at Jicamarca is greater than that at Trivandrum. The prereversal enhancement of the drift is greater at Jicamarca than at Trivandrum during the summer and the equinoxes, whereas during the winter the opposite is the case.

scholarly journals Pemodelan dan Simulasi Medan Listrik pada Jaringan Distribusi 20 kV Double Feeder Konstruksi 3B

2020 ◽  
Vol 4 (3) ◽  
pp. 109-132
Author(s):  
Mohamad Ramdan Febriana Herawan ◽  
Deny Hamdani
Keyword(s):  
Numerical Methods ◽  
Electric Field ◽  
Electric Fields ◽  
Simulation Method ◽  
Average Height ◽  
Charge Simulation Method ◽  
Simulation Experiments ◽  
Surrounding Environment ◽  
Electric And Magnetic Fields ◽  
Maximum Electric Field

ABSTRAKPeralatan listrik yang bertegangan dapat menyebabkan medan listrik di sekitar peralatan listrik, mengetahui besaran nilai medan listrik menjadi hal yang penting, untuk mengetahui paparan medan listrik pada lingkungan sekitar. Metode numerik memainkan peran penting dalam perhitungan medan listrik untuk studi medan listrik yang terkait dengan aplikasi tegangan tinggi. Charge Simulation Method merupakan salah satu metode numerik yang dapat digunakan sebagai pendekatan untuk menghitung distribusi medan listrik dan medan magnet pada penghantar yang bertegangan. Paper ini membahas pemodelan medan listrik di sekitar jaringan distribusi double feeder kontruksi 3B dengan menggunakan Matlab untuk mengetahui jarak ambang batas aman pengaruh medan listrik bagi manusia. Simulasi dilakukan pada setiap fasa konduktor dengan jarak ukuran setiap fasa diatur sesuai kontruksi yang diterapkan pada PLN. Hasil penelitian menunjukan bahwa simulasi menggunakan MATLAB pada distribusi 20 kV double feeder kontruksi 3B, hasil medan listrik maksimal pada ketinggian 1 meter atau pada ketinggian rata-rata manusia, memiliki besaran 1,54 kV/meter. Besaran medan ini lebih kecil dari batas minimal standar WHO dan SNI, sehingga masih masuk batas aman.Kata kunci: medan listrik, charge simulation method, jaringan distribusi, distribusi kontruksi double feeder 3BABSTRACTElectrical equipment can cause an electric field around the equipment, knowing the value of the electric field becomes important, to determine the exposure of the electric field to the surrounding environment. Numerical methods play an important role in the computation of electric fields for the study of electric fields related to high voltage applications. Charge Simulation Method is one of the numerical methods that can be used as an approach to computate the distribution of electric and magnetic fields in a live conductor. This paper discusses the modeling of the electric field around the distribution double feeder 3B construction network using Matlab to determine the safe threshold distance of the influence of the electric field for humans. Simulation experiments are carried out on each phase of the conductor with the distance of each phase adjusted according to the applied construction to PLN. The results showed that the simulation using MATLAB on the distribution of 20 kV double feeder construction of 3B, value of the maximum electric field at an altitude of 1 meter or at an average height of humans, has a magnitude of 1.54 kV / meter. The magnitude of this field is smaller than the minimum WHO and SNI standards, so it is still safe for humans.Keywords: electric field, charge simulation method, distribution network, 3B double feeder construction distribution

scholarly journals Solar and geomagnetic activity effects on mid-latitude F-region electric fields

2008 ◽  
Vol 26 (9) ◽  
pp. 2911-2921 ◽  
Author(s):  
V. V. Kumar ◽  
M. L. Parkinson ◽  
P. L. Dyson ◽  
R. Polglase
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Geomagnetic Activity ◽  
High Speed ◽  
Theoretical Models ◽  
Solar Flux ◽  
Quiet Time ◽  
F Region ◽  
Diurnal Patterns ◽  
Ae Index

Abstract. Diurnal patterns of average F-region ionospheric drift (electric field) and their dependence on solar and geomagnetic activity have been defined using digital ionosonde Doppler measurements recorded at a southern mid-latitude station (Bundoora 145.1° E, 37.7° S geographic, 49° S magnetic). A unique database consisting of 300 907 drift velocities was compiled, mostly using one specific mode of operation throughout 1632 days of a 5-year interval (1999–2003). The velocity magnitudes were generally larger during the night than day, except during the winter months (June–August), when daytime velocities were enhanced. Of all years, the largest drifts tended to occur during the high speed solar wind streams of 2003. Diurnal patterns in the average quiet time (AE<75 nT) meridional drifts (zonal electric field) peaked at up to ~6 m s−1 poleward (0.3 mV m−1 eastward) at 03:30 LST, reversing in direction at ~08:30 LST, and gradually reaching ~10 m s−1 equatorward at ~13:30 LST. The quiet time zonal drifts (meridional electric fields) displayed a clear diurnal pattern with peak eastward flows of ~10 m s−1 (0.52 mV m−1 equatorward) at 09:30 LST and peak westward flows around midnight of ~18 m s−1 (0.95 mV m−1 poleward). As the AE index increased, the westward drifts increased in amplitude and they extended over a greater fraction of the day. The perturbation drifts changed in a similar way with decreasing Dst except the daytime equatorward flows strengthened with increasing AE index, whereas they became weak for Dst<−60 nT. The responses in all velocity components to changing solar flux values were small, but net poleward perturbations during the day were associated with large solar flux values (>192×10−22 W m−2 Hz−1). These results help to more fully quantify the response of the mid-latitude ionosphere to changing solar and geomagnetic conditions, as required to refine empirical and theoretical models of mid-latitude electric fields.

scholarly journals Signatures of 2-day wave in the E-region electric fields and their relationship to winds and ionospheric currents

2009 ◽  
Vol 27 (2) ◽  
pp. 631-638 ◽  
Author(s):  
H. C. Aveiro ◽  
C. M. Denardini ◽  
M. A. Abdu
Keyword(s):  
Electric Fields ◽  
Magnetic Activity ◽  
Ionospheric Currents ◽  
Coherent Scatter ◽  
Meridional Winds ◽  
Magnetometer Data ◽  
E Region ◽  
Dip Equator ◽  
Ionospheric Electric Field ◽  
Coherent Radar

Abstract. We analyze the effects of the 2-day wave activity in the EEJ using one coherent scatter radar and eight magnetometer stations located close to the dip equator. The wavelet analysis of the magnetometer data reveals a 2-day signature in the semidiurnal geomagnetic tide. The E-region zonal background ionospheric electric field, derived from coherent radar measurements, shows 2-day oscillations in agreement with such oscillations in the magnetometers data. An anticorrelation between the amplitude of the tidal periodicites (diurnal and semidiurnal) and that of the 2-day signature is also shown in the electric fields. The results are compared with simultaneous observations of 2-day planetary wave in meridional winds and ionosonde data. Further, our results are discussed based on the analysis of the magnetic activity.

Viscosity of a Polar Gas of Symmetric Top Molecules in Perpendicular Electric and Magnetic Fields

1978 ◽  
Vol 33 (2) ◽  
pp. 225-227 ◽  
Author(s):  
W. E. Köhler
Keyword(s):  
Magnetic Fields ◽  
Kinetic Theory ◽  
Electric Field ◽  
Electric Fields ◽  
Pressure Difference ◽  
Viscosity Coefficients ◽  
Electric And Magnetic Fields ◽  
Symmetric Top Molecules ◽  
Field Influence

A kinetic theory treatment of the influence of perpendicular magnetic and electric fields on the viscosity is given for a polar gas of symmetric top molecules. Expressions for the 9 independent viscosity coefficients are derived. In particular, the electric field influence on the transverse viscomagnetic pressure difference is studied.

scholarly journals Impact of disturbance electric fields in the evening on prereversal vertical drift and spread F developments in the equatorial ionosphere

2018 ◽  
Vol 36 (2) ◽  
pp. 609-620 ◽  
Author(s):  
Mangalathayil A. Abdu ◽  
Paulo A. B. Nogueira ◽  
Angela M. Santos ◽  
Jonas R. de Souza ◽  
Inez S. Batista ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Plasma Bubble ◽  
Large Variability ◽  
Plasma Drift ◽  
F Region ◽  
Vertical Drift ◽  
Spread F ◽  
The Impact ◽  
Magnetic Disturbances

Abstract. Equatorial plasma bubble/spread F irregularity occurrence can present large variability depending upon the intensity of the evening prereversal enhancement in the zonal electric field (PRE), that is, the F region vertical plasma drift, which basically drives the post-sunset irregularity development. Forcing from magnetospheric disturbances is an important source of modification and variability in the PRE vertical drift and of the associated bubble development. Although the roles of magnetospheric disturbance time penetration electric fields in the bubble irregularity development have been studied in the literature, many details regarding the nature of the interaction between the penetration electric fields and the PRE vertical drift still lack our understanding. In this paper we have analyzed data on F layer heights and vertical drifts obtained from digisondes operated in Brazil to investigate the connection between magnetic disturbances occurring during and preceding sunset and the consequent variabilities in the PRE vertical drift and associated equatorial spread F (ESF) development. The impact of the prompt penetration under-shielding eastward electric field and that of the over-shielding, and disturbance dynamo, westward electric field on the evolution of the evening PRE vertical drift and thereby on the ESF development are briefly examined. Keywords. Ionosphere (ionospheric irregularities)

Suppression of runaway of electrons in a Lorentz plasma. II. crossed electric and magnetic fields

1970 ◽  
Vol 4 (3) ◽  
pp. 441-450 ◽  
Author(s):  
Barbara Abraham-Shrauner
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Electric Field ◽  
Electric Fields ◽  
Cyclotron Frequency ◽  
Collision Frequency ◽  
Uniform Electric Field ◽  
Drift Motion ◽  
Electric And Magnetic Fields ◽  
The Magnetic Field

Suppression of runaway of electrons in a weak, uniform electric field in a fully ionized Lorentz plasma by crossed magnetic and electric fields is analysed. A uniform, constant magnetic field parallel to a constant or harmonically time varying electric field does not alter runaway from that in the absence of the magnetic field. For crossed, constant fields the passage to runaway or to free motion as described by constant drift motion and spiral motion about the magnetic field is lengthened in time for strong magnetic fields. The new ‘runaway’ time scale is roughly the ratio of the cyclotron frequency to the collision frequency squared for cyclotron frequencies much greater than the collision frequency. All ‘runaway’ time scales may be given approximately by t2E Teff where tE is the characteristic time of the electric field and Teff is the ffective collision time as estimated from the appropriate component of the electrical conductivity.

BINDING ENERGIES OF HYDROGENIC IMPURITIES ON-CENTER AND OFF-CENTER IN CYLINDRICAL QUANTUM DOTS UNDER ELECTRIC AND MAGNETIC FIELDS

2010 ◽  
Vol 24 (22) ◽  
pp. 4293-4304 ◽  
Author(s):  
SHENG WANG ◽  
GUOZHU WEI ◽  
GUANGYU YI
Keyword(s):  
Quantum Dots ◽  
Binding Energy ◽  
Magnetic Fields ◽  
Electric Field ◽  
Electric Fields ◽  
Effective Radius ◽  
Binding Energies ◽  
Hydrogenic Impurity ◽  
Lateral Confinement ◽  
Electric And Magnetic Fields

The ground-state binding energies of a hydrogenic impurity in cylindrical quantum dots (QDs) subjected to external electric and magnetic fields are investigated using the finite-difference method within the quasi-one-dimensional effective potential model. The QD is modeled by superposing a square-well potential and a strong lateral confinement potential by the combination of a parabolic potential and a changeable magnetic field. We define an effective radius of a cylindrical QD which can describe the strength of the lateral confinement. The effects of the electric fields are less important when the effective radius is very tiny, and the effects are manifested as the effective radius increases. Meanwhile, one finds that the binding energies highly depend on the impurity positions under the applied transverse fields. When the impurity is located at the right half of the cylinder, the electric field pushes the electron to the left side, then the binding energy decreases; when the impurity is located at the left, the binding energy first increases and reaches a peak value, then deceases with the electric field.

scholarly journals Effect of crossed electric and magnetic fields on the helium spectrum

1947 ◽  
Vol 189 (1018) ◽  
pp. 287-295 ◽  
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Electric Fields ◽  
The Other ◽  
Small Field ◽  
Hollow Core ◽  
Electric And Magnetic Fields ◽  
Strong Electric Fields ◽  
Set Up

The authors describe a double canal-ray source, and discuss the general features of greatly improved analyses obtained through its use. A small canal-ray tube is placed along the axis of a hollow core of the magnet, the pole tip itself serving as the cathode with one small central perforation. A similar tube is symmetrically placed in the other core so that the double canal-ray tube provides opposing beams in the region between the pole faces. Here small field plates are set up to establish strong electric fields perpendicular to the canal rays. Light is taken out at right angles to both fields and analyzed by a six-prism glass spectrograph. Displacements and qualitative intensities are tabulated mainly for components of three line groups built round and including λλ 4922, 4472 and 4026 respectively. H = 25,800 oersteds while E = 10-131 kV/cm. Resolved components remain sharp at all field strengths. A few components correspond to Δm = ± 2; but there is no evidence for Δm = ± 3. Intensities of many components are critically dependent upon electric field strength, and in at least one notable case (2 3 P-5 3 G) displacements are similarly dependent. The latter is attributed to repulsion between levels of different m values which nevertheless are forced to cross over each other.

SPECTROSCOPY OF THE HYDROGEN AND ANTI-HYDROGEN ATOMS IN EXTERNAL FIELDS

2004 ◽  
Vol 18 (30) ◽  
pp. 3875-3886 ◽  
Author(s):  
LEONTI LABZOWSKY ◽  
VASILY SHARIPOV ◽  
DMITRI SOLOVYEV ◽  
GÜNTER PLUNIEN ◽  
GERHARD SOFF
Keyword(s):  
Magnetic Fields ◽  
Electric Field ◽  
External Electric Field ◽  
Electric Fields ◽  
Transition Probabilities ◽  
Cpt Violation ◽  
Hydrogen Atoms ◽  
Frequency Distributions ◽  
Electric And Magnetic Fields ◽  
Lorentz Line

The spectroscopical properties of hydrogen (H) and anti-hydrogen [Formula: see text] atoms in external electric and magnetic fields are discussed. This problem became important in connection with the recent experimental success in production of [Formula: see text] atoms. The main features of these experiments are briefly reviewed. The proposals for the search of the CPT violation via comparison of the H and [Formula: see text] spectra are shortly discussed. The spectroscopical differences between H and [Formula: see text] atoms in external magnetic fields and in parallel magnetic and electric fields are described in detail. It is proven that the positions of the maxima of the frequency distributions for transition probabilities in external electric field for H and [Formula: see text] atoms will deviate if the non-resonant corrections to the Lorentz line profile are taken into account.

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