scholarly journals Numerical modeling of the equatorial electrojet UT-variation on the basis of the model GSM TIP

2007 ◽  
Vol 5 ◽  
pp. 385-392 ◽  
Author(s):  
M. V. Klimenko ◽  
V. V. Klimenko ◽  
V. V. Bryukhanov
Keyword(s):  
Numerical Modeling ◽  
Electric Fields ◽  
Surface Density ◽  
Three Dimensional ◽  
Equatorial Electrojet ◽  
Near Earth Space ◽  
Peak Intensity ◽  
Dimensional Equation ◽  
Diurnal Behavior ◽  
Field Lines

Abstract. In the presented work the results of numerical modeling of the UT-variation of the equatorial electrojet, executed on the basis of the model GSM TIP are presented, taking into account the dynamo electric fields generated by thermospheric winds in a current-carrying layer of the ionosphere at heights 80–175 km above a surface of the Earth. To the Global Self-consistent Model of the Thermosphere, Ionosphere and Protonosphere (GSM TIP), developed in WD IZMIRAN, a new block for the calculation of electric fields in the ionosphere has been added. In this block the solution of the three-dimensional equation describing the conservation law of the full current in the Earth's ionosphere is reduced to the solution of the two-dimensional equation by integration along geomagnetic field lines. Calculations of parameters of the near-Earth space plasmas have been executed for quiet equinoctial conditions on 22 March 1987 during the minimum of solar activity. It has been shown, that there is a distinct semidiurnal harmonic in the diurnal behavior of the linear density of the equatorial electrojet with maxima at 23:00 UT and 15:00 UT, as well as with minima at 06:00 UT and 20:00 UT. The greatest and smallest values of the peak intensity of the equatorial electrojet with respect to the diurnal behavior can differ by a factor of two. The longitudinal extent of the area of the equatorial electrojet does hardly show any UT-variation, but the greatest longitudinal extent is at 06 UT. With the growth of the peak intensity of the equatorial electrojet its latitudinal extent also increases (on ~5–10°) a little. At the same time the equatorial electrojet in the maxima of intensity has approximately an identical width, whereas in the minima the electrojet is narrow in the morning and wide in the afternoon. As for the surface density of the equatorial electrojet, its UT-variation is much weaker and equals ~1–3 A/km2 and the peak intensity is equal ~15–20 A/km2. The latitudinal extent of the surface density of the equatorial electrojet is maximal at 23:00 UT and 15:00 UT and minimal at 06:00 UT and 20:00 UT.

Numerical modeling of cathode-directed streamers branching in strong electric fields

2016 ◽  
Author(s):  
Белогловский ◽  
Andrey Beloglovskiy ◽  
Федорова ◽  
A. Fedorova
Keyword(s):  
Numerical Modeling ◽  
Numerical Model ◽  
Electric Fields ◽  
Strong Field ◽  
Strong Electric Field ◽  
Three Dimensional ◽  
Strong Electric Fields ◽  
Electron Avalanches ◽  
Discharge Gap ◽  
Positive Streamer

A research of conditions of the branching of positive streamer in air in a strong electric field by the use a three-dimensional numerical model is presented. This model is based on the assumption that the development of large electron avalanches in the strong field in front of the streamer head leads to branching. Tendency for branching has been observed, if the ratio of the diameters of the streamer heads to the distance between them is not greater than 0.55. If this ratio is more than 0,55, merger of originally formed streamer heads has been observed, and then only one streamer develops in the discharge gap.

Proton acceleration in three-dimensional non-null magnetic reconnection

2016 ◽  
Vol 82 (5) ◽  
Author(s):  
Z. Akbari ◽  
M. Hosseinpour ◽  
M. A. Mohammadi
Keyword(s):  
Magnetic Field ◽  
Energy Distribution ◽  
Magnetic Reconnection ◽  
Electric Fields ◽  
Three Dimensional ◽  
Null Point ◽  
Proton Acceleration ◽  
Electric And Magnetic Fields ◽  
Field Lines ◽  
The Magnetic Field

In a three-dimensional non-null magnetic reconnection, the process of magnetic reconnection takes place in the absence of a null point where the magnetic field vanishes. By randomly injecting a population of 10 000 protons, the trajectory and energy distribution of accelerated protons are investigated in the presence of magnetic and electric fields of a particular model of non-null magnetic reconnection with the typical parameters for the solar corona. The results show that protons are accelerated along the magnetic field lines away from the non-null point only at azimuthal angles where the magnitude of the electric field is strongest and therefore particles obtain kinetic energies of the order of thousands of MeV and even higher. Moreover, the energy distribution of the population depends strongly on the amplitude of the electric and magnetic fields. Comparison shows that a non-null magnetic reconnection is more efficient in accelerating protons to very high GeV energies than a null-point reconnection.

Novel three-dimensional multi-objective numerical modeling for hot strip tandem rolling

2021 ◽  
Author(s):  
Lianjie Li ◽  
Jianxin Li ◽  
Haibo Xie ◽  
Hongqiang Liu ◽  
Li Sun ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Three Dimensional ◽  
Multi Objective ◽  
Hot Strip

scholarly journals In-situ measurements of wave electric fields in the equatorial electrojet

1982 ◽  
Vol 9 (6) ◽  
pp. 688-691 ◽  
Author(s):  
R. F. Pfaff ◽  
M. C. Kelley ◽  
B. G. Fejer ◽  
N. C. Maynard ◽  
K. D. Baker
Keyword(s):  
Electric Fields ◽  
Equatorial Electrojet ◽  
In Situ Measurements

scholarly journals The Formation of a Cavity in a 3D Flux Rope

2013 ◽  
Vol 8 (S300) ◽  
pp. 147-150 ◽  
Author(s):  
Donald Schmit ◽  
Sarah Gibson
Keyword(s):  
Ad Hoc ◽  
Numerical Models ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Flux Rope ◽  
Multiple Structures ◽  
Field Lines ◽  
Hydrostatic Balance ◽  
Distinct Field ◽  
Three Dimensional Space

AbstractThere are currently no three dimensional numerical models which describe the magnetic and energetic formation of prominences self-consistently. Consequently, there has not been significant progress made in understanding the connection between the dense prominence plasma and the coronal cavity. We have taken an ad-hoc approach to understanding the energetic implications of the magnetic models of prominence structure. We extract one dimensional magnetic field lines from a 3D MHD model of a flux rope and solve for hydrostatic balance along these field lines incorporating field-aligned thermal conduction, uniform heating, and radiative losses. The 1D hydrostatic solutions for density and temperature are then mapped back into three dimensional space, which allows us to consider the projection of multiple structures. We find that the 3D flux rope is composed of several distinct field line types. A majority of the flux rope interior field lines are twisted but not dipped. These field lines are density-reduced relative to unsheared arcade field lines. We suggest the cavity may form along these short interior field lines which are surrounded by a sheath of dipped field lines. This geometric arrangement would create a cavity on top of a prominence, but the two structures would not share field lines or plasma.

Three-Dimensional Numerical Modeling of Convective Heat Transfer During Shallow-Depth Forced-Air Drying of Brown Rice Grains

2015 ◽  
Vol 33 (11) ◽  
pp. 1350-1359 ◽  
Author(s):  
Jonathan H. Perez ◽  
Fumina Tanaka ◽  
Fumihiko Tanaka ◽  
Daisuke Hamanaka ◽  
Toshitaka Uchino
Keyword(s):  
Heat Transfer ◽  
Numerical Modeling ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Three Dimensional ◽  
Brown Rice ◽  
Shallow Depth ◽  
Air Drying ◽  
Rice Grains ◽  
Forced Air
Sign in / Sign up

Export Citation Format

Share Document