Convection Electric Field Research Articles

Electron Dynamics and Whistler‐Mode Waves Inside the Short Large‐Amplitude Magnetic Field Structures

AbstractWe investigate the electron dynamics and generation of whistler‐mode waves inside a short large‐amplitude magnetic structure (SLAMS) based on Magnetospheric Multiscale Satellite observations and test particle simulations. The buildup of energetic reflected ions caused by the SLAMS's intense magnetic fields favors the resonance condition of solar wind ions of ion‐ion non‐resonant mode. This might further steepen the SLAMS, leading to the Betatron acceleration of electrons and generating the whistler‐mode waves locally ahead of the peak of the magnetic field. In regions behind the peaked magnetic field, electrons are decelerated by the convection electric field during gradient drift and the whistler‐mode waves are rapidly decayed. Our study provides new insights into electron acceleration and the generation of whistler‐mode waves near the quasi‐parallel shock.

The Influence of Solar Irradiation and Solar Wind Conditions on Heavy Ion Escape from Mars

AbstractWe apply a recently proposed method to estimate heavy ion escape from Mars. The method combines in situ observations with a hybrid plasma model, which treats ions as particles and electrons as a fluid. With this method, we investigate how solar upstream conditions, including solar extreme ultraviolet (EUV) radiation, solar wind dynamic pressure, and interplanetary magnetic field (IMF) strength and cone angle, affect the heavy ion loss. The results indicate that the heavy ion escape rate is greater in high EUV conditions. The escape rate increases with increasing solar wind dynamic pressure, and decreases as the IMF strength increases. The ion escape rate is highest when the solar wind is parallel to the IMF and lowest when they are perpendicular. The plume escape rate decreases when the solar wind convective electric field increases.

Magnetohydrodynamic Shocks Revisited: Magnetically Constraining the Upstream Solar Wind Condition

Magnetohydrodynamic (MHD) shocks are commonly found in various space and astrophysical systems. One often encounters the problem that only the magnetic field data are available when studying interplanetary shocks and planetary bow shocks in the solar system, and not the plasma data due to instrumental and/or telemetry limitations. We aim to reveal the mathematical structure of the MHD Rankine–Hugoniot relation under the condition that magnetic field changes across the shock are known, which can be devised into a diagnosis tool to constrain the shock parameters. The perturbative solution is already known for the Rankine–Hugoniot equation. The solution is combined with the condition of the de Hoffmann–Teller frame for the vanishing convective electric field, and we obtain a two-dimensional matrix equation for the density jump and the Alfvén Mach number. The lesson is that the shock parameters (density jump and Alfvén Mach number) are analytically obtained by inverting the MHD Rankine–Hugoniot equation under the condition that the plasma beta is either a priori set or known. Further numerical studies indicate that the presented shock jump estimation works particularly well for quasi-perpendicular shocks. Moreover, a test case with the Earth bow shock crossing data supports our theoretical development. The presented method opens the door to determining or constraining the shock parameters even if the data are limited to the magnetic field only.

Tianwen-1 and MAVEN observations of Martian oxygen ion plumes

There is a significant Martian ion escape channel called the “plume”. Due to the lack of multi-point, high-resolution field and particle detections, the energization mechanism and source region identification of ion plumes by in situ measurements remain unclear. China's first Mars exploration mission, Tianwen-1, provides us an opportunity to study ion escape owing to the high altitude of its apoapsis (∼3 RM, RM is Mars radius). In this study, we take advantage of the joint observations of Tianwen-1 and Mars Atmosphere and Volatile EvolutioN (MAVEN) to study oxygen ion plumes. Our statistical results confirm the convection electric field acceleration as the energization mechanism of plume ions (up to >15 keV) in a more direct way than ever before. Our estimation suggests that most ion plumes originate from middle and low MSE (Mars Solar Electric) latitude of the northern dayside Martian ionosphere. This work improves our understanding of the pick-up process of the Martian escaping ions.

Spatio‐Temporal Characteristics of IPDP‐Type EMIC Waves on April 19, 2017: Implications for Loss of Relativistic Electrons in the Outer Belt

AbstractTo understand the mechanism of the increased frequency of intervals of pulsations of diminishing periods (IPDPs), we analyzed IPDP‐type electromagnetic ion cyclotron (EMIC) waves that occurred on 19 April 2017, using ground and satellite observations. Observations by low‐altitude satellites and ground‐based magnetometers indicate that the increased IPDP frequency is caused by an inward (i.e., Earthward) shift of the EMIC wave source region. The EMIC wave source region moves inward along the mid‐latitude trough, which we used as a proxy for the plasmapause location. A statistical analysis shows that increases in the IPDP frequency showed a positive correlation with polar cap potentials. These results suggest an enhanced convection electric field causes an inward shift of the source region. The inward shift of the source region allows EMIC waves to scatter relativistic electrons over a wide range of radial distances during the IPDP event. This mechanism suggests that IPDP‐type EMIC waves are more likely to scatter relativistic electrons than other EMIC waves. We also show that the decreased phase‐space density of relativistic electrons in the outer radiation belt is consistent with the extent of the source region and the resonant energy of EMIC waves, implying a possible contribution of EMIC waves to outer radiation belt loss during the main phase of geomagnetic storms.

A dataset of field-aligned Poynting flux in the dayside polar cap of the northern hemisphere during 2014-2016

The transport of electromagnetic energy in the polar upper atmosphere and its spatial and temporal distribution are current hot issues and important topics for studying the polar upper atmospheric environment and space weather forecasting models. Researchers usually adopted the observations from low-altitude polar-orbiting satellites to estimate the magnitude and direction of electromagnetic energy. The continuous accumulation of electromagnetic energy data will be beneficial to the study on the transmission and variation characteristics of electromagnetic energy in the polar ionosphere in China. In this paper, we estimated the distribution of field-aligned Poynting flux, horizontal convection electric field and magnetic field perturbation in the dayside polar cap based on the plasma velocity and magnetic field data of DMSP F17 satellite in the northern hemisphere during 2014-2016. The initial DMSP F17 satellite data included in this dataset are of high quality. The estimation process is rigorous and reasonable, and the data records are complete. The dataset can provide important data support for the study on energy transport and dissipation in the ionosphere/thermosphere in the polar region.

Rayleigh‐Taylor Instability Observed at the Dayside Magnetopause Under Northward Interplanetary Magnetic Field

AbstractUnder northward interplanetary magnetic field, periodical fluctuations with the period of 85 s have been observed by one of the Time History of Events and Macroscale Interactions during Substorms spacecraft at the dayside magnetopause when the solar wind dynamic pressure suddenly dropped. The observed magnetic field distortions, characterized by the compression of the main component as well as the flapping of the perpendicular components, are in line with the theoretical predictions of the Rayleigh‐Taylor (R‐T) instability excited at the magnetopause. With the convective electric field and the mean electric field removed, the perturbations in the electric field are identified as typical two sinusoidal signals with a 90° phase difference, consistent with previous prediction of the attendant electrostatic field arising from the R‐T instability. The transverse motions of the plasmas resulting from the electric drifting driven by the electrostatic field are observed both in pitch‐angle distributions and in distribution functions. The growth rate of the R‐T instability is about 43 s, implying that the instability has time to grow during the disturbances. Using the Gauss theorem, the calculated net charge density based on the electric field observation is one part of 27 compared to the totally observed plasma density, indicating that only a tiny fraction of the charge separates to set up the electrostatic field, which is due to a collective effect in the plasma.

Particle-in-cell modelling of comet 67P/Churyumov-Gerasimenko

Context.Sufficiently far from the Sun, all comets go through a phase of low activity. Rosetta observations at large heliocentric distances of approximately 3 au showed that the plasma at a low-activity comet is affected by both steady state electric fields and low-frequency waves.Aims.Our goal is to provide a model for the electric fields in the inner coma at a low-activity comet and to simulate waves and field structures farther away from the nucleus.Methods.We compare analytical models for the convective, ambipolar, and polarisation electric fields to the results of an electrostatic particle-in-cell simulation of a scaled-down low-activity comet.Results.We find good agreement between the steady state field model and the simulation results close to the nucleus. At larger cometocentric distances, waves dominate the electric field. These waves are interpreted as the scaled-down electrostatic limit of the previously observed singing comet waves. The comet ion density is not spherically symmetric.Conclusions.Low-activity comets can be modelled using electrostatic particle-in-cell simulations of a scaled-down system. Outside the innermost part of the coma (r≳ 40 km), the plasma is not spherically symmetric and the electric field is dominated by waves.

Forces, electric fields and currents at the subsolar martian MPB: MAVEN observations and multifluid MHD simulation

The Martian MPB (Magnetic Pileup Boundary) is a key boundary in the Mars/Solar Wind interaction as it is here that part of the momentum and energy from the solar wind plasma are transferred to the planetary plasma. Since this interaction is for the most part collisionless, the transfer is mediated by electric and magnetic fields. The acceleration processes and the interaction of particles with electromagnetic fields operate at spatial scales determined by the ambient particle populations. In particular, in regions with sizes of the order of the ion inertial length (ion scales), the Hall electric field is expected to be dominant.In the present work we combine data from the MAVEN spacecraft along one orbit around Mars and multifluid MHD simulation results to study the role of electric fields, currents and forces at the MPB at ion scales. In particular, we find that the current densities deduced from MAVEN data (J ∼ 238 nA/m2) of the same order as the values obtained in the simulation (J ∼ 56-156 nA/m2) and that the Hall electric force points sunward in both cases. In addition, we find that in the subsolar MPB current layer the Hall electric field (∼3.2 mV/m) dominates over the solar wind convective electric field (∼0.4 mV/m) and electron pressure gradient (∼0.8 mV/m). These values are consistent with previous results suggesting that the MPB thickness is of the order of the solar wind proton inertial length and support the idea that non ideal terms in Ohm’s law must be considered when analysing the dynamics of particles around plasma boundaries with ion scale thicknesses.

Dependence of Ionospheric Responses on Solar Wind Dynamic Pressure During Geomagnetic Storms Using Global Long‐Term GNSS‐TEC Data

AbstractTo elucidate the effect of solar wind dynamic pressure on the activities of ionospheric plasma irregularities in both high‐latitude and equatorial regions, we analyzed the long‐term global navigation satellite system (GNSS) total electron content (TEC) data from 2000 to 2018 and performed a superposed epoch analysis of the GNSS rate of the TEC index (ROTI), solar wind, interplanetary magnetic field (IMF), and geomagnetic index. We found that during the main phase of geomagnetic storms, the activities of ionospheric plasma irregularities were considerably enhanced in both high‐latitude and equatorial regions under high‐pressure conditions, and the equatorward edge of the auroral oval moved to lower latitudes. The poleward edge of the enhanced low‐latitude ROTI region (occurrence region of the plasma bubbles) in the evening sector extended to higher latitudes under high‐pressure conditions. During the recovery phase of geomagnetic storms, the plasma bubble occurrence in the dusk sector was suppressed under high‐pressure conditions. Our results suggest that the high‐latitude convection electric field and the penetration and disturbance dynamo electric fields at low latitudes become stronger during geomagnetic storms when the solar wind dynamic pressure is enhanced. This is because the conversion from solar wind energy to electromagnetic energy in the magnetosphere is enhanced by the formation of a high plasma pressure area in the high‐latitude cusp and mantle region. Therefore, not only the southward IMF but also solar wind dynamic pressure are important factors for varying global ionospheric responses during geomagnetic storms.

Solar wind interaction with Mars: electric field morphology and source terms

ABSTRACTThe correlation between space environment conditions and the properties of escaping ions is a central topic of Mars research. Although empirical correlations have been visible in the data, a physics-based interpretation, rather than statistics-based pictures, has not been established yet. As a first effort, we investigate the electric field, the direct contributor to ion acceleration, in the Mars plasma environment from a hybrid plasma model (particle ions and fluid electrons). We use Amitis, a hybrid model combined with an observation-based ionospheric model, to simulate the Mars–solar wind interaction under nominal solar wind plasma conditions for perpendicular and Parker spiral directions of the interplanetary magnetic field (IMF). The simulations show following results: (1) the electric field morphology is structured by the IMF direction and the different plasma domains in the solar wind–Mars interaction; (2) asymmetry of the electric field between the hemispheres where the convective electric field points inward and outward, respectively, due to the mass loading and asymmetric draping of the magnetic field lines; (3) the motional electric field dominates in most regions, especially in the dayside magnetosheath; and (4) the Hall term is an order of magnitude weaker and significant in the magnetotail and plasma boundaries for a perpendicular IMF case. The Hall term is relatively stronger for the Parker spiral case. (5) The ambipolar electric field, in principle, agrees with Mars Atmosphere and Volatile Evolution measurements in the magnetosheath.

A MAVEN Case Study of Radial IMF at Mars: Impacts on the Dayside Ionosphere

AbstractThe solar wind interaction with Mars controls the transfer of energy and momentum from the solar wind into the magnetosphere, ionosphere and atmosphere, driving structure, and dynamics within each. This interaction is highly dependent on the upstream Interplanetary Magnetic Field (IMF) orientation. We use in‐situ plasma measurements made by the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission to identify several prominent features that arise when the IMF is aligned approximately parallel or antiparallel to solar wind flow (conditions known as “radial IMF”). In particular, solar wind protons and alphas are observed to directly penetrate down to periapsis altitudes, while the magnetic barrier forms deep within the dayside ionosphere. The MAVEN observations are consistent with either an ionopause‐like boundary or diamagnetic cavity forming beneath the barrier, as a consequence of the dense cold ionosphere and the absence of significant crustal magnetic fields at this periapsis location. The planetary ions above the magnetic barrier are exposed to solar wind flow and subsequent mass‐loading. The (convective electric field or “ion pickup”) force is weak and highly variable during radial IMF. While wave particle interactions and subsequent wave heating contribute to incorporating the heavy planetary ions into the solar wind flow, the solar wind momentum is not fully deflected around the obstacle and is delivered into the collisional atmosphere. Significant ion heating is observed deep within the dayside ionosphere, and observed ionospheric density and temperature profiles demonstrate that these ion energization mechanisms drive significant erosion and likely escape to space.

Ionospheric Response to the Coronal Hole Activity of August 2020: A Global Multi‐Instrumental Overview

AbstractWe have studied the ionospheric response to a coronal hole event of August 2020 using the data from global ionospheric maps, ground magnetometers and parameters from the instruments onboard SWARM and thermosphere, ionosphere, mesosphere energetics and dynamics satellites. The role of different physical drivers, responsible for observed ionospheric disturbance, has been identified. On the storm day (2 August), a steady southward directed interplanetary magnetic field Bz caused the penetration of magnetospheric convection electric field and positive storm effect in daytime sectors. As a result of prompt penetration electric field (PPEF) on 2 August, a polar‐ward expansion of day‐side ionospheric plasma. On 3 August, the signatures of both disturbance dynamo electric field (DDEF) caused by disturbed thermospheric winds and PPEF have been observed. The westward PPEF and eastward disturbance DDEF on the night‐side caused a strong enhancement in ionospheric plasma parameters at the corresponding sectors. The effect of disturbed thermospheric winds and resultant electric field persisted till the end of 7 August. The large decrease in O/N2 ratio at northern mid‐latitudes which is a consequence of the seasonal impact resulted in the negative storm effects at corresponding latitudinal regions. This study has shown that although the storm of August 2020 was a minor one, the associated high speed solar wind streams emanating from a coronal hole resulted in drastic changes in ionospheric parameters including global electron content, in situ electron density and total electron content at the equatorial ionization anomaly and equatorial electric field.

Electro-magnetohydrodynamics hybrid nanofluid flow with gold and magnesium oxide nanoparticles through vertical parallel plates

The hybrid nanofluid flow under suspension of Gold and Magnesium oxide nanoparticles (Au/MgO-NPs) propagating between vertical parallel plates is investigated. Sodium alginate third-grade non-Newtonian fluid is used as the base fluid. The effect of electro-magnetohydrodynamics is also taken into account. The energy equation also includes the effect of Joule heating and viscous dissipation. Due to the nonlinear nature of the formulated differential equations, perturbation strategy is utilized to acquire the analytical solutions. Discussion and plotting are presented with respect to most significant parameters. It is analyzed that the rate of heat transfer is dramatically increased, and this is owing to an increase in the thermal conductivity of the fluid due to hybrid nanofluid. With increment in buoyancy convection parameter and electric field parameter, the flow is accelerated. It is also noted that the temperature is boosted with increasing nanoparticle volume fraction of both magnesium oxide and gold nanoparticles. A comparison with previously studied results is also included. The applications of the work include novel thermal duct processing technologies in biomedical, nuclear and process engineering.

The Dawn–Dusk Asymmetrical Distribution of Earthward Poynting Flux in the Dayside Polar Cap From DMSP

AbstractWe investigated the dawn–dusk asymmetrical distribution of quasi‐dc earthward Poynting flux (EPF) in the dayside polar cap of the Northern Hemisphere based on 3 years of observations at ∼850 km made by the Defense Meteorological Satellite Program (DMSP) F17. The satellite data have been sorted by low (Kp ≤ 2) and high (Kp > 2) geomagnetic activity, as well as the orientation and strength of interplanetary magnetic field (IMF) By and Bz components, binned by magnetic latitude, and magnetic local time. Statistical results show that the enhanced convection electric field favors the asymmetrical EPF distribution. Asymmetrical distribution characteristics are summarized as (a) there are mainly two enhanced EPF regions, near dawn and cusp and the mean EPF is 28% larger on the dawn than on the dusk for all IMF and Kp conditions. (b) The mean EPF for high Kp is 3 times greater than that for low Kp in the dayside polar cap. The enhanced EPF shifted from near the dawn for low Kp to near the cusp for high Kp. The EPF is also larger on the dawn than on the dusk for high Kp. (c) The EPF of the dayside polar cap is significantly enhanced as the IMF strength increases. Under IMF By+, EPF is greater on the dawn than on the dusk. The opposite is true under IMF By−. The IMF Bz− favors enhanced EPF and the EPF on the dawn (dusk) reaches its maximum for IMF By+ and Bz− (IMF By− and Bz−).

Statistical Study of the Ionospheric Slab Thickness at Yakutsk High-Latitude Station

The ionospheric equivalent slab thickness (EST, also named τ) is defined as the ratio of the total electron content (TEC) to the F2-layer peak electron density (NmF2), and it is a significant parameter representative of the ionosphere. This paper presents a comprehensive statistical study of the ionospheric slab thickness at Yakutsk, located at the high latitude of East Asia, using the GPS-TEC and ionosonde NmF2 data for the years 2010–2017. The results show that the τ has different diurnal and seasonal variations in high- and low-solar-activity years, and the τ is greatest in the winter, followed by the equinox, and it is smallest in the summer in both high- and low-solar-activity years, except during the noontime of low-solar-activity years. Specifically, the τ in inter of high-solar-activity year shows an approximate single peak pattern with the peak around noon, while it displays a double-peak pattern with the pre-sunrise and sunset peaks in winter of the low-solar-activity years. Moreover, the τ in the summer and equinox have smaller diurnal variations, and there are peaks with different magnitudes during the sunrise and post-sunset periods. The mainly diurnal variation of τ in different seasons of high- and low-solar-activity years can be explained within the framework of relative variation of TEC and NmF2 during the corresponding period. By defining the disturbance index (DI), which can visually assess the relationship between instantaneous values and the median, we found that the geomagnetic storm would enhance the τ at Yakutsk. An example on 7 June 2013 is also presented to analyze the physical mechanism. It should be due to the intense particle precipitation and expanded plasma convection electric field during the storm at high-latitude Yakutsk station. The results would improve the current understanding of climatological and storm-time behavior of τ at high latitudes in East Asia.

Effect of the Non‐Dipole Field on the Seasonal Variation of the Geomagnetic Sq(Y)

AbstractThe annual mean (Sq0), annual (Sq1), and semiannual (Sq2) components of the monthly averaged daily amplitude of the geomagnetic Y component during quiet period over several solar cycles at 25 mid‐low latitudes observatories were separated by means of Fourier analysis. No obvious distinction is found for the morphology of the spatial distribution of these Sq(Y) components during solar quiet and active periods, except that they are more intense in high solar activity. We found that the longitudinal variations in the Southern Hemisphere were primarily attributed to the differences in the annual component (Sq1), which is stronger at the Eurasia and Australia anomaly zones than at the South Atlantic Ocean anomaly (SAA) zones. The positive correlation between Sq0 and geomagnetic vertical component Z suggests that the convection electric fields in the dynamo region play a key role in controlling the annual mean (Sq0). On the other hand, the Sq1 exhibits a positive correlation with geomagnetic horizontal component H, implying the interhemispheric field‐aligned currents (IHFACs) may contribute to difference of the annual variation amplitude at the different observatories. Sq2 is most prominent in the SAA region while rather weak at other positive anomaly zones (in total field), which indicates there is a negative correlation between the total field anomaly and the semiannual variations.

Excitation of Two Types of Storm‐Time Pc5 ULF Waves by Ring Current Ions Based on the Magnetosphere‐Ionosphere Coupled Model

AbstractTwo types of storm‐time Pc5 waves are excited in the magnetosphere–ionosphere coupled model. We conduct magnetosphere–ionosphere (M–I) coupling between geospace environment modeling system for integrated studies‐ring current (GEMSIS‐RC) and GEMSIS‐POTential solver (GEMSIS‐POT) models in order to investigate the excitation of storm‐time Pc5 waves under more realistic conditions. The coupled model enables us to simulate ion transport from the plasma sheet by the convection electric field. First, we find the excitation of fundamental mode Pc5 waves on the dayside. These waves are generated by the drift resonance and driven by positive energy gradient of ion phase space density (PSD). The wave excitation is similar with the case without M–I coupling. Second, we detect second harmonic mode Pc5 waves with high azimuthal wave number in the dusk and premidnight region. The PSD oscillates associated with the waves, and the drift‐bounce resonance occurs at 50–80 keV ions. We find that these ions drift around the Earth and reach the nightside again at t ∼ 4,500 s, whose time scale is comparable to the drift period of these ions. At that time, inward gradient of the PSD is created, which contributes to the wave growth. This effect does not happen in the case without dawn‐to‐dusk convection electric field driven by Region 1 field aligned current (FAC). We find that the shielding by Region 2 FAC suppresses the flux of newly injected ions at the nightside, inward gradient of the PSD, and power spectra of second harmonic mode waves.

A 3D parametric Martian magnetic pileup boundary model with the effects of solar wind density, velocity, and IMF

Using global magnetohydrodynamic simulations, we construct a 3D parametric model of the Martian magnetic pileup boundary (MPB). This model employs a modified parabola function defined by four parameters. The effects of the solar wind dynamic pressure, the solar wind densities and velocities, and the intensity and orientation of the interplanetary magnetic field (IMF) are examined using 267 simulation cases. The results from our parametric model show that (1) the MPB moves closer to Mars when the upstream solar wind dynamic pressure (Pd) increases, the subsolar standoff distance decreases and the flaring degree of the Martian MPB increases with an increasing Pd according to the power-law relations. For the same Pd, a higher solar wind velocity (a lower density) leads to a farther location of the MPB from Mars, along with a larger flaring degree, which is explained by the higher solar wind convection electric fields and a stronger magnetic pileup process under these conditions. (2) Larger Y or Z components of the IMF, BY or BZ, result in a thicker pileup region and a farther MPB location from Mars, as well as a decrease in the flaring degree. The radial IMF component, BX, has little effect on the geometry of the MPB. (3) In most of the simulations used to derive the current parametric model, the strongest Martian crustal magnetic field is located on the dayside. However, for a larger value of the southward IMF, the Martian MPB is located farther away in the northern hemisphere instead of the southern hemisphere. The north-south asymmetry of the Martian MPB with the southern hemisphere being farther away is observed for other IMF directions. We suggest that the magnetic reconnection of the southward IMF with the crustal field that occurs at middle latitudes of the southern hemisphere results in different magnetic field topologies and the closer location of the MPB under these conditions. Our model results show a relatively good agreement with the previous empirical and theoretical models.

Local Time Response of Auroral Electrojet During Magnetically Disturbed Periods: DMSP and CHAMP Coordinated Observations

AbstractBased on 10 years of Defense Meteorological Satellite Program and Challenging Minisatellite Payload coordinated observations, we investigated the local time variation in the response time and strength of the auroral electrojet (AEJ) with respect to the sudden change in solar wind inputs, including merging electric field (Em), substorm, and interplanetary (IP) shock. The daytime (nighttime) AEJ responded several minutes (>30 min) after the key time of Em enhancement. For substorms and IP shocks, the AEJ at all local times showed an instantaneous response. The local time with a westward enhancement of the AEJ was wider during substorms than those during Em enhancement and IP shock. The times when the AEJ or disturbance AEJ attained peaks varied for different disturbances. At IP shock onset, the AEJ in the prenoon and postnoon increased in opposite directions to that in the quiet time. During Em enhancement and IP shock, the duskside AEJ attained a peak faster than the dawnside owing to the more rapid change in the duskside Hall conductance. The relative effects of the convection electric field and Hall conductance on the disturbance AEJ are disclosed at different local times. This study offers insights into the physical mechanisms of local time differences in the response time and strength of AEJ during disturbed periods.