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Mesospheric tide comparisons at low latitudes observed by two collocated meteor radars

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Earth and planetary Physics 2025年第1期9卷 54-68页

作者： Jian Li Wen Yi XiangHui Xue Jie Zeng HaiLun Ye JianYuan Wang JinSong Chen Na Li TingDi Chen Chinese Academy of sciences(CAS)Key Laboratory of Geospace Environment Department of Geophysics and Planetary SciencesUniversity of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Comparative Planetology Anhui Mengcheng Geophysics National Observation and Research StationUniversity of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230026China Collaborative Innovation Center of Astronautical science and Technology Harbin 150001China National Key Laboratory of Electromagnetic Environment China Research Institute of Radiowave PropagationQingdao 266107China Yunnan Kunming Electromagnetic Environment National Observation and Research Station Qujing Kunming 655000China

Accurate knowledge of mesospheric winds and waves is essential for studying the dynamics and climate in the mesosphere and lower thermosphere(MLT)*** this study,we conduct a comparative analysis of the mesosphere tidal results obtained from two adjacent meteor radars at low latitudes in Kunming,China,from November 2013 to December *** two radars operate at different frequencies of 37.5 MHz and 53.1 MHz,***,overall good agreement is observed between the two radars in terms of horizontal winds and tide *** results show that the dominant tidal waves of the zonal and meridional winds are diurnal and semidiurnal ***,we conduct an exhaustive statistical analysis to compare the tidal amplitudes and vertical wavelengths recorded by the dual radar systems,which reveals a high degree of alignment in tidal *** investigation includes variances and covariances of tidal amplitudes,which demonstrate remarkable consistency across measurements from both *** finding highlights clear uniformity in the mesospheric tidal patterns observed at low latitudes by the two neighboring meteor *** of the comparative analysis specifically underscore the significant correlation in vertical wavelength measurements,validating the robustness of radar observations for tidal research.

关键词： mesosphere and lower thermosphere region meteor radar mesospheric winds tides

Effects of mesoscale gravity waves on sporadic E simulated by a one-dimensional dynamic model

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Earth and planetary Physics 2025年第1期9卷 1-9页

作者： Xu Zhou ZeZhong Li XinAn Yue LiBo Liu Key Laboratory of Earth and planetary Physics/Heilongjiang Mohe National Geophysical Observatory/Beijing National Observatory of Space Environment Institute of Geology and GeophysicsChinese Academy of Sciences(CAS)Beijing 100029China College of Earth and planetary sciences University of Chinese Academy of SciencesBeijing 100049China CAS Center for Excellence in Comparative Planetology/CAS Key Laboratory of Geospace Environment/Mengcheng National Geophysical Observatory University of Science and Technology of ChinaHefei 230026China

In addition to being driven by tidal winds,the sporadic E(Es)layers are modulated by gravity waves(GWs),although the effects are not yet comprehensively *** this article,we discuss the effects of mesoscale GWs on the Es layers determined by using a newly developed model,MISE-1D(one-dimensional Model of Ionospheric Sporadic E),with low numerical dissipation and high *** by the wind fields resolved by the high-resolution version of the Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension(WACCM-X),the MISE-1D simulation revealed that GWs significantly influence the evolution of the Es layer above 100 km but have a very limited effect at lower *** effects of GWs are diverse and complex,generally including the generation of fluctuating wavelike structures on the Es layer with frequencies similar to those of the *** mesoscale GWs can also cause increases in the density of Es layers,or they can disperse or diffuse the Es layers and increase their *** addition,the presence of GWs is a key factor in sustaining the Es layers in some cases.

关键词： sporadic E ion tidal layer gravity waves numerical simulation

Sporadic E responds to the 2022 Tonga volcano eruptions recorded by the Meridian Project

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Earth and planetary Physics 2025年第1期9卷 20-28页

作者： YangYi Sun Tao Yu Jin Wang Chi Long School of geophysics and Geomatics China University of Geosciences(Wuhan)Wuhan 430047China School of Physics and Electronic science Guizhou Normal UniversityGuizhou 550001China

In this study,ionosonde observations over Fuke(19.5°N,109.1°E),Wuhan(30.5°N,114.4°E),and Mohe(53.5°N,122.3°E)were analyzed to demonstrate the responses of the sporadic E()to the severe atmospheric disturbances caused by the Tonga volcanic eruptions on January 15,*** most prominent signature was the disappearance of the layer after~10:00 UT over Wuhan and Fuke,which was attributed to the vertical drift caused by the *** occurred intermittently after 13:00 UT following the arrival of the tropospheric Lamb *** examine the causal mechanism for the intermittence,we also included data of horizontal winds in the mesosphere and lower thermosphere region recorded by the meteor radars at Wuhan and Mohe in this *** wind disturbances with periods of~20 hours contributed to the formation of the layer in the nighttime on January 15.

关键词： sporadic E Tonga eruptions neutral wind disturbances

An investigation on the wind profiles and gravity wave dynamics in MLT region based on the meteor radars from the Meridian Project

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Earth and planetary Physics 2025年第1期9卷 29-38页

作者： Tai Liu Zhe Wang MengXi Shi Willie Soon ShiCan Qiu department of geophysics College of the Geology Engineering and GeomaticsChang’an UniversityXi’an 710054China Center for Environmental Research and Earth sciences(CERES) SalemMA 01970USA Institute of Earth Physics and Space science(ELKH EPSS) 9400SopronHungary

The meteor radar can detect the zenith angle,azimuth,radial velocity,and altitude of meteor trails so that one can invert the wind profiles in the mesosphere and low thermosphere(MLT)region,based on the Interferometric and Doppler *** this paper,the horizontal wind field,gravity wave(GW)disturbance variance,and GW fluxes are analyzed through the meteor radar observation from 2012−2022,at Mohe(53.5°N,122.4°E)and Zuoling(30.5°N,114.6°E)stations of the(Chinese)Meridian *** Lomb−Scargle periodogram method has been utilized to analyze the periodic variations for time series with observational data *** results show that the zonal winds at both stations are eastward dominated,while the meridional winds are southward *** variance of GW disturbances in the zonal and meridional directions increases gradually with height,and there is a strong pattern of annual *** zonal momentum flux of GW changes little with height,showing weak annual *** meridional GW flux varies gradually from northward to southward with height,and the annual periodicity is *** both stations,the maximum values of zonal and meridional wind occur close to the peak heights of GW flux,with opposite *** observational evidence is consistent with the filtering *** horizontal wind velocity,GW flux,and disturbance variance of the GW at Mohe are overall smaller than those at Zuoling,indicating weaker activities in the MLT at *** power spectral density(PSD)calculated by the Lomb−Scargle periodogram shows that there are 12-month period and 6-month period in horizontal wind field,GW disturbance variance and GW flux at both stations,and especially there is also a 4-month cycle in the disturbance *** PSD of the 12-month and 6-month cycles exhibits maximum values below 88 km and above 94 km.

关键词： meteor radar wind field gravity wave Lomb−Scargle method

Electromagnetic Particle-in-Cell Simulations of Electron Holes Formed During the Electron Two-Stream Instability

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Plasma science and Technology 2013年第1期15卷 17-24页

作者：吴明雨陆全明朱洁王沛然王水 CAS Key Lab of Geospace Environment Department of Geophysics and Planetary ScienceUniversity of Science and Technology of China

Previous electrostatic particle-in-cell （PIC） simulations have pointed out that elec- tron phase-space holes （electron holes） can be formed during the nonlinear evolution of the electron two-stream instability. The parallel cuts of the parallel and perpendicular electric field have bipolar and unipolar structures in these electron holes, respectively. In this study, two-dimensional （2D） electromagnetic PIC simulations are performed in the x - y plane to investigate the evolution of the electron two-stream instability, with the emphasis on the magnetic structures associated with these electron holes in different plasma conditions. In the simulations, the background magnetic field （Bo = Boer） is along the x direction. In weakly magnetized plasma （Ωe 〈ωpe, where Ωe and ωpe are the electron gyrofrequency and electron plasma frequency, respectively）, several 2D electron holes are formed. In these 2D electron holes, the parallel cut of the fluctuating magnetic field δBx and δBz has unipolar structures, while the fluctuating magnetic field δBy has bipolar structures. In strongly magnetized plasma （Ωe 〉 ωpe）, several quasi-lD electron holes are formed. The electrostatic whistler waves with streaked structures of Ey are excited. The fluctuating mag- netic field δBx and δBz also have streaked structures. The fluctuating magnetic field δBx and δBy are produced by the current in the z direction due to the electric field drift of the trapped elec- trons, while the fluctuating magnetic field δBz can be explained by the Lorentz transformation of a moving quasielectrostatic structure. The influences of the initial temperature anisotropy on the magnetic structures of the electron holes are also analyzed. The electromagnetic whistler waves are found to be excited in weakly magnetized plasma. However, they do not have any significant effects on the electrostatic structures of the electron holes.

关键词： electron two-stream instability particle-in-cell simulation

On the Gradient of the Electron Pressure in Anti-Parallel Magnetic Reconnection

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Chinese Physics Letters 2015年第4期32卷 65-68页

作者：王焕宇黄灿陆全明王水 CAS Key Laboratory of Geospace Environment Department of Geophysics and Planetary ScienceUniversity of Science and Technology of China

We first perform a two-dimensional particle-in-cell simulation of anti-parallel magnetic reconnection to verify that in the electron diffusion region the reconnection electric field is mainly balanced by the gradient of the electron pressure. Then, by following typical electron trajectories in the fixed electromagnetic field of anti- parallel reconnection, we calculate the gradient of the electron pressure. We find that the resulted gradient of the electron pressure is equal to the reconnection electric field. This indicates that in the electron diffusion region the reconnection electric field is balanced by the gradient of the electron pressure, which results from the electron nongyrotropic motions. Our result gives a microphysical explanation of the balance between the reconnection electric field and the gradient of the electron pressure.

关键词： On the Gradient of the Electron Pressure in Anti-Parallel Magnetic Reconnection

The Efficiency of Ion Stochastic Heating by a Monochromatic Obliquely Propagating Low-Frequency Alfven Wave

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Plasma science and Technology 2014年第10期16卷 919-923页

作者：孙继承高新亮陆全明王水 CAS Key Lab of Geospace Environment Department of Geophysics and Planetary ScienceUniversity of Science and Technology of China

Abstract The process of ion heating by a monochromatic obliquely propagating low-frequency Alfven wave is investigated. This process can be roughly divided into three stages： at first, the ions are picked up by the Alfven wave in several gyro-periods and a bulk velocity in the transverse direction is achieved; then, the ions are scattered in the transverse direction by the wave, which produces phase differences between the ions and leads to ion heating, especially in the perpendicular direction; and finally, the ions are stochastically heated due to the sub- cyclotron resonance. In this paper, with a test particle method, the efficiency and time scale of the ion stochastic heating by a monochromatic obliquely propagating low-frequency Alfven wave are studied. The results show that with the increase of the amplitude, frequency, and propagation angle of the AlDen wave, the efficiency of the ion stochastic heating increases, while the time scale of the ion stochastic heating decreases. With the increase of the plasma beta β, the ions are stochastically heated with less efficiency, and the time scale increases. We also investigate the heating of heavy ion species （He2＋ and O5＋）, which can be heated with a higher efficiency by the oblique Alfven wave.

关键词： Alfven wave stochastic heating test particle method

Disintegration of an eruptive filament via interactions with quasi-separatrix layers

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science China(Physics,Mechanics & Astronomy) 2018年第6期61卷 84-90页

作者： Rui Liu Jun Chen YuMing Wang CAS Key Laboratory of Geospace Environment Department of Geophysics and Planetary SciencesUniversity of Science and Technology of China

The disintegration of solar filaments via mass drainage is a frequently observed phenomenon during a variety of filament *** is generally considered that the draining of dense filament material is directed by both gravity and magnetic field, yet the detailed process remains elusive. Here we report on a partial filament eruption during which filament material drains downward to the surface not only along the filament's legs, but to a remote flare ribbon through a fan-out curtain-like structure. It is found that the magnetic configuration is characterized by two conjoining dome-like quasi-sepratrix layers(QSLs). The filament is located underneath one QSL dome, whose footprint apparently bounds the major flare ribbons resulting from the filament eruption,whereas the remote flare ribbon matches well with the other QSL dome's far-side footprint. We suggest that the interaction of the filament with the overlying QSLs results in the splitting and disintegration of the filament.

关键词： magnetic reconnection filament eruptions flares coronal mass ejection

Numerical Simulations of Magnetic Reconnection in an Asymmetric Current Sheet

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Chinese Physics Letters 2013年第12期30卷 79-82页

作者： WANG Pei-Ran HUANG Can LU Quan-Ming WANG Rong-Sheng WANG Shui CAS Key Laboratory of Geospace Environment Department of Geophysics and Planetary ScienceUniversity of Science and Technology of ChinaHefei 230026 Institute of Geology and geophysics Chinese Academy of SciencesBeijing 100029

Previous particle-in-cell simulations have shown that electron phase-space holes(electron holes),where the associated parallel electric field has a bipolar structure,exist near the four separatrices in anti-parallel magnetic *** performing two-dimensional(2-D)particle-in-cell(PIC)simulations,here we investigate magnetic reconnection in an asymmetric current sheet,with emphasis on the parallel electric field near the *** with magnetic reconnection in a symmetric current sheet,it is found that the parallel electric field with a bipolar structure only exists around the separatrices in the upper region with a lower density(upper separatrices).Such a bipolar structure of the parallel electric field is considered to be associated with electron holes resulting from the nonlinear evolution of the electron beam instability excited by the high-speed electron flow formed after their acceleration around the X *** disappearance of the parallel electric field around the separatrices in the lower region with a higher density(lower separatrices)may be due to the transverse instability,which is unstable in a weak magnetized plasma.

关键词： reconnection structure field