Journal of Geophysical Research: Space Physics最新文献

筛选
英文 中文
Auroral and Magnetotail Dynamics During Quiet-Time STEVE and SAID 静默时段的极光和磁尾动力学 STEVE 和 SAID
IF 2.6 2区 地球科学
Journal of Geophysical Research: Space Physics Pub Date : 2024-11-05 DOI: 10.1029/2024JA032941
Y. Nishimura, B. Gallardo-Lacourt, E. F. Donovan, V. Angelopoulos, N. Nishitani
{"title":"Auroral and Magnetotail Dynamics During Quiet-Time STEVE and SAID","authors":"Y. Nishimura,&nbsp;B. Gallardo-Lacourt,&nbsp;E. F. Donovan,&nbsp;V. Angelopoulos,&nbsp;N. Nishitani","doi":"10.1029/2024JA032941","DOIUrl":"https://doi.org/10.1029/2024JA032941","url":null,"abstract":"<p>Although Strong Thermal Emission Velocity Enhancement (STEVE) and subauroral ion drifts (SAID) are often considered in the context of geomagnetically disturbed times, we found that STEVE and SAID can occur even during quiet times. Quiet-time STEVE has the same properties as substorm-time STEVE, including its purple/mauve color and occurrence near the equatorward boundary of the pre-midnight auroral oval. Quiet-time STEVE and SAID emerged during a non-substorm auroral intensification at or near the poleward boundary of the auroral oval followed by a streamer. Quiet-time STEVE only lasted a few minutes but can reappear multiple times, and its latitude was much higher than substorm-time STEVE due to the contracted auroral oval. The THEMIS satellites in the plasma sheet detected dipolarization fronts and fast flows associated with the auroral intensification, indicating that the transient energy release in the magnetotail was the source of quiet-time STEVE and SAID. Particle injection was weaker and electron temperature was lower than the events without quiet-time STEVE. The plasmapause extended beyond the geosynchronous orbit, and the ring current and tail current were weak. The interplanetary magnetic field (IMF) <i>B</i><sub>z</sub> was close to zero, while the IMF <i>B</i><sub>x</sub> was dominant. We suggest that the small energy release in the quiet magnetosphere can significantly impact the flow and field-aligned current system.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"129 11","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Martian Ionosphere-Thermosphere Coupling in Longitude Structures: Statistical Results for the Main Ionization Peak Height 经度结构中的火星电离层-热层耦合:主电离峰高的统计结果
IF 2.6 2区 地球科学
Journal of Geophysical Research: Space Physics Pub Date : 2024-11-02 DOI: 10.1029/2024JA032839
Yiding Chen, Libo Liu, Huijun Le, Ruilong Zhang
{"title":"Martian Ionosphere-Thermosphere Coupling in Longitude Structures: Statistical Results for the Main Ionization Peak Height","authors":"Yiding Chen,&nbsp;Libo Liu,&nbsp;Huijun Le,&nbsp;Ruilong Zhang","doi":"10.1029/2024JA032839","DOIUrl":"https://doi.org/10.1029/2024JA032839","url":null,"abstract":"<p>The Martian ionosphere-thermosphere (I-T) coupling is variable due to complex variations of the driving factors such as atmospheric tides and crustal magnetic fields. In this study, variability of the I-T coupling in longitude structures was investigated using a series of data segments of the MGS ionospheric measurements. Measurements in each data segment can cover different longitudes, and the solar forcing and local solar time just change a little. Ionospheric and thermospheric longitude variations are statistically correlated. Ionospheric peak electron density (<i>N</i><sub><i>m</i></sub><i>M</i><sub>2</sub>) decreases while ionospheric main peak height (<i>h</i><sub><i>m</i></sub><i>M</i><sub>2</sub>) increases with increasing neutral scale height (<i>H</i><sub><i>n</i></sub>) along longitudes. These correlated longitude variations are consistent with the photochemical coupling that <i>H</i><sub><i>n</i></sub> longitude disturbances induce ionospheric longitude structure through photochemical processes. Statistically, <i>N</i><sub><i>m</i></sub><i>M</i><sub>2</sub> is a better indicator than <i>h</i><sub><i>m</i></sub><i>M</i><sub>2</sub> for the <i>H</i><sub><i>n</i></sub> disturbances in the lower thermosphere. <i>H</i><sub><i>n</i></sub> longitude variation intensity is a crucial factor affecting the photochemical I-T coupling in longitude structures; it is closely related to <i>N</i><sub><i>m</i></sub><i>M</i><sub>2</sub> longitude variation intensity and tends to decline with increasing altitudes. The I-T coupling in longitude structures tends to decline near the terminator, which is in line with the declining longitude variation of <i>H</i><sub><i>n</i></sub> with increasing altitudes since <i>h</i><sub><i>m</i></sub><i>M</i><sub>2</sub> significantly increases near the terminator. Moreover, it tends to enhance at high solar activity level due to increased photoionization rate. The I-T coupling in longitude structures also shows seasonal dependence, as seasonal variation of <i>h</i><sub><i>m</i></sub><i>M</i><sub>2</sub> can affect the <i>H</i><sub><i>n</i></sub> longitude variation intensity nearby the ionospheric main peak.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"129 11","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Earthward-Tailward Asymmetry of Plasma Temperature in Reconnection Outflow in Earth's Magnetotail 地球磁尾再连接外流中等离子体温度的地尾不对称现象
IF 2.6 2区 地球科学
Journal of Geophysical Research: Space Physics Pub Date : 2024-11-02 DOI: 10.1029/2024JA032835
Fekireselassie Beyene, Vassilis Angelopoulos, Andrei Runov, Anton Artemyev
{"title":"Earthward-Tailward Asymmetry of Plasma Temperature in Reconnection Outflow in Earth's Magnetotail","authors":"Fekireselassie Beyene,&nbsp;Vassilis Angelopoulos,&nbsp;Andrei Runov,&nbsp;Anton Artemyev","doi":"10.1029/2024JA032835","DOIUrl":"https://doi.org/10.1029/2024JA032835","url":null,"abstract":"<p>To explore the asymmetry in ion and electron heating at Earth's magnetotail at mid-tail distances (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>X</mi>\u0000 <mi>GSM</mi>\u0000 </msub>\u0000 <mo>&lt;</mo>\u0000 </mrow>\u0000 <annotation> ${X}_{mathit{GSM}}&lt; $</annotation>\u0000 </semantics></math> −30 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>R</mi>\u0000 <mi>E</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${R}_{E}$</annotation>\u0000 </semantics></math>), we analyze near-simultaneous observations of reconnection outflows from two opposite sides of reconnection sites at those distances using Magnetospheric Multiscale (MMS) and Acceleration, Reconnection, Turbulence and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) data. We report a pronounced temperature asymmetry between the earthward and tailward reconnection outflows. The asymmetry is more significant for electrons than for ions: Earthward moving ions are only three times hotter than tailward ones, but earthward moving electrons are 5–20 times hotter than tailward ones. The closed field-line topology on the earthward side of the reconnection region, as opposed to the open topology on the tailward side, is likely a critical contributor to this asymmetry. These findings cast light on the underlying mechanisms of particle heating and energization in magnetotail reconnection, highlighting the significant role of Earth's dipolar magnetic field. This study offers insights for refining magnetic reconnection models, emphasizing the importance of incorporating realistic magnetic field topologies to accurately simulate the heating and energization processes observed in space plasma environments.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"129 11","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Nightside Electron Precipitation Patterns as Observed by ELFIN and CIRBE CubeSats ELFIN 和 CIRBE 立方体卫星观测到的夜侧电子沉降模式
IF 2.6 2区 地球科学
Journal of Geophysical Research: Space Physics Pub Date : 2024-11-02 DOI: 10.1029/2024JA033051
Kun Zhang, Anton V. Artemyev, Xinlin Li, Xiao-Jia Zhang, Vassilis Angelopoulos, Yang Mei, Zheng Xiang, Niklas Grimmich
{"title":"Nightside Electron Precipitation Patterns as Observed by ELFIN and CIRBE CubeSats","authors":"Kun Zhang,&nbsp;Anton V. Artemyev,&nbsp;Xinlin Li,&nbsp;Xiao-Jia Zhang,&nbsp;Vassilis Angelopoulos,&nbsp;Yang Mei,&nbsp;Zheng Xiang,&nbsp;Niklas Grimmich","doi":"10.1029/2024JA033051","DOIUrl":"https://doi.org/10.1029/2024JA033051","url":null,"abstract":"<p>The rapidly expanding fleet of low-altitude CubeSats equipped with energetic particle detectors brings new opportunities for monitoring the dynamics of the radiation belt and near-Earth plasma sheet. Despite their small sizes, CubeSats can carry state-of-the-art instruments that provide electron flux measurements with finer energy resolution and broader energy coverage, compared to conventional missions such as POES satellites. The recently launched CIRBE CubeSat measures 250–6,000 keV electrons with extremely high energy resolution, however, CIRBE typically only measures locally-trapped electrons and cannot directly measure the precipitating electrons. This work aims to develop a technique for identifying indications of nightside precipitation using the locally-trapped electron measurements by the CIRBE CubeSat. This study focuses on two main types of drivers for nightside precipitation: electron scattering by the curvature of magnetic field lines in the magnetotail current sheet and electron scattering by resonance with electromagnetic ion cyclotron (EMIC) waves. Using energy and pitch-angle resolved electron fluxes from the low-altitude ELFIN CubeSat, we reveal the features that distinguish between these two precipitation mechanisms based solely on locally-trapped flux measurements. Then we present measurements from four CIRBE orbits and demonstrate the applicability of the proposed technique to the investigation of nightside precipitation using CIRBE observations, enabling separation between precipitation induced by curvature scattering and EMIC waves in nearby regions. Our study underscores the feasibility of employing high-energy-resolution CIRBE measurements for detecting nightside precipitation of relativistic electrons. Additionally, we briefly discuss outstanding scientific questions about these precipitation patterns that could be addressed with CIRBE measurements.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"129 11","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Test Particle Simulations of the Butterfly Distribution of Relativistic Electrons in Magnetic Dips 磁倾中相对论电子蝶形分布的测试粒子模拟
IF 2.6 2区 地球科学
Journal of Geophysical Research: Space Physics Pub Date : 2024-11-01 DOI: 10.1029/2024JA032546
Yingying Zhao, Hui Zhu
{"title":"Test Particle Simulations of the Butterfly Distribution of Relativistic Electrons in Magnetic Dips","authors":"Yingying Zhao,&nbsp;Hui Zhu","doi":"10.1029/2024JA032546","DOIUrl":"https://doi.org/10.1029/2024JA032546","url":null,"abstract":"<p>Magnetic dips are the localized depression of magnetic field in the inner magnetosphere and are suggested to play an important role in the formation of the butterfly distribution of relativistic electrons in the radiation belts. In this study, we conduct test-particle simulations to trace the electrons' trajectory within a magnetic dip and evaluate the response of PAD based on the long-term averaged flux of electrons between <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>L</mi>\u0000 </mrow>\u0000 <annotation> $L$</annotation>\u0000 </semantics></math> = 3–6 from Van Allen Probes. Our results show that the electron dynamics are significantly changed by magnetic dips, especially at the dip center. In a magnetic dip, the electrons' energy, <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>L</mi>\u0000 </mrow>\u0000 <annotation> $L$</annotation>\u0000 </semantics></math>-shell, and pitch angle decrease, and the variation in <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>L</mi>\u0000 </mrow>\u0000 <annotation> $L$</annotation>\u0000 </semantics></math>-shell is more significant than the pitch angle and energy. Based on the observational electron fluxes, the electron butterfly-like distributions are well reproduced by the simulation. Moreover, the parameterizations reveal that the butterfly distribution of electrons is closely related to the electron's energy, location, and depth of the magnetic dip. A negative radial gradient of electron flux also plays a potentially crucial role in the formation of the electron butterfly distribution. Our study provides deep insights into the evolution of the butterfly distribution of relativistic electrons within magnetic dips.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"129 11","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Electron Scattering Due To Asymmetric Drift-Orbit Bifurcation: Geometric Jumps of Adiabatic Invariant 不对称漂移轨道分岔引起的电子散射:绝热不变量的几何跃迁
IF 2.6 2区 地球科学
Journal of Geophysical Research: Space Physics Pub Date : 2024-11-01 DOI: 10.1029/2024JA032987
S. R. Kamaletdinov, A. V. Artemyev, V. Angelopoulos, A. I. Neishtadt
{"title":"Electron Scattering Due To Asymmetric Drift-Orbit Bifurcation: Geometric Jumps of Adiabatic Invariant","authors":"S. R. Kamaletdinov,&nbsp;A. V. Artemyev,&nbsp;V. Angelopoulos,&nbsp;A. I. Neishtadt","doi":"10.1029/2024JA032987","DOIUrl":"https://doi.org/10.1029/2024JA032987","url":null,"abstract":"&lt;p&gt;Radial transport of energetic electrons is one of the key processes responsible for the variability of the outer radiation belt. This transport amounts to a violation of the drift motion. One of the mechanisms that can lead to such violation and associated radial transport is drift-orbit bifurcation. This arises naturally from solar wind compression of the dayside magnetosphere, which results in a local maximum of the field strength at the equator and two off-equatorial minima at the north and south segments of the field line. Azimuthally drifting, near-equatorially mirroring electrons can be trapped, bouncing along the field line in either of those minima for a portion of their drift orbit around Earth. Trapping and the ensuing de-trapping are associated with jumps of the second adiabatic invariant, making the third adiabatic invariant undefined and the drift orbit open. Drift-orbit bifurcation has been previously investigated for north-south and dawn-dusk symmetric configurations of the magnetospheric magnetic field. Here we study the implications of an asymmetry in the drift-orbit bifurcation due to a large IMF &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;B&lt;/mi&gt;\u0000 &lt;mi&gt;y&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${B}_{y}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; field. Using the theory of separatrix crossings in Hamiltonian systems with a slow and a fast variable, we demonstrate that there are geometric (in phase space) jumps of adiabatic invariants due to the asymmetry of the magnetic field configuration. These jumps have magnitudes comparable to the initial invariant magnitudes and are dictated by the topology of the magnetic field. We develop a technique that allows estimation of the jumps in a given magnetic field configuration. We also assess the radial transport expected from asymmetric drift-orbit bifurcation. We find that such transport can reach &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $pm 1$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mi&gt;E&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{R}}_{E}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; (Earth's radius) per drift period, depending on the magnitude of the IMF &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;B&lt;/mi&gt;\u0000 &lt;mi&gt;y&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 ","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"129 11","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
On the Inverse Correlation Between the Thermosphere Winter Helium Bulge and Solar Activity: Impact of Gravity Wave Drag From the Mesosphere 论热层冬季氦凸起与太阳活动之间的反相关性:中间层重力波拖曳的影响
IF 2.6 2区 地球科学
Journal of Geophysical Research: Space Physics Pub Date : 2024-10-29 DOI: 10.1029/2024JA033189
Dexin Ren, Jiuhou Lei, Han-Li Liu, Wenbin Wang, Jia Yue, Huixin Liu, Yu Liu
{"title":"On the Inverse Correlation Between the Thermosphere Winter Helium Bulge and Solar Activity: Impact of Gravity Wave Drag From the Mesosphere","authors":"Dexin Ren,&nbsp;Jiuhou Lei,&nbsp;Han-Li Liu,&nbsp;Wenbin Wang,&nbsp;Jia Yue,&nbsp;Huixin Liu,&nbsp;Yu Liu","doi":"10.1029/2024JA033189","DOIUrl":"https://doi.org/10.1029/2024JA033189","url":null,"abstract":"<p>Understanding the temporal and spatial variations in the ideal inert tracer helium can provide insight into the dynamic evolution of the thermosphere. The magnitude of the thermospheric winter helium bulge was inversely correlated with the level of solar activity. However, this feature has been found to be not reproduced by the Thermosphere-Ionosphere Electrodynamic General Circulation Model (TIEGCM), and the associated physical mechanisms remain unknown. Using the Thermosphere-Ionosphere-Mesosphere Electrodynamic General Circulation Model (TIME-GCM), we found that mesospheric gravity wave drag (GWD) is a factor contributing to this inverse correlation. Specifically, the summer-to-winter circulation in thermosphere becomes the main cause of the helium bulge, as mesospheric GWD can play a role in strengthening this circulation. The GWD contributions to temperature change below the lower thermosphere do not depend prominently on solar activity. However, because the temperature impacts on the pressure gradient force are height-integrated according to the background temperature of the neutral gas, the higher background temperature in the thermosphere at the solar maximum corresponds to a relatively weaker response in pressure gradient force in the thermosphere. Therefore, the response of the thermospheric circulation that might be expected to accompany increasing solar activity is suppressed due to the influence of mesospheric GWD, which results in a decrease in the magnitude of the winter helium bulge with increasing solar activity. Thus, our results demonstrated that lower atmosphere forcing can play a significant role in the response of thermospheric helium to solar activity.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"129 11","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Modeling the Post-Midnight Equatorial Plasma Bubbles With SAMI3/SD-WACCM-X: Large-Scale Wave Structure 利用 SAMI3/SD-WACCM-X 模拟后半夜赤道等离子气泡:大尺度波浪结构
IF 2.6 2区 地球科学
Journal of Geophysical Research: Space Physics Pub Date : 2024-10-29 DOI: 10.1029/2024JA033023
Min-Yang Chou, Jia Yue, Sarah McDonald, Fabrizio Sassi, Jennifer Tate, Nicholas Pedatella, V. Lynn Harvey
{"title":"Modeling the Post-Midnight Equatorial Plasma Bubbles With SAMI3/SD-WACCM-X: Large-Scale Wave Structure","authors":"Min-Yang Chou,&nbsp;Jia Yue,&nbsp;Sarah McDonald,&nbsp;Fabrizio Sassi,&nbsp;Jennifer Tate,&nbsp;Nicholas Pedatella,&nbsp;V. Lynn Harvey","doi":"10.1029/2024JA033023","DOIUrl":"https://doi.org/10.1029/2024JA033023","url":null,"abstract":"<p>This study investigates the relative significance of gravity wave and gravity dynamo effects in large-scale wave structure (LSWS) development using the coupled Sami3 is Also a Model of the Ionosphere (SAMI3) and Specified Dynamics Whole Atmosphere Community Climate Model with thermosphere-ionosphere eXtension (SD-WACCM-X). Simulations show significant vertical E × B drift perturbations associated with gravity waves in the F region after ∼1700 LT, leading to LSWS near midnight. Notably, LSWS can occur independently of gravity-driven dynamo current, emphasizing the significance of the gravity wave wind dynamo mechanism. However, LSWS exhibits more pronounced vertical E × B drift perturbations, indicating the involvement of background wind fields. Both gravity wave and background wind dynamo effects cause LSWS to grow vertically by ∼20 km and extend to ±10° in latitude. Gravity-driven Pedersen current, therefore, plays a role in amplifying the upwelling growth and equatorial plasma bubble development. Furthermore, simulations demonstrate the emergence of predawn ionospheric irregularities in the bottomside F layer, even without gravity-driven currents, attributed to concentric gravity waves over the magnetic equator. A comparison between FORMOSAT-7/COSMIC2 and SAMI3 ion density is also conducted. These findings emphasize the significant influence of gravity waves and background wind fields on the formation of LSWS and irregularities.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"129 11","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JA033023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Magnetosheath Plasma Flow and Its Response to IMF and Geodipole Tilt as Obtained From the Data-Based Modeling 基于数据模型的磁鞘等离子体流及其对 IMF 和地球极倾斜的响应
IF 2.6 2区 地球科学
Journal of Geophysical Research: Space Physics Pub Date : 2024-10-29 DOI: 10.1029/2024JA033233
N. A. Tsyganenko, V. S. Semenov, N. V. Erkaev, N. T. Gubaidulin
{"title":"Magnetosheath Plasma Flow and Its Response to IMF and Geodipole Tilt as Obtained From the Data-Based Modeling","authors":"N. A. Tsyganenko,&nbsp;V. S. Semenov,&nbsp;N. V. Erkaev,&nbsp;N. T. Gubaidulin","doi":"10.1029/2024JA033233","DOIUrl":"https://doi.org/10.1029/2024JA033233","url":null,"abstract":"<p>Large-scale patterns of the steady-state magnetosheath plasma flow and their dependence on the interplanetary magnetic field (IMF) have been reconstructed for the first time on the basis of large multi-year multi-mission pool of spacecraft observations, concurrent interplanetary data, and an empirical high-resolution model. The flow model architecture builds upon a recently developed magnetosheath magnetic field representation by flexible expansions of its toroidal and poloidal components in a coordinate system, naturally conformed with the magnetopause and bow shock shapes. The model includes two physics-based flow symmetry modes: the first one treats the magnetosphere as an axisymmetric unmagnetized obstacle, whereas the second mode takes into account the geodipole tilt, an important factor in the reconnection effects. The spacecraft data pool includes 1-min average data by Themis (2007–2024), Cluster (2001–2022), and MMS-1 (2015–2024) missions, as well as OMNI interplanetary data. The model drivers include the solar wind particle flux, IMF components, and the geodipole tilt angle. The model calculations faithfully reproduce the average plasma flow geometry and substantial effects have been found of the IMF orientation and magnitude, a principal factor that defines electromagnetic forces inside the magnetosheath. A strong dependence of the magnetosheath flow patterns on the Earth's dipole tilt indicates an important contribution of reconnection effects at the magnetopause to the solar wind particle transport around the dayside magnetosphere.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"129 11","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Sporadic E Layer Intensification in the Winter of 2009 Examined by FORMOSAT-3/COSMIC RO Data and GAIA Model 用 FORMOSAT-3/COSMIC RO 数据和 GAIA 模式研究 2009 年冬季的零星 E 层增厚现象
IF 2.6 2区 地球科学
Journal of Geophysical Research: Space Physics Pub Date : 2024-10-29 DOI: 10.1029/2024JA033026
Satoshi Andoh, Akinori Saito, Hiroyuki Shinagawa
{"title":"Sporadic E Layer Intensification in the Winter of 2009 Examined by FORMOSAT-3/COSMIC RO Data and GAIA Model","authors":"Satoshi Andoh,&nbsp;Akinori Saito,&nbsp;Hiroyuki Shinagawa","doi":"10.1029/2024JA033026","DOIUrl":"https://doi.org/10.1029/2024JA033026","url":null,"abstract":"<p>This study examines the role of winds in wintertime sporadic E layer intensification (WEsLI) in 2009 from a global viewpoint. Previous studies showed that sporadic E layer (EsL) intensity had increased for 20–30 days in some winters, although intense EsLs do not form generally in winter. A recent study found that vertical ion convergence (VIC) driven by intensified migrating semidiurnal (SW2) tides caused WEsLI at middle latitudes in 2009. However, no studies have investigated the global distributions and generation mechanisms of WEsLI in 2009. Herein, we employed FORMOSAT-3/COSMIC radio occultations to investigate the global distributions of WEsLI in 2009. Distributions of VIC driven by winds obtained from the Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy were compared with global WEsLI distributions to elucidate the role of winds in WEsLI. We found that WEsLI in 2009 occurred at geomagnetic low/middle latitudes except between <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>60</mn>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> $60{}^{circ}$</annotation>\u0000 </semantics></math>W and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>80</mn>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> $80{}^{circ}$</annotation>\u0000 </semantics></math>E. WEsLI was observed below 120 km altitudes, especially at 12–17 local times. WEsLI was attributable to VIC driven by SW2 tides, migrating diurnal tides, and eastward propagating diurnal tides with wavenumber 3. Tidal amplifications were possibly related to mesospheric/stratospheric atmospheric variations such as sudden stratospheric warming, zonal mean zonal winds, and quasi-biennial oscillations. WEsLI in 2009 is further evidence of the coupling between EsLs and mesospheric/stratospheric atmospheric variations through tidal modifications.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"129 11","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信