Journal of Geophysical Research: Space Physics最新文献

{"title":"Morphology of Twisted Flux Ropes and Plasma Motions in a Prominence-Cavity System Observed From Two Opposite Viewpoints","authors":"P. T. Jain Jacob,&nbsp;Ram Ajor Maurya","doi":"10.1029/2024JA033479","DOIUrl":"https://doi.org/10.1029/2024JA033479","url":null,"abstract":"<p>We investigate the three-dimensional structures of a prominence-cavity system from two distinct vantage points. For this purpose, we have used the observations recorded by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory and the Extreme Ultraviolet Imager (EUVI) on board the Solar Terrestrial Relations Observatory - Ahead (STEREO-A). Our analysis reveals that the prominence-cavity system was formed by the emergence of two oppositely rotating magnetic structures from the photosphere. The cavity, identified as an intensity-depleted region located above the prominence, was surrounded by horn-like structures. These prominence-horns, observed by both observatories, unveiled the presence of twisted flux ropes within the cavity. As the system evolved, we observed the prominence horns undergoing repeated upward motion accompanied by multiple instances of downward plasma motions. These observations suggest the occurrence of magnetic reconnection processes within the prominence-cavity system. We tracked the dynamics of these plasma motions in details, estimating their average speeds, physical parameters including the temperature, magnetic field, and the plasma density. In its final stage, the structure exhibited positive helicity, with left-bearing barbs that reflected the twisted flux rope morphology of the prominence. Our findings indicate that the prominence-cavity system was non-eruptive due to the presence of oppositely directed twist and writhe, which helped to conserve it's helicity.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612364","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}

{"title":"Properties of EMIC Waves and EMIC Wave-Driven Electron Precipitation in Subauroral Latitudes Observed at Athabasca, Canada","authors":"Asuka Hirai,&nbsp;Fuminori Tsuchiya,&nbsp;Takahiro Obara,&nbsp;Yoshizumi Miyoshi,&nbsp;Yuto Katoh,&nbsp;Yasumasa Kasaba,&nbsp;Kazuo Shiokawa,&nbsp;Atsushi Kumamoto,&nbsp;Yoshiya Kasahara,&nbsp;Shoya Matsuda,&nbsp;Hiroaki Misawa,&nbsp;Satoshi Kurita,&nbsp;Chae-Woo Jun,&nbsp;Hiroyo Ohya,&nbsp;Martin G. Connors","doi":"10.1029/2024JA033357","DOIUrl":"https://doi.org/10.1029/2024JA033357","url":null,"abstract":"<p>Electromagnetic ion cyclotron (EMIC) waves are believed to cause the loss of relativistic electrons from the outer radiation belt into the atmosphere due to pitch angle scattering. However, it is still unclear whether all EMIC waves can scatter relativistic electrons or which conditions are favorable for pitch angle scattering by EMIC waves. In this study, we performed a 2-year data analysis of EMIC waves and EMIC wave-driven electron precipitation (EP), from 1 November 2016–31 October 2018. Electromagnetic ion cyclotron waves were observed using a ground-based magnetometer installed at Athabasca (ATH, <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>L</mi>\u0000 <mo>=</mo>\u0000 </mrow>\u0000 <annotation> $L=$</annotation>\u0000 </semantics></math>4.3), Canada. Electron precipitation events were identified from very low-frequency radio waves propagated from the transmitters at North Dakota (NDK, <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>L</mi>\u0000 <mo>=</mo>\u0000 </mrow>\u0000 <annotation> $L=$</annotation>\u0000 </semantics></math>3.0) and Seattle (NLK, <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>L</mi>\u0000 <mo>=</mo>\u0000 </mrow>\u0000 <annotation> $L=$</annotation>\u0000 </semantics></math>2.9) stations in USA to the receiver installed at ATH. The magnetic local time dependence of EMIC waves showed higher occurrence rates in the dawn sector. In contrast, EMIC waves accompanied by EP were localized in the dusk sector and were likely to occur during geomagnetic substorms. We found that EMIC waves accompanied by EP were associated with the main phase of geomagnetic storms and occurred inside the plasmapause. These results suggest that the EMIC waves that cause EP occur in the overlap region between the ring current and dense cold plasma during the main phase of geomagnetic storms. This is consistent with previous studies describing that the electron resonant energy with EMIC waves is lower in regions with high plasma density.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JA033357","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612424","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}

{"title":"Sub-MeV Electron Precipitation Driven by EMIC Waves in Plasmaspheric Plumes at High L Shells","authors":"Murong Qin,&nbsp;Wen Li,&nbsp;Yukitoshi Nishimura,&nbsp;Sheng Huang,&nbsp;Qianli Ma,&nbsp;Miroslav Hanzelka,&nbsp;Luisa Capannolo,&nbsp;Xiao-Chen Shen,&nbsp;Vassilis Angelopoulos,&nbsp;Xin An,&nbsp;Anton V. Artemyev,&nbsp;Longzhi Gan","doi":"10.1029/2025JA033756","DOIUrl":"https://doi.org/10.1029/2025JA033756","url":null,"abstract":"<p>Electromagnetic ion cyclotron (EMIC) waves are known to be efficient for precipitating &gt;1 MeV electrons from the magnetosphere into the upper atmosphere. Despite considerable evidence showing that EMIC-driven electron precipitation can extend down to sub-MeV energies, the precise physical mechanism driving sub-MeV electron precipitation remains an active area of investigation. In this study, we present an electron precipitation event observed by ELFIN CubeSats on 11 January 2022, exclusively at sub-MeV energy at <i>L</i> ∼ 8–10.5, where trapped MeV electrons were nearly absent. The THEMIS satellites observed conjugate H-band and He-band EMIC waves and hiss waves in plasmaspheric plumes near the magnetic equator. Quasi-linear diffusion results demonstrate that the observed He-band EMIC waves, with a high ratio of plasma to electron cyclotron frequency, can drive electron precipitation down to ∼400 keV. Our findings suggest that exclusive sub-MeV precipitation (without concurrent MeV precipitation) can be associated with EMIC waves, especially in the plume region at high <i>L</i> shells.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612365","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}

{"title":"Ion Moment Variability Across Substorm Phases: Statistical Insights","authors":"Sanjay Kumar,&nbsp;Tuija I. Pulkkinen,&nbsp;T. Pitkänen","doi":"10.1029/2024JA032953","DOIUrl":"https://doi.org/10.1029/2024JA032953","url":null,"abstract":"&lt;p&gt;In this study, we analyze 5 years of THEMIS and MMS mission data to statistically investigate the distribution of earthward and tailward ion flows during three substorm phases in Earth's magnetotail plasma sheet. The average flow patterns reveal primarily slow sunward and occasional fast tailward convection throughout all substorm phases. Most earthward flows in the plasma sheet had speeds around 35 km/s within the region &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;X&lt;/mi&gt;\u0000 &lt;mo&gt;&gt;&lt;/mo&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;15&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&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;annotation&gt; $X &gt; -15 {R}_{E}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, as observed by THEMIS, while peak velocities reached up to 350 km/s in areas where &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;X&lt;/mi&gt;\u0000 &lt;mo&gt;&lt;&lt;/mo&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;15&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&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;annotation&gt; $X&lt; -15 {R}_{E}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, as observed by MMS-1. Tailward flows showed velocities near 30 km/s earthward of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;X&lt;/mi&gt;\u0000 &lt;mo&gt;≈&lt;/mo&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;15&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $Xapprox -15$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, according to THEMIS, with peak velocities of 300 km/s in the region &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;X&lt;/mi&gt;\u0000 &lt;mo&gt;&gt;&lt;/mo&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;15&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&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;annotation&gt; $X &gt; -15 {R}_{E}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, based on MMS-1 data. Dusk-dawn &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;V&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;⊥&lt;/mo&gt;\u0000 &lt;mi&gt;y&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $left({V}_{perp y}right)$&lt;/annotation&gt;\u0000 ","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JA032953","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612362","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}

{"title":"Radial Diffusion Driven by Spatially Localized ULF Waves in the Earth's Magnetosphere","authors":"Adnane Osmane,&nbsp;Jasmine K. Sandhu,&nbsp;Tom Elsden,&nbsp;Oliver Allanson,&nbsp;Lucile Turc","doi":"10.1029/2024JA033393","DOIUrl":"https://doi.org/10.1029/2024JA033393","url":null,"abstract":"<p>Ultra-Low Frequency (ULF) waves are critical drivers of particle acceleration and loss in the Earth's magnetosphere. While statistical models of ULF-induced radial transport have traditionally assumed that the waves are uniformly distributed across magnetic local time (MLT), decades of observational evidence show significant MLT localization of ULF waves in the Earth's magnetosphere. This study presents, for the first time, a quasi-linear radial diffusion coefficient accounting for localized ULF waves. Our results reveal that when ULF waves cover more than 30% of the MLT, the radial diffusion efficiency is comparable to that of uniform wave distributions. However, when ULF waves are confined within 10% of the drift orbit, the transport coefficient is enhanced by 10%–25%, indicating that narrowly localized ULF waves are efficient drivers of radial diffusion.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612589","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}

{"title":"Magnetospheric Cold Plasma Diagnostics Using High Altitude GNSS Signals","authors":"D. M. Malaspina,&nbsp;P. Axelrad,&nbsp;J. Goldstein,&nbsp;R. Nikoukar,&nbsp;D. Rowland,&nbsp;S. Fantinato,&nbsp;E. Miotti","doi":"10.1029/2024JA033426","DOIUrl":"https://doi.org/10.1029/2024JA033426","url":null,"abstract":"<p>The plasmasphere is a key component of Earth's magnetosphere, regulating numerous energy transfer processes. The plasmasphere is also a cold multi-species plasma. Tracing differences in dynamics between low and high mass cold ions is important for identifying the processes that drive plasmaspheric evolution. At the same time, measurements of cold ion fractional composition within the plasmasphere are sparse and challenging to obtain. Seeking to overcome this challenge, this work presents a novel concept for combining extreme ultraviolet (EUV) photon imaging and Global Navigation Satellite System (GNSS) pseudorange observations to measure cold ion fractional composition throughout the plasmasphere. The feasibility of this concept is demonstrated using a model plasmaspheric density structure combined with known properties of GNSS transmitters and signals. Implementation of this measurement concept on a future space mission has the potential to enable significant new progress understanding processes that drive plasmaspheric and, extension magnetospheric dynamics.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JA033426","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595223","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}

{"title":"Effects of Upstream Drivers on Magnetic Topology at Venus","authors":"Shaosui Xu,&nbsp;Rudy A. Frahm,&nbsp;Yingjuan Ma,&nbsp;Janet G. Luhmann,&nbsp;David L. Mitchell,&nbsp;Moa Persson,&nbsp;Robin Ramstad","doi":"10.1029/2024JA033613","DOIUrl":"https://doi.org/10.1029/2024JA033613","url":null,"abstract":"<p>Although Venus appears to present a predominantly ionospheric obstacle to the solar wind, the magnetic connectivity between the solar wind and the Venus ionosphere, or magnetic topology, is important for characterizing the Venus space environment. In particular, magnetic connectivity is relevant to the magnetization state of the ionosphere, particle precipitation into the atmosphere causing ionization and auroral emissions, and planetary ion escape at Venus. The spatial distributions of different magnetic topologies were statistically analyzed, with some unexpected results. Here, we build on those results by investigating how the external factors of solar cycle phase and upstream conditions affect the occurrence rates of the three magnetic topologies and consider their implications regarding the state of Venus's induced magnetosphere. We find that both the solar cycle phase and upstream dynamic pressure variations control its expansion or contraction. Under solar minimum conditions, the interplanetary magnetic field (IMF) more deeply penetrates into the collisional atmosphere, increasing the occurrence rates of open and closed topologies at low altitudes and in Venus's wake. We also find hemispheric differences in the occurrences of dayside-connected and nightside-connected open fields, likely related to mass loading of the near-Venus plasma environment by planetary pickup ions.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595221","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}

{"title":"Modeling of Three-Dimensional Structure and Dynamics of the Large-Scale Sporadic E Layers Over East Asia","authors":"Lihui Qiu,&nbsp;Huixin Liu","doi":"10.1029/2024JA033270","DOIUrl":"https://doi.org/10.1029/2024JA033270","url":null,"abstract":"<p>Sporadic E (Es) layers are thin layers of concentrated metallic ions in the mesosphere and lower thermosphere region. Their occurrence can cause the uneven distribution of plasma density and affects the performance of the Global Navigation Satellite System and high/very high frequency radio communications. Currently, the three-dimensional (3-D) Es layer structure and evolution process have not yet been fully understood. Using the Fe⁺ layer as a proxy for Es layer, in this study, we investigated the structural and dynamic characteristics of the large-scale Es layers extending thousands of kilometers over East Asia by using a 3-D Es layer numerical model driven by neutral winds from the Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension model. The simulation results show that the Es layer is a tilted blanket rather than a narrow flat band. In addition, the Es layers mainly occur in the 3-D spatial position of the convergent vertical wind shear. The apparent horizontal velocity (∼300–400 m/s) of Es structure is mostly westward and northward, which is different from the ion drift velocity (∼100 m/s). This indicates that Es structure can develop rapidly over a large area simultaneously rather than only drifting from one location to the next. This study systematically analyzed the physics of the 3-D Es layer, which can be helpful for understanding the Es horizontal structure and dynamics recorded by different instruments, such as satellites and global navigation satellite system receiver networks.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JA033270","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595222","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}

{"title":"Nonlinear Effects of Ring Current Protons: Impacts of EMIC Wave Amplitude, Frequency, and Propagation Angle","authors":"Su Zhou,&nbsp;Xiaoli Luan,&nbsp;Shangchun Teng,&nbsp;Zhiwei Wang,&nbsp;Shengting Zhu","doi":"10.1029/2024JA033593","DOIUrl":"https://doi.org/10.1029/2024JA033593","url":null,"abstract":"<p>Nonlinear cyclotron resonance is known to cause the scattering of ring current protons to deviate from the predictions of quasi-linear theory, when wave-induced motion dominates over adiabatic motion. This study employed a test-particle simulation to investigate the nonlinear processes of ring current protons and their dependence on the amplitude, frequency, and wave normal angle <i>ψ</i> of electromagnetic ion cyclotron (EMIC) waves. As the equatorial pitch angle α_eq increases, proton motion becomes dominated by the wave's electromagnetic force and responds nonlinearly. When wave-induced motion and adiabatic motion become comparable, the superposition of nonlinear phase trapping and phase bunching leads to complex oscillations in both the test-particle advection and diffusion coefficients. The nonlinear behavior becomes pronounced when the wave amplitude increases significantly. As the wave frequency increases, EMIC waves can nonlinearly interact with lower energy protons (i.e., <i>E</i>_k &lt; 10 keV). Furthermore, oblique EMIC waves tend to produce less significant nonlinear behavior compared to parallel EMIC waves. Increasing the wave normal angle causes the nonlinear regime (i.e., the number of protons responding nonlinearly) in the E_k−α_eq plane to shrink, and the regime changes discontinuously with respect to α_eq. We propose that the characteristics of EMIC waves significantly influence the nonlinear behavior of ring current protons and should be considered in the wave-particle interacting processes.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595156","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}

{"title":"Quasi-Thermal Noise Spectroscopy in Magnetized Space Plasma: Theory and Model","authors":"P. Dazzi,&nbsp;K. Issautier,&nbsp;N. Meyer-Vernet,&nbsp;P. Henri,&nbsp;M. M. Martinović","doi":"10.1029/2024JA033325","DOIUrl":"https://doi.org/10.1029/2024JA033325","url":null,"abstract":"<p>The quasi-thermal noise measured by an electric antenna is routinely used to characterize space plasmas, mainly measuring the electrons' properties. To employ this diagnostic technique, instrumental models are required to turn the instrumental output into physically meaningful measurements. Such models have been developed mainly under the assumption that no magnetic field is present in the plasma. This limit case is not met in planetary magnetospheres, for example, Earth, Mercury. The latter is the objective of the European Space Agency/Japan Aerospace Exploration Agency BepiColombo mission, that has a dedicated quasi-thermal noise experiment. The aim of this work is to extend the current state-of-the-art in quasi-thermal noise modeling by taking into account the magnetic field, therefore providing a plasma diagnostic in this magnetized regime. To achieve this goal, we developed a model for the quasi-thermal noise in a magnetized plasma. We explore four cases: for a Maxwellian and double Maxwellian electron distributions, both in the collisionless limit and in the presence of weak electron-neutral collisions. Our model is validated against known behaviors of the magnetized quasi-thermal noise spectrum, including: the characteristic frequency of maxima and minima, the modulation from the antenna spinning around the magnetic field, the electron temperature(s) influence. We explored parameter ranges that were not accessible to previous quasi-thermal noise models, in particular the high magnetization regime. The model we developed will enable using quasi-thermal noise experiments for the diagnostic of magnetospheric space plasmas, including but not limited to the Hermean and terrestrial magnetospheres, with foreseen applications to future space missions.</p>","PeriodicalId":15894,"journal":{"name":"Journal of Geophysical Research: Space Physics","volume":"130 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595157","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}