arXiv - PHYS - Space Physics最新文献_第8页

Deriving the Topological Properties of the Magnetic Field of Coronal Mass Ejections from In Situ Measurements: Techniques 从现场测量推导日冕物质抛射磁场的拓扑特性：技术

arXiv - PHYS - Space Physics Pub Date : 2024-08-08 DOI: arxiv-2408.04608

Nada Al-Haddad, Mitchell Berger

{"title":"Deriving the Topological Properties of the Magnetic Field of Coronal Mass Ejections from In Situ Measurements: Techniques","authors":"Nada Al-Haddad, Mitchell Berger","doi":"arxiv-2408.04608","DOIUrl":"https://doi.org/arxiv-2408.04608","url":null,"abstract":"Coronal mass ejections (CMEs) are magnetized plasma systems with highly\u0000complex magnetic topology and evolution. Methods developed to assess their\u0000magnetic configuration have primarily focused on reconstructing\u0000three-dimensional representations from one-dimensional time series measurements\u0000taken in situ using techniques based on the \"highly twisted magnetic flux rope\"\u0000approximations. However, the magnetic fields of CMEs is know to have more\u0000complicated geometries. Their structure can be quantified using measures of\u0000field line topology, which have been primarily used for solar physics research.\u0000In this work, we introduce a novel technique of directly quantifying the\u0000various form of magnetic helicity within a CME in the interplanetary space\u0000using synthetic in situ measurements. We use a relatively simple\u0000three-dimensional simulation of a CME initiated with a highly-twisted flux\u0000rope. We find that a significant portion of the magnetic helicity near 1~au is\u0000contained in writhe and mutual helicity rather than just in twist. We discuss\u0000the implications of this finding for fitting and reconstruction techniques.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Case studies on pre-eruptive X-class flares using R-value in the lower solar atmosphere 利用太阳低层大气中的 R 值对爆发前 X 级耀斑进行案例研究

arXiv - PHYS - Space Physics Pub Date : 2024-08-07 DOI: arxiv-2408.04018

Shreeyesh Biswal, Marianna B. Korsós, Manolis K. Georgoulis, Alexander Nindos, Spiros Patsourakos, Robertus Erdélyi

{"title":"Case studies on pre-eruptive X-class flares using R-value in the lower solar atmosphere","authors":"Shreeyesh Biswal, Marianna B. Korsós, Manolis K. Georgoulis, Alexander Nindos, Spiros Patsourakos, Robertus Erdélyi","doi":"arxiv-2408.04018","DOIUrl":"https://doi.org/arxiv-2408.04018","url":null,"abstract":"The R-value is a measure of the strength of photospheric magnetic Polarity\u0000Inversion Lines (PILs) in Active Regions (ARs). This work investigates the\u0000possibility of a relation between R-value variations and the occurrence of\u0000X-class flares in ARs, not in the solar photosphere, as usual, but above it in\u0000regions, closer to where flares occur. The modus operandi is to extrapolate the\u0000Solar Dynamic Observatory's (SDO) Helioseismic and Magnetic Imager (HMI)\u0000magnetogram data up to a height of 3.24 Mm above the photosphere and then\u0000compute the R-value based on the extrapolated magnetic field. Recent studies\u0000have shown that certain flare-predictive parameters such as the horizontal\u0000gradient of the vertical magnetic field and magnetic helicity may improve flare\u0000prediction lead times significantly if studied at a specific height range above\u0000the photosphere, called the Optimal Height Range (OHR). Here we define the OHR\u0000as a collection of heights where a sudden but sustained increase in R-value is\u0000found. For the eight case studies discussed in this paper, our results indicate\u0000that it is possible for OHRs to exist in the low solar atmosphere (between 0.36\u0000- 3.24 Mm), where R-value spikes occur 48-68 hrs before the first X-class flare\u0000of an emerging AR. The temporal evolution of R-value before the first X-class\u0000flare for an emerging AR is also found to be distinct from that of non-flaring\u0000ARs. For X-class flares associated with non-emerging ARs, an OHR could not be\u0000found.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Kinetic scales dominated by magnetic helicity in space plasmas 空间等离子体中由磁螺旋主导的动力学尺度

arXiv - PHYS - Space Physics Pub Date : 2024-08-06 DOI: arxiv-2408.03267

A. Bershadskii

引用次数: 0

Characterizing the current systems in the Martian ionosphere 确定火星电离层当前系统的特征

arXiv - PHYS - Space Physics Pub Date : 2024-08-06 DOI: arxiv-2408.03075

Jiawei Gao, Shibang Li, Anna Mittelholz, Zhaojin Rong, Moa Persson, Zhen Shi, Haoyu Lu, Chi Zhang, Xiaodong Wang, Chuanfei Dong, Lucy Klinger, Jun Cui, Yong Wei, Yongxin Pan

{"title":"Characterizing the current systems in the Martian ionosphere","authors":"Jiawei Gao, Shibang Li, Anna Mittelholz, Zhaojin Rong, Moa Persson, Zhen Shi, Haoyu Lu, Chi Zhang, Xiaodong Wang, Chuanfei Dong, Lucy Klinger, Jun Cui, Yong Wei, Yongxin Pan","doi":"arxiv-2408.03075","DOIUrl":"https://doi.org/arxiv-2408.03075","url":null,"abstract":"When the solar wind interacts with the ionosphere of an unmagnetized planet,\u0000it induces currents that form an induced magnetosphere. These currents and\u0000their associated magnetic fields play a pivotal role in controlling the\u0000movement of charged particles, which is essential for understanding the escape\u0000of planetary ions. Unlike the well-documented magnetospheric current systems,\u0000the ionospheric current systems on unmagnetized planets remain less understood,\u0000which constrains the quantification of electrodynamic energy transfer from\u0000stars to these planets. Here, utilizing eight years of data from the Mars\u0000Atmosphere and Volatile EvolutioN (MAVEN) mission, we investigate the global\u0000distribution of ionospheric currents on Mars. We have identified two distinct\u0000current systems in the ionosphere: one aligns with the solar wind electric\u0000field yet exhibits hemispheric asymmetry perpendicular to the electric field\u0000direction; the other corresponds to the flow pattern of annually-averaged\u0000neutral winds. We propose that these two current systems are driven by the\u0000solar wind and atmospheric neutral winds, respectively. Our findings reveal\u0000that Martian ionospheric dynamics are influenced by the neutral winds from\u0000below and the solar wind from above, highlighting the complex and intriguing\u0000nature of current systems on unmagnetized planets.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","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 Plasma Composition of 67P/C-G at different Heliocentric Distances 不同日心距离下的 67P/C-G 等离子体成分建模

arXiv - PHYS - Space Physics Pub Date : 2024-08-05 DOI: arxiv-2408.02338

Sana Ahmed, Vikas Soni

{"title":"Modeling the Plasma Composition of 67P/C-G at different Heliocentric Distances","authors":"Sana Ahmed, Vikas Soni","doi":"arxiv-2408.02338","DOIUrl":"https://doi.org/arxiv-2408.02338","url":null,"abstract":"The Rosetta spacecraft accompanied the comet 67P/C-G for nearly 2 years,\u0000collecting valuable data on the neutral and ion composition of the coma. The\u0000Rosetta Plasma Consortium (RPC) provided continuous measurements of the in situ\u0000plasma density while ROSINA-COPS monitored the neutral composition. In this\u0000work, we aim to estimate the composition of the cometary ionosphere at\u0000different heliocentric distances of the comet. Lauter et al. (2020) derived the\u0000temporal evolution of the volatile sublimation rates for 50 separated time\u0000intervals on the orbit of 67P/C-G using the COPS and DFMS data. We use these\u0000sublimation rates as inputs in a multifluid chemical-hydrodynamical model for\u000036 of the time intervals for heliocentric distances < 3 au. We compare the\u0000total ion densities obtained from our models with the local plasma density\u0000measured by the RPC instruments. We find that at the location of the\u0000spacecraft, our modeled ion densities match with the in situ measured plasma\u0000density within factors of 1 - 3 for many of the time intervals. We obtain the\u0000cometocentric distance variation of the ions H2O+ and H3O+ and the ion groups\u0000created respectively by the ionization and protonation of neutral species. We\u0000see that H3O+ is dominant at the spacecraft location for nearly all the time\u0000intervals while ions created due to protonation are dominant at low\u0000cometocentric distances for the intervals near perihelion. We also discuss our\u0000ion densities in the context of their detection by DFMS.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evidence of dual energy transfer driven by magnetic reconnection at sub-ion scales 亚离子尺度磁重联驱动的双能量转移证据

arXiv - PHYS - Space Physics Pub Date : 2024-08-05 DOI: arxiv-2408.02505

Raffaello Foldes, Silvio Sergio Cerri, Raffaele Marino, Enrico Camporeale

引用次数: 0

SEP environment in the inner heliosphere from Solar Orbiter and Parker Solar Probe 太阳轨道器和帕克太阳探测器提供的内日光层中的 SEP 环境

arXiv - PHYS - Space Physics Pub Date : 2024-08-05 DOI: arxiv-2408.02330

Robert F. Wimmer-Schweingruber, Javier Rodriguez-Pacheco, George C. Ho, Christina M. Cohen, Glenn M. Mason, the Solar Orbiter EPD, Parker Solar Probe ISIS teams

引用次数: 0

SLAMS-Propelled Electron Acceleration at High-Mach Number Astrophysical Shocks 高机器数天体物理冲击下的 SLAMS 推动电子加速

arXiv - PHYS - Space Physics Pub Date : 2024-08-04 DOI: arxiv-2408.02084

Vladimir Zeković, Anatoly Spitkovsky, Zachary Hemler

{"title":"SLAMS-Propelled Electron Acceleration at High-Mach Number Astrophysical Shocks","authors":"Vladimir Zeković, Anatoly Spitkovsky, Zachary Hemler","doi":"arxiv-2408.02084","DOIUrl":"https://doi.org/arxiv-2408.02084","url":null,"abstract":"Short Large Amplitude Magnetic Structures (SLAMS) are frequently detected\u0000during spacecraft crossings over the Earth bow shock. We investigate the\u0000existence of such structures at astrophysical shocks, where they could result\u0000from the steepening of cosmic-ray (CR) driven waves. Using kinetic\u0000particle-in-cell simulations, we study the growth of SLAMS and the appearance\u0000of associated transient shocks in the upstream region of quasi-parallel,\u0000non-relativistic, high-Mach number collisionless shocks. We find that\u0000high-energy CRs significantly enhance the transverse magnetic field within\u0000SLAMS, producing highly inclined field lines. As SLAMS are advected towards the\u0000shock, these fields lines form an intermittent superluminal configuration which\u0000traps magnetized electrons at fast shocks. Due to their oscillatory nature,\u0000SLAMS are periodically separated by subluminal gaps with lower transverse\u0000magnetic field strength. In these regions, electrons diffuse and accelerate by\u0000bouncing between the shock and the approaching SLAMS region through a mechanism\u0000that we call quasi-periodic shock acceleration (QSA). We analytically derive\u0000the distribution of electrons accelerated via QSA, $f(p)sim p^{[-4.7,-5.7]}$,\u0000which agrees well with the simulation spectra. We find that the electron power\u0000law remains steep until the end of our longest runs, providing a possible\u0000explanation for the steep electron spectra observed at least up to GeV energies\u0000in young and fast supernova remnants.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Electrostatic Waves and Electron Holes in Simulations of Low-Mach Quasi-Perpendicular Shocks 低速准垂直冲击模拟中的静电波和电子洞

arXiv - PHYS - Space Physics Pub Date : 2024-08-03 DOI: arxiv-2408.01699

Artem Bohdan, Aaron Tran, Lorenzo Sironi, Lynn B. Wilson III

{"title":"Electrostatic Waves and Electron Holes in Simulations of Low-Mach Quasi-Perpendicular Shocks","authors":"Artem Bohdan, Aaron Tran, Lorenzo Sironi, Lynn B. Wilson III","doi":"arxiv-2408.01699","DOIUrl":"https://doi.org/arxiv-2408.01699","url":null,"abstract":"Collisionless low Mach number shocks are abundant in astrophysical and space\u0000plasma environments, exhibiting complex wave activity and wave-particle\u0000interactions. In this paper, we present 2D Particle-in-Cell (PIC) simulations\u0000of quasi-perpendicular nonrelativistic ($vsh approx (5500-22000)$ km/s) low\u0000Mach number shocks, with a specific focus on studying electrostatic waves in\u0000the shock ramp and the precursor regions. In these shocks, an ion-scale oblique\u0000whistler wave creates a configuration with two hot counter-streaming electron\u0000beams, which drive unstable electron acoustic waves (EAWs) that can turn into\u0000electrostatic solitary waves (ESWs) at the late stage of their evolution. By\u0000conducting simulations with periodic boundaries, we show that EAW properties\u0000agree with linear dispersion analysis. The characteristics of ESWs in shock\u0000simulations, including their wavelength and amplitude, depend on the shock\u0000velocity. When extrapolated to shocks with realistic velocities ($vsh approx\u0000300$ km/s), the ESW wavelength is reduced to one tenth of the electron skin\u0000depth and the ESW amplitude is anticipated to surpass that of the quasi-static\u0000electric field by more than a factor of 100. These theoretical predictions may\u0000explain a discrepancy, between PIC and satellite measurements, in the relative\u0000amplitude of high- and low-frequency electric field fluctuations.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141946834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

MHD waves in homogeneous and continuously stratified atmospheres 均质和连续分层大气中的 MHD 波

arXiv - PHYS - Space Physics Pub Date : 2024-08-02 DOI: arxiv-2408.01591

Paul S. Cally, Thomas J. Bogdan

引用次数: 0