arXiv - PHYS - Space Physics最新文献_第2页

Applications of Atomic Data to Studies of the Sun 原子数据在太阳研究中的应用

arXiv - PHYS - Space Physics Pub Date : 2024-09-13 DOI: arxiv-2409.09166

Peter R. Young

引用次数: 0

First results from a low cost software defined radio system monitoring VHF equatorial ionospheric scintillations in the Indian sector 监测印度扇区甚高频赤道电离层闪烁的低成本软件无线电系统的初步成果

arXiv - PHYS - Space Physics Pub Date : 2024-09-12 DOI: arxiv-2409.07758

Jishnu N. Thekkeppattu

{"title":"First results from a low cost software defined radio system monitoring VHF equatorial ionospheric scintillations in the Indian sector","authors":"Jishnu N. Thekkeppattu","doi":"arxiv-2409.07758","DOIUrl":"https://doi.org/arxiv-2409.07758","url":null,"abstract":"Scintillations of radio frequency signals due to the ionosphere, despite\u0000having been studied for decades, is still an active area of research. Of\u0000particular interest is the scintillations near the geomagnetic equator, where\u0000such scintillations can be strong enough to cause disruptions to satellite\u0000communications. In this paper, a low cost system to monitor VHF scintillations\u0000is described. The system called the Personal Ionospheric Experiment (PIE) makes\u0000use of a widely available software defined radio (SDR) to perform the\u0000measurements. The use of an SDR vastly enhances the flexibility, especially in\u0000environments with non-negligible radio frequency interference (RFI). A simple\u0000technique to effectively subtract out transient RFI commonly found in radio\u0000data is detailed, and tested with data collected over several months. The\u0000utility of the proposed system is demonstrated with the analysis of a\u0000night-time scintillation patch; a few daytime scintillations are also reported.\u0000Therefore this paper demonstrates the feasibility of conducting useful low-cost\u0000radio science experiments in semi-urban locations with RFI, encouraging similar\u0000citizen science initiatives.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178382","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

The April 2023 SYM-H = -233 nT Geomagnetic Storm: A Classical Event 2023 年 4 月 SYM-H = -233 nT 地磁暴：经典事件

arXiv - PHYS - Space Physics Pub Date : 2024-09-12 DOI: arxiv-2409.08118

Rajkumar Hajra, Bruce Tsatnam Tsurutani, Quanming Lu, Richard B. Horne, Gurbax Singh Lakhina, Xu Yang, Pierre Henri, Aimin Du, Xingliang Gao, Rongsheng Wang, San Lu

{"title":"The April 2023 SYM-H = -233 nT Geomagnetic Storm: A Classical Event","authors":"Rajkumar Hajra, Bruce Tsatnam Tsurutani, Quanming Lu, Richard B. Horne, Gurbax Singh Lakhina, Xu Yang, Pierre Henri, Aimin Du, Xingliang Gao, Rongsheng Wang, San Lu","doi":"arxiv-2409.08118","DOIUrl":"https://doi.org/arxiv-2409.08118","url":null,"abstract":"The 23-24 April 2023 double-peak (SYM-H intensities of -179 and -233 nT)\u0000intense geomagnetic storm was caused by interplanetary magnetic field southward\u0000component Bs associated with an interplanetary fast-forward shock-preceded\u0000sheath (Bs of 25 nT), followed by a magnetic cloud (MC) (Bs of 33 nT),\u0000respectively. At the center of the MC, the plasma density exhibited an order of\u0000magnitude decrease, leading to a sub-Alfvenic solar wind interval for ~2.1 hr.\u0000Ionospheric Joule heating accounted for a significant part (~81%) of the\u0000magnetospheric energy dissipation during the storm main phase. Equal amount of\u0000Joule heating in the dayside and nightside ionosphere is consistent with the\u0000observed intense and global-scale DP2 (disturbance polar) currents during the\u0000storm main phase. The sub-Alfvenic solar wind is associated with disappearance\u0000of substorms, a sharp decrease in Joule heating dissipation, and reduction in\u0000electromagnetic ion cyclotron wave amplitude. The shock/sheath compression of\u0000the magnetosphere led to relativistic electron flux losses in the outer\u0000radiation belt between L* = 3.5 and 5.5. Relativistic electron flux\u0000enhancements were detected in the lower L* < 3.5 region during the storm main\u0000and recovery phases. Equatorial ionospheric plasma anomaly structures are found\u0000to be modulated by the prompt penetration electric fields. Around the anomaly\u0000crests, plasma density at ~470 km altitude and altitude-integrated ionospheric\u0000total electron content are found to increase by ~60% and ~80%, with ~33% and\u0000~67% increases in their latitudinal extents compared to their quiet-time\u0000values, respectively.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178383","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

Size distribution of small grains in the inner zodiacal cloud 内黄道带云中小颗粒的粒度分布

arXiv - PHYS - Space Physics Pub Date : 2024-09-11 DOI: arxiv-2409.07411

J. R. Szalay, P. Pokorný, D. M. Malaspina

{"title":"Size distribution of small grains in the inner zodiacal cloud","authors":"J. R. Szalay, P. Pokorný, D. M. Malaspina","doi":"arxiv-2409.07411","DOIUrl":"https://doi.org/arxiv-2409.07411","url":null,"abstract":"The Parker Solar Probe (PSP) spacecraft has transited the inner-most regions\u0000of the zodiacal cloud and detects impacts to the spacecraft body via its\u0000electric field instrument. Multiple dust populations have been proposed to\u0000explain the PSP dust impact rates. PSP's unique orbit allows us to identify a\u0000region where the impact rates are likely dominated by $alpha$-meteoroids,\u0000small zodiacal grains on approximately circular, bound orbits. From the\u0000distribution of voltage signals generated by dust impacts to PSP in this\u0000region, we find the cumulative mass index for grains with radii of\u0000$sim$0.6-1.4 $mu$m (masses of $3times10^{-15}$ to $3times10^{-14}$ kg) to\u0000be $alpha = 1.1 pm 0.3$ from 0.1-0.25 $R_odot$. $alpha$ increases toward\u0000the Sun, with even smaller fragments generated closer to the Sun. The derived\u0000size distribution is steeper than previously estimated, and in contrast to\u0000expectations we find most of the dust mass resides in the smallest fragments\u0000and not in large grains inside 0.15 au. As the inner-most regions of the\u0000zodiacal cloud are likely collisionally evolved, these results place new\u0000constraints how the solar system's zodiacal cloud and by extension\u0000astrophysical debris disks are partitioned in mass.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178388","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

Dependence of the Solar Wind Plasma Density on Moderate Geomagnetic Activity Elucidated by Potential Learning 通过电位学习阐明太阳风等离子体密度与中度地磁活动的关系

arXiv - PHYS - Space Physics Pub Date : 2024-09-11 DOI: arxiv-2409.07073

Ryozo Kitajima, Motoharu Nowada, Ryotaro Kamimura

{"title":"Dependence of the Solar Wind Plasma Density on Moderate Geomagnetic Activity Elucidated by Potential Learning","authors":"Ryozo Kitajima, Motoharu Nowada, Ryotaro Kamimura","doi":"arxiv-2409.07073","DOIUrl":"https://doi.org/arxiv-2409.07073","url":null,"abstract":"The relationship between a moderate level of geomagnetic activity,\u0000represented by the Kp index (2- - 5+), and solar wind conditions were revealed\u0000based on Potential Learning (PL), and dependence of particular solar wind\u0000plasma density (NP) on moderate geomagnetic conditions was discussed. It has\u0000poorly been understood from what stage of geomagnetic activity NP begins to\u0000control the Kp level. Previously, PL succeeded to extract the most influential\u0000solar wind parameters at an extremely low (0 - 1+) and high (6- - 9) Kp ranges\u0000under southward interplanetary magnetic field (IMF) conditions. The IMF three\u0000components, solar wind flow speed (VX), and NP obtained from the 21-year OMNI\u0000solar wind database were used as the PL input parameters. PL extracted VX as\u0000the most significant parameter for the moderate Kp level under southward IMF\u0000conditions and NP is the second most influential parameter. Based on the\u0000examination of the statistical relationship between VX and NP under extremely\u0000low, high, and moderate Kp levels using the PL database, geomagnetic conditions\u0000remain high while NP becomes large, even if VX decreases (or remains similar).\u0000This shows that both VX and NP govern geomagnetic activity, following the\u0000relational equation between Kp and the solar wind plasma parameter. Based on\u0000the relation between VX and NP clarified by PL and incidental statistical\u0000studies using PL input data, we also revealed that NP begins to affect the Kp\u0000level from moderate geomagnetic activity level. These results suggest that even\u0000under southward IMF conditions, the geomagnetic activity might be influenced by\u0000fast (slow) VX and low (high) NP. Our results would greatly help understand\u0000general relationship between solar wind conditions and geomagnetic activity\u0000under various IMF conditions, and forecast the geomagnetic activity under\u0000extreme solar wind conditions.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223603","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

A Unified Phenomenology of Ion Heating in Low-$β$ Plasmas: Test-Particle Simulations 低-$β$等离子体中离子加热的统一现象学：测试粒子模拟

arXiv - PHYS - Space Physics Pub Date : 2024-09-11 DOI: arxiv-2409.07015

Zade Johnston, Jonathan Squire, Romain Meyrand

引用次数: 0

Contemporaneous Appearances of Local-Scale Auroral Spiral and Global-Scale Transpolar Arc: Changes of Auroras and Field-Aligned Current Profiles Before a Substorm and After Its Recovery Phase 地方尺度极光螺旋和全球尺度跨极弧的同时出现：次风暴前和恢复阶段后极光和场对准洋流剖面的变化

arXiv - PHYS - Space Physics Pub Date : 2024-09-10 DOI: arxiv-2409.06389

Motoharu Nowada, Yukinaga Miyashita, Aoi Nakamizo, Noora Partamies, Quan-Qi Shi

{"title":"Contemporaneous Appearances of Local-Scale Auroral Spiral and Global-Scale Transpolar Arc: Changes of Auroras and Field-Aligned Current Profiles Before a Substorm and After Its Recovery Phase","authors":"Motoharu Nowada, Yukinaga Miyashita, Aoi Nakamizo, Noora Partamies, Quan-Qi Shi","doi":"arxiv-2409.06389","DOIUrl":"https://doi.org/arxiv-2409.06389","url":null,"abstract":"Local vortex-structured auroral spiral and a large-scale transpolar arc (TPA)\u0000were contemporaneously observed by the Polar ultraviolet imager (UVI), when a\u0000substorm almost recovered. The TPA grew along the dawnside auroral oval from\u0000the nightside to the dayside (oval-aligned TPA), and a chain of multiple\u0000auroral spots and spiral were located azimuthally near the poleward edge of the\u0000nightside auroral oval. Contemporaneous appearances of the TPA and the auroral\u0000spiral can be seen after the spiral appeared alone. Polar also detected the\u0000oval-aligned TPA and another dawnside TPA with the nightside end distorted\u0000toward the premidnight sector (J-shaped TPA) before and after the spiral's\u0000formation, respectively. To examine these associated magnetotail structures, we\u0000performed global magnetohydrodynamic (MHD) simulations, based on two different\u0000types of code, BAT-S-RUS and improved REPPU, and examined how the field-aligned\u0000current (FAC) profiles varied in association with changes of the auroral form\u0000to TPA and/or auroral spiral. Global MHD simulations with the two different\u0000types of code can reproduce the TPAs and the associated FAC structures in the\u0000magnetotail. The auroral spiral and its nightside FAC profile, however, were\u0000not formed in both simulations, suggesting that its formation process cannot be\u0000treated within an MHD framework but is closely related to some kinetic process.\u0000When the J-shaped TPA and the auroral spiral contemporaneously appeared, the\u0000two MHD simulations could not reproduce the TPA, spiral and their associated\u0000magnetotail FAC structures, also advocating that a kinetic effect related to\u0000the spiral formation might prevent the TPA occurrence.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178386","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

Waste Heat and Habitability: Constraints from Technological Energy Consumption 废热与宜居性：技术能源消耗的制约因素

arXiv - PHYS - Space Physics Pub Date : 2024-09-09 DOI: arxiv-2409.06737

Amedeo Balbi, Manasvi Lingam

{"title":"Waste Heat and Habitability: Constraints from Technological Energy Consumption","authors":"Amedeo Balbi, Manasvi Lingam","doi":"arxiv-2409.06737","DOIUrl":"https://doi.org/arxiv-2409.06737","url":null,"abstract":"Waste heat production represents an inevitable consequence of energy\u0000conversion as per the laws of thermodynamics. Based on this fact, by using\u0000simple theoretical models, we analyze constraints on the habitability of\u0000Earth-like terrestrial planets hosting putative technological species and\u0000technospheres characterized by persistent exponential growth of energy\u0000consumption and waste heat generation: in particular, we quantify the\u0000deleterious effects of rising surface temperature on biospheric processes and\u0000the eventual loss of liquid water. Irrespective of whether these sources of\u0000energy are ultimately stellar or planetary (e.g., nuclear, fossil fuels) in\u0000nature, we demonstrate that the loss of habitable conditions on such\u0000terrestrial planets may be expected to occur on timescales of $lesssim 1000$\u0000years, as measured from the start of the exponential phase, provided that the\u0000annual growth rate of energy consumption is of order $1%$. We conclude by\u0000discussing the types of evolutionary trajectories that might be feasible for\u0000industrialized technological species, and sketch the ensuing implications for\u0000technosignature searches.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178385","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

Structure and dynamics of the magnetopause and its boundary layers 磁层顶及其边界层的结构和动力学

arXiv - PHYS - Space Physics Pub Date : 2024-09-09 DOI: arxiv-2409.05262

Hiroshi Hasegawa

{"title":"Structure and dynamics of the magnetopause and its boundary layers","authors":"Hiroshi Hasegawa","doi":"arxiv-2409.05262","DOIUrl":"https://doi.org/arxiv-2409.05262","url":null,"abstract":"The magnetopause is the key region in space for the transfer of solar wind\u0000mass, momentum, and energy into the magnetosphere. During the last decade, our\u0000understanding of the structure and dynamics of Earth's magnetopause and its\u0000boundary layers has advanced considerably; thanks largely to the advent of\u0000multi-spacecraft missions such as Cluster and THEMIS. Moreover, various types\u0000of physics-based techniques have been developed for visualizing two- or\u0000three-dimensional plasma and field structures from data taken by one or more\u0000spacecraft, providing a new approach to the analysis of the spatiotemporal\u0000properties of magnetopause processes, such as magnetic reconnection and the\u0000Kelvin-Helmholtz instability (KHI). Information on the size, shape,\u0000orientation, and evolution of magnetic flux ropes or flow vortices generated by\u0000those processes can be extracted from in situ measurements. Observations show\u0000that magnetopause reconnection can be globally continuous for both southward\u0000and northward interplanetary magnetic field (IMF) conditions, but even under\u0000such circumstances, more than one X-line may exist within a certain\u0000(low-latitude or high-latitude) portion on the magnetopause and some X-lines\u0000may retreat anti-sunward. The potential global effects of such behavior are\u0000discussed. An overview is also given of the identification, excitation,\u0000evolution, and possible consequences of the magnetopause KHI: there is evidence\u0000for nonlinear KHI growth and associated vortex-induced reconnection under\u0000northward IMF. Observation-based estimates indicate that reconnection tailward\u0000of both polar cusps can be the dominant mechanism for solar wind plasma entry\u0000into the dayside magnetosphere under northward IMF. However, the mechanism by\u0000which the transferred plasma is transported into the central portion of the\u0000magnetotail, and the role of magnetopause processes in this transport remain\u0000unclear.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178387","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

Magnetospheric control of ionospheric TEC perturbations via whistler-mode and ULF waves 磁层通过惠斯勒模式和超低频波控制电离层 TEC 扰动

arXiv - PHYS - Space Physics Pub Date : 2024-09-08 DOI: arxiv-2409.05168

Yangyang Shen, Olga P. Verkhoglyadova, Anton Artemyev, Michael D. Hartinger, Vassilis Angelopoulos, Xueling Shi, Ying Zou

{"title":"Magnetospheric control of ionospheric TEC perturbations via whistler-mode and ULF waves","authors":"Yangyang Shen, Olga P. Verkhoglyadova, Anton Artemyev, Michael D. Hartinger, Vassilis Angelopoulos, Xueling Shi, Ying Zou","doi":"arxiv-2409.05168","DOIUrl":"https://doi.org/arxiv-2409.05168","url":null,"abstract":"The weakly ionized plasma in the Earth's ionosphere is controlled by a\u0000complex interplay between solar and magnetospheric inputs from above,\u0000atmospheric processes from below, and plasma electrodynamics from within. This\u0000interaction results in ionosphere structuring and variability that pose major\u0000challenges for accurate ionosphere prediction for global navigation satellite\u0000system (GNSS) related applications and space weather research. The ionospheric\u0000structuring and variability are often probed using the total electron content\u0000(TEC) and its relative perturbations (dTEC). Among dTEC variations observed at\u0000high latitudes, a unique modulation pattern has been linked to magnetospheric\u0000ultra low frequency (ULF) waves, yet its underlying mechanisms remain unclear.\u0000Here using magnetically-conjugate observations from the THEMIS spacecraft and a\u0000ground-based GPS receiver at Fairbanks, Alaska, we provide direct evidence that\u0000these dTEC modulations are driven by magnetospheric electron precipitation\u0000induced by ULF-modulated whistler-mode waves. We observed peak-to-peak dTEC\u0000amplitudes reaching ~0.5 TECU (1 TECU is equal to 10$^6$ electrons/m$^2$) with\u0000modulations spanning scales of ~5--100 km. The cross-correlation between our\u0000modeled and observed dTEC reached ~0.8 during the conjugacy period but\u0000decreased outside of it. The spectra of whistler-mode waves and dTEC also\u0000matched closely at ULF frequencies during the conjugacy period but diverged\u0000outside of it. Our findings elucidate the high-latitude dTEC generation from\u0000magnetospheric wave-induced precipitation, addressing a significant gap in\u0000current physics-based dTEC modeling. Theses results thus improve ionospheric\u0000dTEC prediction and enhance our understanding of magnetosphere-ionosphere\u0000coupling via ULF waves.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178402","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