arXiv - PHYS - Space Physics最新文献_第9页

A case study on the impact of interplanetary coronal mass ejection on the Martian O(1S) 557.7 nm dayglow emission using ExoMars TGO/NOMAD-UVIS observations: First Results 利用 ExoMars TGO/NOMAD-UVIS 观测数据研究行星际日冕物质抛射对火星 O(1S) 557.7 nm 日辉发射的影响：初步结果

arXiv - PHYS - Space Physics Pub Date : 2024-08-02 DOI: arxiv-2408.01045

Aadarsh Raj Sharma, Lot Ram, Harshaa Suhaag, Dipjyoti Patgiri, Lauriane Soret, Jean-Claude Gerard, Ian R. Thomas, Ann Carine Vandaele, Sumanta Sarkhel

{"title":"A case study on the impact of interplanetary coronal mass ejection on the Martian O(1S) 557.7 nm dayglow emission using ExoMars TGO/NOMAD-UVIS observations: First Results","authors":"Aadarsh Raj Sharma, Lot Ram, Harshaa Suhaag, Dipjyoti Patgiri, Lauriane Soret, Jean-Claude Gerard, Ian R. Thomas, Ann Carine Vandaele, Sumanta Sarkhel","doi":"arxiv-2408.01045","DOIUrl":"https://doi.org/arxiv-2408.01045","url":null,"abstract":"We report, for the first time, the impact of an interplanetary coronal mass\u0000ejection (ICME) on the recently discovered O($^1$S) 557.7 nm dayglow emission\u0000in the Martian atmosphere. Although there are only a few studies on the\u0000seasonal variation are available in the literature, the impact of ICME on 557.7\u0000nm dayglow emission has not been investigated so far. Using the instruments\u0000aboard ExoMars-TGO and MAVEN spacecrafts, we show that the primary emission\u0000peak (75-80 km) remains unaffected during the ICME event compared to\u0000quiet-times. However, a noticeable enhancement has been observed in the\u0000brightness of secondary emission peak (110-120 km) and the upper altitude\u0000region (140-180 km). The enhancement is attributed to the increased solar\u0000electrons and X-ray fluxes, augmenting the electron-impact process and causing\u0000the enhancement in the brightness. These analyses have an implication to\u0000comprehend the role of intense solar transients like ICME on the Martian\u0000dayglow emissions.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969667","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

Whistler waves in the young solar wind: statistics of amplitude and propagation direction from Parker Solar Probe Encounters 1-11 年轻太阳风中的惠斯勒波：帕克太阳探测器第1-11次相遇的振幅和传播方向统计数据

arXiv - PHYS - Space Physics Pub Date : 2024-08-01 DOI: arxiv-2408.00736

Kyung-Eun Choi, Oleksiy Agapitov, Lucas Colomban, John W. Bonnell, Forrest Mozer, Richard D. Sydora, Nour Raouafi, Thierry Dudok de Wit

{"title":"Whistler waves in the young solar wind: statistics of amplitude and propagation direction from Parker Solar Probe Encounters 1-11","authors":"Kyung-Eun Choi, Oleksiy Agapitov, Lucas Colomban, John W. Bonnell, Forrest Mozer, Richard D. Sydora, Nour Raouafi, Thierry Dudok de Wit","doi":"arxiv-2408.00736","DOIUrl":"https://doi.org/arxiv-2408.00736","url":null,"abstract":"In the interplanetary space solar wind plasma, whistler waves are observed in\u0000a wide range of heliocentric distance (from ~20 solar radii (RS) to Jupiter's\u0000orbit). They are known to interact with solar wind suprathermal electrons\u0000(strahl and halo) and to regulate the solar wind heat flux through scattering\u0000the strahl electrons. We present the results of applying the technique to\u0000determine the whistler wave propagation direction to the spectral data\u0000continuously collected by the FIELDS instruments aboard Parker Solar Probe\u0000(PSP). The technique was validated based on the results obtained from burst\u0000mode magnetic and electric field waveform data collected during Encounter 1. We\u0000estimated the effective length of the PSP electric field antennas (EFI) for a\u0000variety of solar wind conditions in the whistler wave frequency range and\u0000utilized these estimates for determining the whistler wave properties during\u0000PSP Encounters 1-11. Our findings show that (1) the enhancement of the whistler\u0000wave occurrence rate and wave amplitudes observed between 25-35 RS is\u0000predominantly due to the sunward propagating whistler waves population\u0000associated with the switchback-related magnetic dips; (2) the anti-sunward or\u0000counter-propagating cases are observed at 30-40 RS; (3) between 40-50 RS,\u0000sunward and anti-sunward whistlers are observed with comparable occurrence\u0000rates; and (4) almost no sunward or counter-propagating whistlers were observed\u0000at heliocentric distances above 50 RS.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141882644","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

Turbulence, Waves, and Taylor's Hypothesis for Heliosheath Observations 湍流、波浪和泰勒假说对太阳弧观测的影响

arXiv - PHYS - Space Physics Pub Date : 2024-07-31 DOI: arxiv-2407.21673

L. -L. Zhao, G. P. Zank, M. Opher, B. Zieger, H. Li, V. Florinski, L. Adhikari, X. Zhu, M. Nakanotani

{"title":"Turbulence, Waves, and Taylor's Hypothesis for Heliosheath Observations","authors":"L. -L. Zhao, G. P. Zank, M. Opher, B. Zieger, H. Li, V. Florinski, L. Adhikari, X. Zhu, M. Nakanotani","doi":"arxiv-2407.21673","DOIUrl":"https://doi.org/arxiv-2407.21673","url":null,"abstract":"Magnetic field fluctuations measured in the heliosheath by the Voyager\u0000spacecraft are often characterized as compressible, as indicated by a strong\u0000fluctuating component parallel to the mean magnetic field. However, the\u0000interpretation of the turbulence data faces the caveat that the standard Taylor\u0000hypothesis is invalid because the solar wind flow velocity in the heliosheath\u0000becomes subsonic and slower than the fast magnetosonic speed, given the\u0000contributions from hot pickup ions in the heliosheath. We attempt to overcome\u0000this caveat by introducing a 4D frequency wavenumber spectral modeling of\u0000turbulence, which is essentially a decomposition of different wave modes\u0000following their respective dispersion relations. Isotropic Alfven and fast mode\u0000turbulence are considered to represent the heliosheath fluctuations. We also\u0000include two dispersive fast wave modes derived from a three-fluid theory. We\u0000find that (1) magnetic fluctuations in the inner heliosheath are less\u0000compressible than previously thought. An isotropic turbulence spectral model\u0000with about 1/4 in compressible fluctuation power is consistent with the\u0000observed magnetic compressibility in the heliosheath; (2) the hot pickup ion\u0000component and the relatively cold solar wind ions induce two dispersive fast\u0000magnetosonic wave branches in the perpendicular propagation limit. Pickup ion\u0000fast wave may account for the spectral bump near the proton gyrofrequency in\u0000the observable spectrum; (3) it is possible that the turbulence wavenumber\u0000spectrum is not Kolmogorov-like although the observed frequency spectrum has a\u0000-5/3 power law index, depending on the partitioning of power among the various\u0000wave modes, and this partitioning may change with wavenumber.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866370","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

Spurious Solar-Wind Effects on Acceleration Noise in LISA Pathfinder 太阳风对 LISA 探路者加速噪声的杂散影响

arXiv - PHYS - Space Physics Pub Date : 2024-07-31 DOI: arxiv-2407.21774

Arnold Yang, Indie Desiderio-Sloane, Grant David Meadors

{"title":"Spurious Solar-Wind Effects on Acceleration Noise in LISA Pathfinder","authors":"Arnold Yang, Indie Desiderio-Sloane, Grant David Meadors","doi":"arxiv-2407.21774","DOIUrl":"https://doi.org/arxiv-2407.21774","url":null,"abstract":"Spurious solar-wind effects are a potential noise source in the measurements\u0000of the future Laser Interferometer Space Antenna (LISA). Comparative models are\u0000used to predict the possible impact of this noise factor and estimate spurious\u0000solar-wind effects on acceleration noise in LISA Pathfinder (LPF). Data from\u0000NASA's Advanced Composition Explorer (ACE), situated at the L1 Lagrange point,\u0000served as a reliable source of solar-wind data. The data sets were compared\u0000over the 114-day time period from March 1, 2016 to June 23, 2016. To evaluate\u0000these effects, the data from both satellites were formatted, gap-filled, and\u0000adapted for comparison, and a coherence plot comparing the results of the Fast\u0000Fourier Transformations. The coherence plot suggested that solar-wind had a\u0000minuscule effect on the LPF, and higher frequency coherence (LISA's main\u0000observing band) can be attributed to random chance correlation. This result\u0000indicates that measurable correlation due to solar-wind noise over 3-month\u0000timescales can be ruled out as a noise source. This is encouraging, although\u0000another source of noise from the sun, solar irradiance pressure, is estimated\u0000to have a more significant effect and has yet to be analyzed.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866374","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

Toroidal modified Miller-Turner CME model in EUHFORIA: II. Validation and comparison with flux rope and spheromak EUHFORIA 中的环形修正米勒-特纳 CME 模型：II.验证以及与通量绳和球面仪的比较

arXiv - PHYS - Space Physics Pub Date : 2024-07-31 DOI: arxiv-2408.03882

Anwesha Maharana, Luis Linan, Stefaan Poedts, Jasmina Magdalenic

{"title":"Toroidal modified Miller-Turner CME model in EUHFORIA: II. Validation and comparison with flux rope and spheromak","authors":"Anwesha Maharana, Luis Linan, Stefaan Poedts, Jasmina Magdalenic","doi":"arxiv-2408.03882","DOIUrl":"https://doi.org/arxiv-2408.03882","url":null,"abstract":"Rising concerns about the impact of space weather-related disruptions demand\u0000modelling and reliable forecasting of coronal mass ejection (CME) impacts. In\u0000this study, we demonstrate the application of the modified Miller-Turner (mMT)\u0000model implemented in EUropean Heliospheric FORecasting Information Asset\u0000(EUHFORIA), to forecast the geo-effectiveness of observed coronal mass ejection\u0000(CME) events in the heliosphere. The goal is to develop a model that not only\u0000has a global geometry to improve overall forecasting but is also fast enough\u0000for operational space weather forecasting. We test the original full torus\u0000implementation and introduce a new three-fourth Torus version called the\u0000Horseshoe CME model. This new model has a more realistic CME geometry, and it\u0000overcomes the inaccuracies of the full torus geometry. We constrain the torus\u0000geometrical and magnetic field parameters using observed signatures of the CMEs\u0000before, during, and after the eruption. The assessment of the model's\u0000capability to predict the most important Bz component is performed using the\u0000advanced Dynamic Time Warping technique. The Horseshoe model prediction of CME\u0000arrival time and geo-effectiveness for both validation events compare well to\u0000the observations and are weighed with the results obtained with the spheromak\u0000and FRi3D models that were already available in EUHFORIA. The runtime of the\u0000Horseshoe model simulations is close to that of the spheromak model, which is\u0000suitable for operational space weather forecasting. Yet, the capability of the\u0000magnetic field prediction at 1~AU of the Horseshoe model is close to that of\u0000the FRi3D model. In addition, we demonstrate that the Horseshoe CME model can\u0000be used for simulating successive CMEs in EUHFORIA, overcoming a limitation of\u0000the FRi3D model.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969665","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 Interplay Between Collisionless Magnetic Reconnection and Turbulence 无碰撞磁重连接与湍流之间的相互作用

arXiv - PHYS - Space Physics Pub Date : 2024-07-30 DOI: arxiv-2407.20787

J. E. Stawarz, P. A. Muñoz, N. Bessho, R. Bandyopadhyay, T. K. M. Nakamura, S. Eriksson, D. Graham, J. Büchner, A. Chasapis, J. F. Drake, M. A. Shay, R. E. Ergun, H. Hasegawa, Yu. V. Khotyaintsev, M. Swisdak, F. Wilder

{"title":"The Interplay Between Collisionless Magnetic Reconnection and Turbulence","authors":"J. E. Stawarz, P. A. Muñoz, N. Bessho, R. Bandyopadhyay, T. K. M. Nakamura, S. Eriksson, D. Graham, J. Büchner, A. Chasapis, J. F. Drake, M. A. Shay, R. E. Ergun, H. Hasegawa, Yu. V. Khotyaintsev, M. Swisdak, F. Wilder","doi":"arxiv-2407.20787","DOIUrl":"https://doi.org/arxiv-2407.20787","url":null,"abstract":"Alongside magnetic reconnection, turbulence is another fundamental nonlinear\u0000plasma phenomenon that plays a key role in energy transport and conversion in\u0000space and astrophysical plasmas. From a numerical, theoretical, and\u0000observational point of view there is a long history of exploring the interplay\u0000between these two phenomena in space plasma environments; however, recent\u0000high-resolution, multi-spacecraft observations have ushered in a new era of\u0000understanding this complex topic. The interplay between reconnection and\u0000turbulence is both complex and multifaceted, and can be viewed through a number\u0000of different interrelated lenses - including turbulence acting to generate\u0000current sheets that undergo magnetic reconnection (turbulence-driven\u0000reconnection), magnetic reconnection driving turbulent dynamics in an\u0000environment (reconnection-driven turbulence) or acting as an intermediate step\u0000in the excitation of turbulence, and the random diffusive/dispersive nature of\u0000magnetic field lines embedded in turbulent fluctuations enabling so-called\u0000stochastic reconnection. In this paper, we review the current state of\u0000knowledge on these different facets of the interplay between turbulence and\u0000reconnection in the context of collisionless plasmas, such as those found in\u0000many near-Earth astrophysical environments, from a theoretical, numerical, and\u0000observational perspective. Particular focus is given to several key regions in\u0000Earth's magnetosphere - Earth's magnetosheath, magnetotail, and\u0000Kelvin-Helmholtz vortices on the magnetopause flanks - where NASA's\u0000Magnetospheric Multiscale mission has been providing new insights on the topic.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866369","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

Turbulent Energy Conversion Associated with Kinetic Microinstabilities in Earth's Magnetosheath 地球磁鞘中与动能微不稳定性有关的湍流能量转换

arXiv - PHYS - Space Physics Pub Date : 2024-07-30 DOI: arxiv-2407.20844

Harry C. LewisImperial College London, Julia E. StawarzNorthumbria University, Lorenzo MatteiniImperial College London, Luca FranciNorthumbria University, Kristopher G. KleinUniversity of Arizona, Robert T. WicksNorthumbria University, Chadi S. SalemUniversity of California Berkeley, Timothy S. HorburyImperial College London, Joseph H. WangImperial College London

{"title":"Turbulent Energy Conversion Associated with Kinetic Microinstabilities in Earth's Magnetosheath","authors":"Harry C. LewisImperial College London, Julia E. StawarzNorthumbria University, Lorenzo MatteiniImperial College London, Luca FranciNorthumbria University, Kristopher G. KleinUniversity of Arizona, Robert T. WicksNorthumbria University, Chadi S. SalemUniversity of California Berkeley, Timothy S. HorburyImperial College London, Joseph H. WangImperial College London","doi":"arxiv-2407.20844","DOIUrl":"https://doi.org/arxiv-2407.20844","url":null,"abstract":"Plasma in the terrestrial magnetosheath is characterised by very weak\u0000particle-particle collisions, so kinetic microinstabilities are thought to be\u0000responsible for regulating the thermodynamics of the plasma. By exciting\u0000electromagnetic waves, these instabilities redistribute free energy in velocity\u0000space, moulding the velocity distribution function (VDF) into a lower energy\u0000state. In the high-beta magnetosheath, relatively small perturbations to the\u0000VDF can easily excite instabilities compared to in the low-beta inner\u0000heliosphere. Since magnetic fields cannot do work on the particles, electric\u0000fields mediate energy exchange between the electromagnetic field and the bulk\u0000fluid properties of the plasma. We investigate signatures of non-ideal energy\u0000conversion associated with turbulent fluctuations in the context of electron\u0000and ion temperature anisotropy-beta instabilities, utilising over 24 hours of\u0000data spread over 163 distinct intervals of in situ magnetosheath observations\u0000from Magnetospheric Multiscale (MMS). We find that average energy conversion\u0000into fluid flow is enhanced along instability boundaries, suggesting that\u0000turbulence is playing a role in how free energy is redistributed in the plasma.\u0000The work enables a quantification of the energetics which are associated with\u0000the role of kinetic microinstabilities in regulating collisionless plasma\u0000thermodynamics. This work provides insight into the open question of how\u0000specific plasma processes couple into the turbulent dynamics and ultimately\u0000lead to energy dissipation and particle energisation in collisionless plasmas.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866371","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

Not So Fast: A New Catalog of Meteor Persistent Trains 没那么快流星持久列车新目录

arXiv - PHYS - Space Physics Pub Date : 2024-07-25 DOI: arxiv-2407.18344

L. E. Cordonnier, K. S. Obenberger, J. M. Holmes, G. B. Taylor, D. Vida

{"title":"Not So Fast: A New Catalog of Meteor Persistent Trains","authors":"L. E. Cordonnier, K. S. Obenberger, J. M. Holmes, G. B. Taylor, D. Vida","doi":"arxiv-2407.18344","DOIUrl":"https://doi.org/arxiv-2407.18344","url":null,"abstract":"This paper presents the results of a nearly two year long campaign to detect\u0000and analyze meteor persistent trains (PTs) - self-emitting phenomena which can\u0000linger up to an hour after their parent meteor. The modern understanding of PTs\u0000has been primarily developed from the Leonid storms at the turn of the century;\u0000our goal was to assess the validity of these conclusions using a diverse sample\u0000of meteors with a wide range of velocities and magnitudes. To this end,\u0000year-round observations were recorded by the Widefield Persistent Train camera,\u00002nd edition (WiPT2) and were passed through a pipeline to filter out airplanes\u0000and flag potential meteors. These were classified by visual inspection based on\u0000the presence and duration of trains. Observed meteors were cross-referenced\u0000with the Global Meteor Network (GMN) database, which independently detects and\u0000calculates meteor parameters, enabling statistical analysis of PT-leaving\u0000meteors. There were 4726 meteors codetected by the GMN, with 636 of these\u0000leaving trains. Among these were a large population of slow, dim meteors that\u0000left PTs; these slower meteors had a greater train production rate relative to\u0000their faster counterparts. Unlike prior research, we did not find a clear\u0000magnitude cutoff or a strong association with fast meteor showers.\u0000Additionally, we note several interesting trends not previously reported, which\u0000include PT eligibility being primarily determined by a meteor's terminal height\u0000and an apparent dynamical origin dependence that likely reflects physical\u0000meteoroid properties.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866372","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 novel numerical method for mixed-frame multigroup radiation-hydrodynamics with GPU acceleration implemented in the QUOKKA code 在 QUOKKA 代码中使用 GPU 加速的新型混合框架多组辐射流体力学数值方法

arXiv - PHYS - Space Physics Pub Date : 2024-07-25 DOI: arxiv-2407.18304

Chong-Chong HeANU, Benjamin D. WibkingMSU, Mark R. KrumholzANU

{"title":"A novel numerical method for mixed-frame multigroup radiation-hydrodynamics with GPU acceleration implemented in the QUOKKA code","authors":"Chong-Chong HeANU, Benjamin D. WibkingMSU, Mark R. KrumholzANU","doi":"arxiv-2407.18304","DOIUrl":"https://doi.org/arxiv-2407.18304","url":null,"abstract":"Mixed-frame formulations of radiation-hydrodynamics (RHD), where the\u0000radiation quantities are computed in an inertial frame but matter quantities\u0000are in a comoving frame, are advantageous because they admit algorithms that\u0000conserve energy and momentum to machine precision and combine more naturally\u0000with adaptive mesh techniques, since unlike pure comoving-frame methods they do\u0000not face the problem that radiation quantities must change frame every time a\u0000cell is refined or coarsened. However, implementing multigroup RHD in a\u0000mixed-frame formulation presents challenges due to the complexity of handling\u0000frequency-dependent interactions and the Doppler shift of radiation boundaries.\u0000In this paper, we introduce a novel method for multigroup RHD that integrates a\u0000mixed-frame formulation with a piecewise powerlaw approximation for frequency\u0000dependence within groups. This approach ensures the exact conservation of total\u0000energy and momentum while effectively managing the Lorentz transformation of\u0000group boundaries and evaluation of group-averaged opacities. Our method takes\u0000advantage of the locality of matter-radiation coupling, allowing the source\u0000term for $N_g$ frequency groups to be handled with simple equations with a\u0000sparse Jacobian matrix of size $N_g + 1$, which can be inverted with $O(N_g)$\u0000complexity. This results in a computational complexity that scales linearly\u0000with $N_g$ and requires no more communication than a pure hydrodynamics update,\u0000making it highly efficient for massively parallel and GPU-based systems. We\u0000implement our method in the GPU-accelerated RHD code QUOKKA and demonstrate\u0000that it passes a wide range of numerical tests. We demonstrate that the\u0000piecewise powerlaw method shows significant advantages over traditional opacity\u0000averaging methods for handling rapidly variable opacities with modest frequency\u0000resolution.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866373","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

Reduction of the downward energy flux of non-thermal electrons in the solar flare corona due to co-spatial return current losses 共空间回流损失导致太阳耀斑日冕中的非热电子向下能量通量减少

arXiv - PHYS - Space Physics Pub Date : 2024-07-25 DOI: arxiv-2407.17955

Meriem Alaoui, Gordon D. Holman, Marc Swisdak

{"title":"Reduction of the downward energy flux of non-thermal electrons in the solar flare corona due to co-spatial return current losses","authors":"Meriem Alaoui, Gordon D. Holman, Marc Swisdak","doi":"arxiv-2407.17955","DOIUrl":"https://doi.org/arxiv-2407.17955","url":null,"abstract":"High energy electrons carry much of a solar flare's energy. Therefore,\u0000understanding changes in electron beam distributions during their propagation\u0000is crucial. A key focus of this paper is how the co-spatial return current\u0000reduces the energy flux carried by these accelerated electrons. We\u0000systematically compute this reduction for various beam and plasma parameters\u0000relevant to solar flares. Our 1D model accounts for collisions between beam and\u0000plasma electrons, return current electric-field deceleration, thermalization in\u0000a warm target approximation, and runaway electron contributions. The results\u0000focus on the classical (Spitzer) regime, offering a valuable benchmark for\u0000energy flux reduction and its extent. Return current losses are only negligible\u0000for the lowest nonthermal fluxes. We calculate the conditions for return\u0000current losses to become significant and estimate the extent of the\u0000modification to the beam's energy flux density. We also calculate two\u0000additional conditions which occur for higher injected fluxes: (1) where runaway\u0000electrons become significant, and (2) where current-driven instabilities might\u0000become significant, requiring a model that self-consistently accounts for them.\u0000Condition (2) is relaxed and the energy flux losses are reduced in the presence\u0000of runaway electrons. All results are dependent on beam and co-spatial plasma\u0000parameters. We also examine the importance of the reflection of beam electrons\u0000by the return-current electric field. We show that the interpretation of a\u0000number of flares needs to be reviewed to account for the effects of return\u0000currents.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141782660","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