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1. Advanced Methods for Analyzing in-Situ Observations of Magnetic Reconnection

Author

Hasegawa, H., Argall, M. R., Aunai, N., Bandyopadhyay, R., Bessho, N., Cohen, I. J., Denton, R. E., Dorelli, J. C., Egedal, J., Fuselier, S. A., Garnier, P., Génot, V., Graham, D. B., Hwang, K. J., Khotyaintsev, Y. V., Korovinskiy, D. B., Lavraud, B., Lenouvel, Q., Li, T. C., Liu, Y.-H., Michotte de Welle, B., Nakamura, T. K. M., Payne, D. S., Petrinec, S. M., Qi, Y., Rager, A. C., Reiff, P. H., Schroeder, J. M., Shuster, J. R., Sitnov, M. I., Stephens, G. K., Swisdak, M., Tian, A. M., Torbert, R. B., Trattner, K. J., and Zenitani, S.

Published
2024
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2. Advanced methods for analyzing in-situ observations of magnetic reconnection

Author

Hasegawa, H., Argall, M. R., Aunai, N., Bandyopadhyay, R., Bessho, N., Cohen, I. J., Denton, R. E., Dorelli, J. C., Egedal, J., Fuselier, S. A., Garnier, P., Genot, V., Graham, D. B., Hwang, K. J., Khotyaintsev, Y. V., Korovinskiy, D. B., Lavraud, B., Lenouvel, Q., Li, T. C., Liu, Y. -H., de Welle, B. Michotte, Nakamura, T. K. M., Payne, D. S., Petrinec, S. M., Qi, Y., Rager, A. C., Reiff, P. H., Schroeder, J. M., Shuster, J. R., Sitnov, M. I., Stephens, G. K., Swisdak, M., Tian, A. M., Torbert, R. B., Trattner, K. J., and Zenitani, S.

Subjects
Physics - Space Physics, Astrophysics - Earth and Planetary Astrophysics, Physics - Plasma Physics
Abstract

There is ample evidence for magnetic reconnection in the solar system, but it is a nontrivial task to visualize, to determine the proper approaches and frames to study, and in turn to elucidate the physical processes at work in reconnection regions from in-situ measurements of plasma particles and electromagnetic fields. Here an overview is given of a variety of single- and multi-spacecraft data analysis techniques that are key to revealing the context of in-situ observations of magnetic reconnection in space and for detecting and analyzing the diffusion regions where ions and/or electrons are demagnetized. We focus on recent advances in the era of the Magnetospheric Multiscale mission, which has made electron-scale, multi-point measurements of magnetic reconnection in and around Earth's magnetosphere., Comment: submitted to Space Science Reviews (116 pages, incl. 31 figures, 7 tables)

Published
2023

3. 2D reconstruction of magnetotail electron diffusion region measured by MMS

Author

Schroeder, J. M., Egedal, J., Cozzani, G., Khotyaintsev, Yu. V., Daughton, W., Denton, R. E., and Burch, J. L.

Subjects
Physics - Space Physics, Physics - Plasma Physics
Abstract

Models for collisionless magnetic reconnection in near-Earth space are distinctly characterized as 2D or 3D. In 2D kinetic models, the frozen-in law for the electron fluid is usually broken by laminar dynamics involving structures set by the electron orbit size, while in 3D models the width of the electron diffusion region is broadened by turbulent effects. We present an analysis of in situ spacecraft observations from the Earth's magnetotail of a fortuitous encounter with an active reconnection region, mapping the observations onto a 2D spatial domain. While the event likely was perturbed by low-frequency 3D dynamics, the structure of the electron diffusion region remains consistent with results from a 2D kinetic simulation. As such, the event represents a unique validation of 2D kinetic, and laminar reconnection models., Comment: Accepted for publication in Geophysical Research Letters. Copyright 2022 American Geophysical Union. Further reproduction or electronic distribution is not permitted. 11 pages. 5 figures

Published
2022

4. Discovery of pyrrolo[2,1-f][1,2,4]triazine-based inhibitors of adaptor protein 2-associated kinase 1 for the treatment of pain

Author

Dzierba, Carolyn D., Dasgupta, Bireshwar, Karageorge, George, Kostich, Walter, Hamman, Brian, Allen, Jason, Esposito, Kim M., Padmanabha, Ramesh, Grace, James, Lentz, Kimberley, Morrison, John, Morgan, Daniel, Easton, Amy, Bourin, Clotilde, Browning, Marc R., Rajamani, Ramkumar, Good, Andrew, Parker, Dawn D., Muckelbauer, Jodi K., Khan, Javed, Camac, Daniel, Ghosh, Kaushik, Halan, Vivek, Lippy, Jonathan S., Santone, Kenneth S., Denton, R. Rex, Westphal, Ryan, Bristow, Linda J., Conway, Charles M., Bronson, Joanne J., and Macor, John E.

Published
2023
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5. Multi-scale coupling during magnetopause reconnection: the interface between the electron and ion diffusion regions

Author

Genestreti, K. J., Liu, Y. -H., Phan, T. -D., Denton, R. E., Torbert, R. B., Burch, J. L., Webster, J. M., Wang, S., Trattner, K. J., Argall, M. R., Chen, L. -J., Fuselier, S. A., Ahmadi, N., Ergun, R. E., Giles, B. L., Russell, C. T., Strangeway, R. J., and Eriksson, S.

Subjects
Physics - Space Physics
Abstract

Magnetospheric Multiscale (MMS) encountered the primary low-latitude magnetopause reconnection site when the inter-spacecraft separation exceeded the upstream ion inertial length. Classical signatures of the ion diffusion region (IDR), including a sub-ion-Alfv\'enic de-magnetized ion exhaust, a super-ion-Alfv\'enic magnetized electron exhaust, and Hall electromagnetic fields, are identified. The opening angle between the magnetopause and magnetospheric separatrix is $30^\circ\pm5^\circ$. The exhaust preferentially expands sunward, displacing the magnetosheath. Intense pileup of reconnected magnetic flux occurs between the magnetosheath separatrix and the magnetopause in a narrow channel intermediate between the ion and electron scales. The strength of the pileup (normalized values of 0.3-0.5) is consistent with the large angle at which the magnetopause is inclined relative to the overall reconnection coordinates. MMS-4, which was two ion inertial lengths closer to the X-line than the other three spacecraft, observed intense electron-dominated currents and kinetic-to-electromagnetic-field energy conversion within the pileup. MMS-1, 2, and 3 did not observe the intense currents nor the particle-to-field energy conversion but did observe the pileup, indicating that the edge of the generation region was contained within the tetrahedron. Comparisons with particle-in-cell simulations reveal that the electron currents and large inclination angle of the magnetopause are interconnected features of the asymmetric Hall effect. Between the separatrix and the magnetopause, high-density inflowing magnetosheath electrons brake and turn into the outflow direction, imparting energy to the normal magnetic field and generating the pileup. The findings indicate that electron dynamics are likely an important influence on the magnetic field structure within the ion diffusion region., Comment: Submitted to the Journal of Geophysical Research: Space Physics

Published
2020
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6. Localized Oscillatory Dissipation in Magnetopause Reconnection

Author

Burch, J. L., Ergun, R. E., Cassak, P. A., Webster, J. M., Torbert, R. B., Giles, B. L., Dorelli, J. C., Rager, A. C., Hwang, K. -J., Phan, T. D., Genestreti, K. J., Allen, R. C., Chen, L. -J., Wang, S., Gershman, D., Contel, O. Le, Russell, C. T., Strangeway, R. J., Wilder, F. D., Graham, D. B., Hesse, M., Drake, J. F., Swisdak, M., Price, L. M., Shay, M. A., Lindqvist, P. -A., Pollock, C. J., Denton, R. E., and Newman, D. L.

Subjects
Physics - Space Physics, Astrophysics - Earth and Planetary Astrophysics, Physics - Plasma Physics
Abstract

Data from the NASA Magnetospheric Multiscale (MMS) mission are used to investigate asymmetric magnetic reconnection at the dayside boundary between the Earth's magnetosphere and the solar wind (the magnetopause). High-resolution measurements of plasmas, electric and magnetic fields, and waves are used to identify highly localized (~15 electron Debye lengths) standing wave structures with large electric-field amplitudes (up to 100 mV/m). These wave structures are associated with spatially oscillatory dissipation, which appears as alternatingly positive and negative values of J dot E (dissipation). For small guide magnetic fields the wave structures occur in the electron stagnation region at the magnetosphere edge of the EDR. For larger guide fields the structures also occur near the reconnection x-line. This difference is explained in terms of channels for the out-of-plane current (agyrotropic electrons at the stagnation point and guide-field-aligned electrons at the x-line).

Published
2017
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8. Ethnically-Based Theme House Residency and Expected Discrimination Predict Downstream Markers of Inflammation Among College Students

Author

Rheinschmidt-Same, M, John-Henderson, NA, and Mendoza-Denton, R

Subjects
racial/ethnic discrimination, inflammatory cytokines, immune system, higher education, Clinical Research, Behavioral and Social Science, Basic Behavioral and Social Science, Inflammatory and Immune System, Psychology
Abstract

We examined participation in an ethnically based residential program or “theme house” during the first year of college as a predictor of downstream immune system inflammation among undergraduates. Using a 4-year prospective design, we compared markers of inflammation among Latino/Latina students in a residential theme program with a matched sample of nonresidents. Students provided oral mucosal transudate samples for the assessment of circulating Interleukin 6 (IL-6), an inflammatory cytokine linked to health vulnerabilities. Findings suggest a protective benefit of theme house residency especially among students with anxious expectations of discrimination. Such expectations predicted higher levels of IL-6 after the first year of college among nonresidents only. In years 2–3, following exit from the theme house, the relationship between expected discrimination and IL-6 levels remained positive among nonresidents and was attenuated among residents, controlling for past IL-6 levels. Culturally based spaces may therefore offset the physiological burden of expected discrimination among undergraduates.

Published
2017

9. Reconnection Inside a Dipolarization Front of a Diverging Earthward Fast Flow

Author

Hosner, M., primary, Nakamura, R., additional, Schmid, D., additional, Nakamura, T. K. M., additional, Panov, E. V., additional, Volwerk, M., additional, Vörös, Z., additional, Roberts, O. W., additional, Blasl, K. A., additional, Settino, A., additional, Korovinskiy, D., additional, Marshall, A. T., additional, Denton, R. E., additional, Burch, J. L., additional, Giles, B. L., additional, Torbert, R. B., additional, Le Contel, O., additional, Escoubet, C. P., additional, Dandouras, I. S., additional, Carr, C., additional, and Fazakerley, A. N., additional

Published
2024
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10. Cytokine responses and math performance: The role of stereotype threat and anxiety reappraisals

Author

John-Henderson, NA, Rheinschmidt, ML, and Mendoza-Denton, R

Subjects
Stereotype threat, Reappraisal, Stress, Gender, Inflammation, Behavioral and Social Science, Social Psychology, Psychology, Cognitive Sciences
Abstract

This research independently manipulated two potential attenuators of stereotype threat - reappraisal of anxiety and test framing - to explore their independent and combined effects. Female participants took a difficult math exam that was described as gender-biased or gender-fair and were told that anxious arousal could positively impact performance or were given no information regarding arousal. Levels of the cytokine Interleukin-6 (IL-6), an immune marker of inflammation, were measured in oral mucosal transudate (OMT) both before and after the exam. Our findings indicate that directing reappraisal of physiological arousal attenuated increases in IL-6 across test framing conditions, and was especially effective under stereotype threat (i.e., gender-biased test condition). Reappraisal also mapped onto better test performance in the threat condition. Together, these findings provide insight into the unique and interactive effects of two situational interventions meant to reduce stereotype threat, indexed here by both physiological and performance-based correlates of threat.

Published
2015

12. Temporal, Spatial, and Velocity‐Space Variations of Electron Phase Space Density Measurements at the Magnetopause

Author

Shuster, J. R., primary, Gershman, D. J., additional, Giles, B. L., additional, Bessho, N., additional, Sharma, A. S., additional, Dorelli, J. C., additional, Uritsky, V., additional, Schwartz, S. J., additional, Cassak, P. A., additional, Denton, R. E., additional, Chen, L.‐J., additional, Gurram, H., additional, Ng, J., additional, Burch, J., additional, Webster, J., additional, Torbert, R., additional, Paterson, W. R., additional, Schiff, C., additional, Viñas, A. F., additional, Avanov, L. A., additional, Stawarz, J., additional, Li, T. C., additional, Liu, Y.‐H., additional, Argall, M. R., additional, Afshari, A., additional, Payne, D. S., additional, Farrugia, C. J., additional, Verniero, J., additional, Wilder, F., additional, Genestreti, K., additional, and da Silva, D. E., additional

Published
2023
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14. Temporal, Spatial, and Velocity-Space Variations of Electron Phase Space Density Measurements at the Magnetopause

Author

Shuster, J. R., Shuster, J. R., Gershman, D. J., Giles, B. L., Bessho, N., Sharma, A. S., Dorelli, J. C., Uritsky, V., Schwartz, S. J., Cassak, P. A., Denton, R. E., Chen, L.-J., Gurram, H., Ng, J., Burch, J., Webster, J., Torbert, R., Paterson, W. R., Schiff, C., Viñas, A. F., Avanov, L. A., Stawarz, J., Li, T. C., Liu, Y.-H., Argall, M. R., Afshari, A., Payne, D. S., Farrugia, C.J., Verniero, J., Wilder, F., Genestreti, K., da Silva, D. E., Shuster, J. R., Shuster, J. R., Gershman, D. J., Giles, B. L., Bessho, N., Sharma, A. S., Dorelli, J. C., Uritsky, V., Schwartz, S. J., Cassak, P. A., Denton, R. E., Chen, L.-J., Gurram, H., Ng, J., Burch, J., Webster, J., Torbert, R., Paterson, W. R., Schiff, C., Viñas, A. F., Avanov, L. A., Stawarz, J., Li, T. C., Liu, Y.-H., Argall, M. R., Afshari, A., Payne, D. S., Farrugia, C.J., Verniero, J., Wilder, F., Genestreti, K., and da Silva, D. E.

Abstract

Temporal, spatial, and velocity-space variations of electron phase space density are measured observationally and compared for the first time using the four magnetospheric multiscale (MMS) spacecraft at Earth's magnetopause. Equipped with these unprecedented spatiotemporal measurements offered by the MMS tetrahedron, we compute each term of the electron Vlasov equation that governs the evolution of collisionless plasmas found throughout the universe. We demonstrate how to use single spacecraft measurements to improve the resolution of the electron pressure gradient that supports nonideal parallel electric fields, and we develop a model to intuit the types of kinetic velocity-space signatures that are observed in the Vlasov equation terms. Furthermore, we discuss how the gradient in velocity-space sheds light on plasma energy conversion mechanisms and wave-particle interactions that occur in fundamental physical processes such as magnetic reconnection and turbulence.

Published
2023

16. Magnetoseismic study of the mass density and average ion mass in the inner magnetosphere using Van Allen Probes data

Author

Takahashi, K. and Denton, R.

Abstract

The frequencies of toroidal standing Alfven waves have been used to estimate the plasma mass density in the magnetosphere. This technique, known as normal mode magnetoseismology, is valuable because it is difficult to determine the mass density using particle experiments. With a comprehensive electric and magnetic field dataset available from Van Allen Probes for 2012- 2019, it is possible to apply the magnetoseismic technique to the spacecraft data to statistically determine the spatial distribution of the mass density in the inner magnetosphere. We can also derive the average ion mass using the electron density estimated using plasma wave spectra. We have determined the fundamental through third harmonic frequencies of toroidal waves in consecutive 15-min data segments covering the entire spacecraft mission period. The frequencies have been translated to the mass density by solving the toroidal wave equation of Singer et al. (1981) with the background magnetic field given by the T89 and TS05 models. The mass density estimates have been used to generate L-MLT maps of the mass density and average ion mass. An outstanding feature of the maps is strong MLT dependence. We discuss how this feature is related to the transport of heavy (O+) ions.&nbsp, The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023
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17. Modeling magnetospheric mass density and average ion mass using spacecraft observations

Author

Denton, R., Takahashi, K., Min, K., Hartley, D., and Nishimura, Y.

Abstract

By combining measurements of mass density from Alfven wave frequencies and electron density from plasma wave frequencies, we model both mass density and average ion mass in the magnetosphere between L = 2 and 10. Using a new model of the electron density at the midpoint of the plasmapause, we also separate the data into plasmasphere and plasmatrough portions. We then develop an empirical formulas for mass density and average ion mass within the plasmasphere and plasmatrough. The plasmasphere is composed almost totally of H+. The plasmatrough has a higher percentage of heavy ions, with average ion mass increasing with the solar EUV index F10.7, the geomagnetic activity index AE, solar wind dynamic pressure, and at pre-dawn local time and large L. We also demonstrate the danger of investigations of spatial dependence that do not take into account different conditions for different spatial regions sampled. In this study, we avoid this problem by using multivariate regression.

Published
2023

21. Mechanistic investigation of liver injury induced by BMS-932481, an experimental ɣ-secretase modulator.

Author

Zhuo, Xiaoliang, Howell, Brett A, Shen, Hong, Woodhead, Jeffrey L, Mosure, Kathy, Zhang, Yueping, Scialis, Renato J, Iyer, Ramaswamy, Sun, Yongnian, Boy, Kenneth M, Lentz, Kimberley A, Denton, R Rex, Soars, Matthew G, Johnson, Benjamin M, and Humphreys, W Griffith

Subjects
LIVER injuries, BILE salts, BILE acids, MULTIDRUG resistance, LIVER cells, PROTEIN binding
Abstract

BMS-932481 was designed to modulate ɣ-secretase activity to produce shorter and less amyloidogenic peptides, potentially averting liabilities associated with complete enzymatic inhibition. Although it demonstrated the intended pharmacology in the clinic, BMS-932481 unexpectedly caused drug-induced liver injury (DILI) in a multiple ascending dose study characterized by dose- and exposure-dependence, delayed onset manifestation, and a high incidence of hepatocellular damage. Retrospective studies investigating the disposition and probable mechanisms of toxicity of BMS-932481 are presented here. These included a mass balance study in bile-duct-cannulated rats and a metabolite profiling study in human hepatocytes, which together demonstrated oxidative metabolism followed by biliary elimination as the primary means of disposition. Additionally, minimal protein covalent binding in hepatocytes and lack of bioactivation products excluded reactive metabolite formation as a probable toxicological mechanism. However, BMS-932481 and 3 major oxidative metabolites were found to inhibit the bile salt export pump (BSEP) and multidrug resistance protein 4 (MRP4) in vitro. Considering human plasma concentrations, the IC50 values against these efflux transporters were clinically meaningful, particularly in the high dose cohort. Active uptake into human hepatocytes in vitro suggested the potential for hepatic levels of BMS-932481 to be elevated further above plasma concentrations, enhancing DILI risk. Conversely, measures of mitochondrial functional decline in hepatocytes treated with BMS-932481 were minimal or modest, suggesting limited contributions to DILI. Collectively, these findings suggested that repeat administration of BMS-932481 likely resulted in high hepatic concentrations of BMS-932481 and its metabolites, which disrupted bile acid transport via BSEP and MRP4, elevating serum biomarkers of liver injury. [ABSTRACT FROM AUTHOR]

Published
2023
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23. Magnetic Field Annihilation in a Magnetotail Electron Diffusion Region With Electron‐Scale Magnetic Island

Author

Hasegawa, H., primary, Denton, R. E., additional, Nakamura, T. K. M., additional, Genestreti, K. J., additional, Phan, T. D., additional, Nakamura, R., additional, Hwang, K.‐J., additional, Ahmadi, N., additional, Shi, Q. Q., additional, Hesse, M., additional, Burch, J. L., additional, Webster, J. M., additional, Torbert, R. B., additional, Giles, B. L., additional, Gershman, D. J., additional, Russell, C. T., additional, Strangeway, R. J., additional, Wei, H. Y., additional, Lindqvist, P.‐A., additional, Khotyaintsev, Y. V., additional, Ergun, R. E., additional, and Saito, Y., additional

Published
2022
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25. Magnetic Field Annihilation in a Magnetotail Electron Diffusion Region With Electron-Scale Magnetic Island

Author

Hasegawa, H., Denton, R. E., Nakamura, T. K. M., Genestreti, K. J., Phan, T. D., Nakamura, R., Hwang, K. -j., Ahmadi, N., Shi, Q. Q., Hesse, M., Burch, J. L., Webster, J. M., Torbert, R. B., Giles, B. L., Gershman, D. J., Russell, C. T., Strangeway, R. J., Wei, H. Y., Lindqvist, P. -A, Khotyaintsev, Yuri V., Ergun, R. E., Saito, Y., Hasegawa, H., Denton, R. E., Nakamura, T. K. M., Genestreti, K. J., Phan, T. D., Nakamura, R., Hwang, K. -j., Ahmadi, N., Shi, Q. Q., Hesse, M., Burch, J. L., Webster, J. M., Torbert, R. B., Giles, B. L., Gershman, D. J., Russell, C. T., Strangeway, R. J., Wei, H. Y., Lindqvist, P. -A, Khotyaintsev, Yuri V., Ergun, R. E., and Saito, Y.

Abstract

We present observations in Earth's magnetotail by the Magnetospheric Multiscale spacecraft that are consistent with magnetic field annihilation, rather than magnetic topology change, causing fast magnetic-to-electron energy conversion in an electron-scale current sheet. Multi-spacecraft analysis for the magnetic field reconstruction shows that an electron-scale magnetic island was embedded in the observed electron diffusion region (EDR), suggesting an elongated shape of the EDR. Evidence for the annihilation was revealed in the form of the island growing at a rate much lower than expected for the standard X-type geometry of the EDR, which indicates that magnetic flux injected into the EDR was not ejected from the X-point or accumulated in the island, but was dissipated in the EDR. This energy conversion process is in contrast to that in the standard EDR of a reconnecting current sheet where the energy of antiparallel magnetic fields is mostly converted to electron bulk-flow energy. Fully kinetic simulation also demonstrates that an elongated EDR is subject to the formation of electron-scale magnetic islands in which fast but transient annihilation can occur. Consistent with the observations and simulation, theoretical analysis shows that fast magnetic diffusion can occur in an elongated EDR in the presence of nongyrotropic electron effects. We suggest that the annihilation in elongated EDRs may contribute to the dissipation of magnetic energy in a turbulent collisionless plasma.

Published
2022
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26. The EDR inflow region of a reconnecting current sheet in the geomagnetic tail

Author

Burch, J. L., primary, Hesse, M., additional, Webster, J. M., additional, Genestreti, K. J., additional, Torbert, R. B., additional, Denton, R. E., additional, Ergun, R. E., additional, Giles, B. L., additional, Gershman, D. J., additional, Russell, C. T., additional, Wang, S., additional, Chen, L.-J., additional, Dokgo, K., additional, Hwang, K.-J., additional, and Pollock, C. J., additional

Published
2022
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30. Reconnection Guide Field and Quadrupolar Structure Observed by MMS on 16 October 2015 at 1307 UT

Author

Denton, R. E, Sonnerup, B. U. O, Hasagawa, H, Phan, T. D, Russell, C. T, Strangeway, R. J, Giles, B. L, and Torbert, R. B

Subjects
Space Sciences (General)
Abstract

We estimate the guide field near the X point, B(sub M0), for a magnetopause crossing by the Magnetospheric Multiscale (MMS) spacecraft at 1307 UT on 16 October 2015 that showed features of electron-scale reconnection. This component of the magnetic field is normal to the reconnection plane L-N containing the reconnection magnetic field, B(sub L), and the direction e(sub N) normal to the current sheet. The B(sub M) field component appears to approximately have quadrupolar structure close to the X point. Using several different methods to estimate values of the guide field near the X point, some of which use an assumed quadrupolar symmetry, we find values ranging between -3.1 nT and -1.2 nT, with a nominal value of about -2.5 nT. The rough consistency of these values is evidence that the quadrupolar structure exists.

Published
2016
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31. Motion of the MMS Spacecraft Relative to the Magnetic Reconnection Structure Observed on 16 October 2015 at 1307 UT

Author

Denton, R. E, Sonnerup, B. U. O, Hasegawa, H, Phan, T. D, Russell, C. T, Strangeway, R, Giles, B. L, Gershman, D, and Torbert, R. B

Subjects
Geophysics, Numerical Analysis
Abstract

We analyze a magnetopause crossing by the Magnetospheric Multiscale (MMS) spacecraft at 1307 UT on 16 October 2016 that showed features of electron-scale reconnection. For this event, we find orthonormal LMN coordinates from the magnetic field, with N and L varying respectively along the maximum gradient and maximum variance directions. We find the motion along N from the Spatio-Temporal Difference analysis and motion along L from measured particle velocities. We locate the position of the magnetic X point, finding that MMS-4 passed within about 1A km from the X point and that MMS-3 and MMS-2 passed within about 1.7 km and 2.4 km, respectively, from the position of maximum out of plane current.

Published
2016
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33. Anomalous Reconnection Layer at Earth's Dayside Magnetopause

Author

Paschmann, G., primary, Sonnerup, B. U. Ö., additional, Phan, T., additional, Fuselier, S. A., additional, Haaland, S., additional, Denton, R. E., additional, Burch, J. L., additional, Trattner, K. J., additional, Giles, B. L., additional, Gershman, D. J., additional, Cohen, I. J., additional, and Russell, C. T., additional

Published
2021
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34. Reconstruction of the Electron Diffusion Region of Magnetotail Reconnection Seen by the MMS Spacecraft on 11 July 2017

Author

Denton, R. E., Nakamura, R., Genestreti, K. J., Hwang, K.‐J., Phan, T. D., Torbert, R. B., Burch, J. L., Giles, B. L., Gershman, D. J., Russell, C. T., Strangeway, R. J., Lindqvist, P.‐A., Khotyaintsev, Y. V., Ergun, R. E., Hasegawa, Hiroshi, Nakamura, T. K. M., Kitamura, Naritoshi, and Saito, Yoshifumi

Subjects
Physics, Geophysics, Spacecraft, Space and Planetary Science, business.industry, Event (relativity), Physics::Space Physics, Magnetic reconnection, Electron, Diffusion (business), business, Computational physics
Abstract

著者人数: 18名, Accepted: 2018-11-03, 資料番号: SA1180295000

Published
2019

37. Kinetic Interaction of Cold and Hot Protons With an Oblique EMIC Wave Near the Dayside Reconnecting Magnetopause

Author

Toledo-Redondo, S., Lee, J. H., Vines, S. K., Turner, D. L., Allen, R. C., André, Mats, Boardsen, S. A., Burch, J. L., Denton, R. E., Fu, H. S., Fuselier, S. A., Gershman, D. J., Giles, B., Graham, Daniel B., Kitamura, N., Khotyaintsev, Yuri V., Lavraud, B., Le Contel, O., Li, W. Y., Moore, T. E., Navarro, E. A., Porti, J., Salinas, A., Vinas, A., Toledo-Redondo, S., Lee, J. H., Vines, S. K., Turner, D. L., Allen, R. C., André, Mats, Boardsen, S. A., Burch, J. L., Denton, R. E., Fu, H. S., Fuselier, S. A., Gershman, D. J., Giles, B., Graham, Daniel B., Kitamura, N., Khotyaintsev, Yuri V., Lavraud, B., Le Contel, O., Li, W. Y., Moore, T. E., Navarro, E. A., Porti, J., Salinas, A., and Vinas, A.

Abstract

We report observations of the ion dynamics inside an Alfven branch wave that propagates near the reconnecting dayside magnetopause. The measured frequency, wave normal angle and polarization are consistent with the predictions of a dispersion solver. The magnetospheric plasma contains hot protons (keV), cold protons (eV), plus some heavy ions. While the cold protons follow the magnetic field fluctuations and remain frozen-in, the hot protons are at the limit of magnetization. The cold protons exchange energy back and forth, adiabatically, with the wave fields. The cold proton velocity fluctuations contribute to balance the Hall term fluctuations in Ohm's law, and the wave E field has small ellipticity and right-handed polarization. The dispersion solver indicates that increasing the cold proton density facilitates propagation and amplification of these waves at oblique angles, as for the observed wave. Plain Language Summary The Earth's magnetosphere is a very dilute cloud of charged particles that are trapped in the Earth's magnetic field. This cloud is surrounded by the solar wind, another very dilute gas that flows supersonically throughout the solar system. These two plasmas can couple to each other via magnetic reconnection, a fundamental plasma process that occurs at the dayside region of the interface between the two plasmas. When reconnection occurs, large amounts of energy and particles enter the magnetosphere, driving the near Earth space dynamics and generating, for instance, aurorae. The magnetospheric plasma sources are the solar wind and the Earth's ionosphere. Multiple plasma populations can be found inside the Earth's magnetosphere, depending on the plasma origin and its time history, as well as the magnetospheric forcing of the solar wind. In this study, we show how the presence of multiple particle populations at the interface between the solar wind and the magnetosphere modifies the properties of the waves that propagate there. Waves are known to

Published
2021
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39. Kinetic Interaction of Cold and Hot Protons With an Oblique EMIC Wave Near the Dayside Reconnecting Magnetopause

Author

Toledo‐Redondo, S., primary, Lee, J. H., additional, Vines, S. K., additional, Turner, D. L., additional, Allen, R. C., additional, André, M., additional, Boardsen, S. A., additional, Burch, J. L., additional, Denton, R. E., additional, Fu, H. S., additional, Fuselier, S. A., additional, Gershman, D. J., additional, Giles, B., additional, Graham, D. B., additional, Kitamura, N., additional, Khotyaintsev, Yu. V., additional, Lavraud, B., additional, Le Contel, O., additional, Li, W. Y., additional, Moore, T. E., additional, Navarro, E. A., additional, Portí, J., additional, Salinas, A., additional, and Vinas, A., additional

Published
2021
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40. Determining EMIC Wave Vector Properties Through Multi‐Point Measurements: The Wave Curl Analysis

Author

Vines, S. K., primary, Anderson, B. J., additional, Allen, R. C., additional, Denton, R. E., additional, Engebretson, M. J., additional, Johnson, J. R., additional, Toledo‐Redondo, S., additional, Lee, J. H., additional, Turner, D. L., additional, Ergun, R. E., additional, Strangeway, R. J., additional, Russell, C. T., additional, Wei, H., additional, Torbert, R. B., additional, Fuselier, S. A., additional, Giles, B. L., additional, and Burch, J. L., additional

Published
2021
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41. Polynomial Reconstruction of the Reconnection Magnetic Field Observed by Multiple Spacecraft

Author

Denton, R. E., Torbert, R. B., Dors, I., Genestreti, K. J., Argall, M., Gershman, D. J., Le, Contel O., Burch, J. L., Russell, C. T., Strangeway, R. J., Giles, B. L., Fischer, D., Hasegawa, Hiroshi, University of New Hampshire (UNH), Laboratoire des sciences et matériaux pour l'électronique et d'automatique (LASMEA), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Centre National de la Recherche Scientifique (CNRS), EOS Space Science Center [Durham], Laboratoire de Physique des Plasmas (LPP), Université Paris-Saclay-Sorbonne Université-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École polytechnique (X)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU), Southwest Research Institute [San Antonio] (SwRI), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Institute of Geophysics and Planetary Physics [Los Angeles] (IGPP), Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Polynomial, 010504 meteorology & atmospheric sciences, Spacecraft, business.industry, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Magnetic reconnection, Plasmoid, 01 natural sciences, Magnetic field, Computational physics, Geophysics, Space and Planetary Science, 0103 physical sciences, business, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

著者人数: 13名, Accepted: 2019-12-11, 資料番号: SA1190210000

Published
2020

44. Multiscale Coupling During Magnetopause Reconnection: Interface Between the Electron and Ion Diffusion Regions

Author

Genestreti, K. J., primary, Liu, Y.‐H., additional, Phan, T.‐D., additional, Denton, R. E., additional, Torbert, R. B., additional, Burch, J. L., additional, Webster, J. M., additional, Wang, S., additional, Trattner, K. J., additional, Argall, M. R., additional, Chen, L.‐J., additional, Fuselier, S. A., additional, Ahmadi, N., additional, Ergun, R. E., additional, Giles, B. L., additional, Russell, C. T., additional, Strangeway, R. J., additional, and Eriksson, S., additional

Published
2020
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46. Electron Inflow Velocities and Reconnection Rates at Earth's Magnetopause and Magnetosheath

Author

Burch, J. L., primary, Webster, J. M., additional, Hesse, M., additional, Genestreti, K. J., additional, Denton, R. E., additional, Phan, T. D., additional, Hasegawa, H., additional, Cassak, P. A., additional, Torbert, R. B., additional, Giles, B. L., additional, Gershman, D. J., additional, Ergun, R. E., additional, Russell, C. T., additional, Strangeway, R. J., additional, Le Contel, O., additional, Pritchard, K. R., additional, Marshall, A. T., additional, Hwang, K.‐J., additional, Dokgo, K., additional, Fuselier, S. A., additional, Chen, L.‐J., additional, Wang, S., additional, Swisdak, M., additional, Drake, J. F., additional, Argall, M. R., additional, Trattner, K. J., additional, Yamada, M., additional, and Paschmann, G., additional

Published
2020
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49. Reconstruction of the electron diffusion region observed by the Magnetospheric Multiscale spacecraft: First results

Author

Sonnerup, B. U. O., Denton, R. E., Phan, T. -D., Giles, B. L., Gershman, D. J., Dorelli, J. C., Burch, J. L., Torbert, R. B., Russell, C. T., Strangeway, R. J., Lindqvist, P. -A., Khotyaintsev, Y. V., Ergun, R. E., Cassak, P. A., Hasegawa, Hiroshi, Nakamura, T. K. M., Kitamura, Naritoshi, and Saito, Yoshifumi

Subjects
Physics, 010504 meteorology & atmospheric sciences, Magnetic reconnection, Electron, Geophysics, 01 natural sciences, Computational physics, Magnetic field, Current sheet, Electric field, Physics::Space Physics, 0103 physical sciences, General Earth and Planetary Sciences, Magnetopause, Magnetohydrodynamics, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Dimensionless quantity
Abstract

著者人数: 18名, Accepted: 2017-05-09, 資料番号: SA1170022000

Published
2017

50. Measuring the magnetic structure velocity for the 11 July 2017 magnetotail reconnection event

Author

Denton, R. E., Hasegawa, H., Torbert, R. B., Manuzzo, Roberto, Sonnerup, B. U. Ö., Genestreti, K. J., Dors, I., Belmont, Gérard, Rezeau, Laurence, Califano, F., Department of Physics and Astronomy [Hanover], Dartmouth College [Hanover], University of New Hampshire (UNH), Laboratoire de Physique des Plasmas (LPP), Université Paris-Saclay-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École polytechnique (X)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Thayer School of Engineering, Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), University of Pisa - Università di Pisa, and PIBERNE, Rodrigue

Subjects
[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], [PHYS.PHYS.PHYS-PLASM-PH] Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], Physics::Space Physics, [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; Velocities in magnetic reconnection events, such as those of particles, are best understood in the frame of reference of the magnetic structure that is ultimately responsible for the reconnection process. We discuss four different methods for evaluating the velocity of the magnetic structure, and use those methods to find the magnetic structure velocity for the 11 July 2017 magnetotail reconnection event studied by Torbert et al. (Science, 2018). The four methods are timing analysis, the SpatioTemporal Difference (STD) method of Shi et al. (JGR, 2006), Electron Magnetohydrodynamic (EMHD) reconstruction (Sonnerup et al., JGR, 2016), and polynomial reconstruction of the magnetic field in the vicinity of the spacecraft using the magnetic field and particle current density as input to the model. The relative merits of the different techniques will be discussed, and the different results compared.

Published
2019

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