1
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Phan TD, Verniero JL, Larson D, Lavraud B, Drake JF, Øieroset M, Eastwood JP, Bale SD, Livi R, Halekas JS, Whittlesey PL, Rahmati A, Stansby D, Pulupa M, MacDowall RJ, Szabo PA, Koval A, Desai M, Fuselier SA, Velli M, Hesse M, Pyakurel PS, Maheshwari K, Kasper JC, Stevens JM, Case AW, Raouafi NE. Parker Solar Probe Observations of Solar Wind Energetic Proton Beams Produced by Magnetic Reconnection in the Near-Sun Heliospheric Current Sheet. Geophys Res Lett 2022; 49:e2021GL096986. [PMID: 35864893 PMCID: PMC9286436 DOI: 10.1029/2021gl096986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 03/21/2022] [Accepted: 03/30/2022] [Indexed: 06/09/2023]
Abstract
We report observations of reconnection exhausts in the Heliospheric Current Sheet (HCS) during Parker Solar Probe Encounters 08 and 07, at 16 R s and 20 R s , respectively. Heliospheric current sheet (HCS) reconnection accelerated protons to almost twice the solar wind speed and increased the proton core energy by a factor of ∼3, due to the Alfvén speed being comparable to the solar wind flow speed at these near-Sun distances. Furthermore, protons were energized to super-thermal energies. During E08, energized protons were found to have leaked out of the exhaust along separatrix field lines, appearing as field-aligned energetic proton beams in a broad region outside the HCS. Concurrent dropouts of strahl electrons, indicating disconnection from the Sun, provide further evidence for the HCS being the source of the beams. Around the HCS in E07, there were also proton beams but without electron strahl dropouts, indicating that their origin was not the local HCS reconnection exhaust.
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Affiliation(s)
- T. D. Phan
- SSLUniversity of CaliforniaBerkeleyCAUSA
| | | | - D. Larson
- SSLUniversity of CaliforniaBerkeleyCAUSA
| | - B. Lavraud
- Laboratoire d'Astrophysique de BordeauxUniversity BordeauxPessacFrance
- IRAPCNRSCNESUniversité de ToulouseToulouseFrance
| | | | | | | | - S. D. Bale
- SSLUniversity of CaliforniaBerkeleyCAUSA
- Physics DepartmentUniversity of CaliforniaBerkeleyCAUSA
| | - R. Livi
- SSLUniversity of CaliforniaBerkeleyCAUSA
| | | | | | - A. Rahmati
- SSLUniversity of CaliforniaBerkeleyCAUSA
| | - D. Stansby
- Mullard Space Science LaboratoryUniversity College LondonDorkingUK
| | - M. Pulupa
- SSLUniversity of CaliforniaBerkeleyCAUSA
| | | | - P. A. Szabo
- NASA Goddard Space Flight CenterGreenbeltMDUSA
| | - A. Koval
- NASA Goddard Space Flight CenterGreenbeltMDUSA
- University of MarylandBaltimore CountyBaltimoreMDUSA
| | - M. Desai
- Southwest Research InstituteSan AntonioTXUSA
| | | | - M. Velli
- University of CaliforniaLos AngelesCAUSA
| | - M. Hesse
- NASA Ames Research CenterMoffett FieldCAUSA
| | | | | | - J. C. Kasper
- Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
| | | | - A. W. Case
- Smithsonian Astrophysical ObservatoryCambridgeMAUSA
| | - N. E. Raouafi
- Johns Hopkins University Applied Physics LaboratoryLaurelMDUSA
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2
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Garnier P, Jacquey C, Gendre X, Génot V, Mazelle C, Fang X, Gruesbeck JR, Sánchez‐Cano B, Halekas JS. The Drivers of the Martian Bow Shock Location: A Statistical Analysis of Mars Atmosphere and Volatile EvolutioN and Mars Express Observations. J Geophys Res Space Phys 2022; 127:e2021JA030147. [PMID: 35865127 PMCID: PMC9287072 DOI: 10.1029/2021ja030147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 04/27/2022] [Accepted: 05/07/2022] [Indexed: 06/15/2023]
Abstract
The Martian interaction with the solar wind leads to the formation of a bow shock upstream of the planet. The shock dynamics appear complex, due to the combined influence of external and internal drivers. The extreme ultraviolet fluxes and magnetosonic Mach number are known major drivers of the shock location, while the influence of other possible drivers is less constrained or unknown such as crustal magnetic fields, solar wind dynamic pressure, or the Interplanetary Magnetic Field (IMF) intensity, and orientation. In this study, we compare the influence of the main drivers of the Martian shock location, based on several methods and published datasets from Mars Express (MEX) and Mars Atmosphere Volatile EvolutioN (MAVEN) missions. We include here the influence of the crustal fields, extreme ultraviolet fluxes, solar wind dynamic pressure, as well as (for MAVEN, thanks to magnetic field measurements) magnetosonic Mach number and Interplanetary Magnetic Field parameters (intensity and orientation angles). The bias due to the cross-correlations among the possible drivers is investigated with a partial correlations analysis. Several model selection methods (Akaike Information Criterion and Least Absolute Shrinkage Selection Operator regression) are also used to rank the relative importance of the physical parameters. We conclude that the major drivers of the shock location are extreme ultraviolet fluxes and magnetosonic Mach number, while crustal fields and solar wind dynamic pressure are secondary drivers at a similar level. The IMF orientation also plays a significant role, with larger distances for perpendicular shocks rather than parallel shocks.
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Affiliation(s)
- P. Garnier
- IRAPUniversité de ToulouseCNESCNRSUPSToulouseFrance
| | - C. Jacquey
- IRAPUniversité de ToulouseCNESCNRSUPSToulouseFrance
| | - X. Gendre
- ISAE‐SUPAEROUniversité de ToulouseToulouseFrance
| | - V. Génot
- IRAPUniversité de ToulouseCNESCNRSUPSToulouseFrance
| | - C. Mazelle
- IRAPUniversité de ToulouseCNESCNRSUPSToulouseFrance
| | - X. Fang
- Laboratory for Atmospheric and Space Physics University of ColoradoBoulderCOUSA
| | - J. R. Gruesbeck
- Department of AstronomyUniversity of MarylandCollege ParkMDUSA
- NASA Goddard Space Flight CenterGreenbeltMDUSA
| | - B. Sánchez‐Cano
- School of Physics and AstronomyUniversity of LeicesterLeicesterUK
| | - J. S. Halekas
- Department of Physics and AstronomyUniversity of IowaIowaIAUSA
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3
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Kasper JC, Klein KG, Lichko E, Huang J, Chen CHK, Badman ST, Bonnell J, Whittlesey PL, Livi R, Larson D, Pulupa M, Rahmati A, Stansby D, Korreck KE, Stevens M, Case AW, Bale SD, Maksimovic M, Moncuquet M, Goetz K, Halekas JS, Malaspina D, Raouafi NE, Szabo A, MacDowall R, Velli M, Dudok de Wit T, Zank GP. Parker Solar Probe Enters the Magnetically Dominated Solar Corona. Phys Rev Lett 2021; 127:255101. [PMID: 35029449 DOI: 10.1103/physrevlett.127.255101] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/09/2021] [Accepted: 11/15/2021] [Indexed: 06/14/2023]
Abstract
The high temperatures and strong magnetic fields of the solar corona form streams of solar wind that expand through the Solar System into interstellar space. At 09:33 UT on 28 April 2021 Parker Solar Probe entered the magnetized atmosphere of the Sun 13 million km above the photosphere, crossing below the Alfvén critical surface for five hours into plasma in casual contact with the Sun with an Alfvén Mach number of 0.79 and magnetic pressure dominating both ion and electron pressure. The spectrum of turbulence below the Alfvén critical surface is reported. Magnetic mapping suggests the region was a steady flow emerging on rapidly expanding coronal magnetic field lines lying above a pseudostreamer. The sub-Alfvénic nature of the flow may be due to suppressed magnetic reconnection at the base of the pseudostreamer, as evidenced by unusually low densities in this region and the magnetic mapping.
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Affiliation(s)
- J C Kasper
- BWX Technologies, Inc., Washington, DC 20001, USA and Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - K G Klein
- Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona 85719, USA
| | - E Lichko
- Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona 85719, USA
| | - Jia Huang
- Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - C H K Chen
- Department of Physics and Astronomy, Queen Mary University of London, London E1 4NS, United Kingdom
| | - S T Badman
- Space Sciences Laboratory at University of California, Berkeley, California, USA
| | - J Bonnell
- Space Sciences Laboratory at University of California, Berkeley, California, USA
| | - P L Whittlesey
- Space Sciences Laboratory at University of California, Berkeley, California, USA
| | - R Livi
- Space Sciences Laboratory at University of California, Berkeley, California, USA
| | - D Larson
- Space Sciences Laboratory at University of California, Berkeley, California, USA
| | - M Pulupa
- Space Sciences Laboratory at University of California, Berkeley, California, USA
| | - A Rahmati
- Space Sciences Laboratory at University of California, Berkeley, California, USA
| | - D Stansby
- Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Surrey RH5 6NT, United Kingdom
| | - K E Korreck
- Smithsonian Astrophysical Observatory, Cambridge, Massachusetts 02138, USA
| | - M Stevens
- Smithsonian Astrophysical Observatory, Cambridge, Massachusetts 02138, USA
| | - A W Case
- Smithsonian Astrophysical Observatory, Cambridge, Massachusetts 02138, USA
| | - S D Bale
- Physics Department, University of California, Berkeley, California 94720-7300, USA and Space Sciences Laboratory at University of California, Berkeley, California 94720-7300, USA
| | - M Maksimovic
- LESIA, Observatoire de Paris, Universite PSL, CNRS, Sorbonne Universite, Universite de Paris, 5 place Jules Janssen, 92195 Meudon, France
| | - M Moncuquet
- LESIA, Observatoire de Paris, Universite PSL, CNRS, Sorbonne Universite, Universite de Paris, 5 place Jules Janssen, 92195 Meudon, France
| | - K Goetz
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - J S Halekas
- Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA
| | - D Malaspina
- Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder, Colorado 80303, USA
| | - Nour E Raouafi
- The Johns Hopkins Applied Physics Laboratory, Laurel, Maryland 20723, USA
| | - A Szabo
- Heliospheric Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771, USA
| | - R MacDowall
- Heliospheric Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771, USA
| | - Marco Velli
- Earth Planetary and Space Sciences, UCLA, California 90095, USA
| | | | - G P Zank
- Department of Space Science and Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, Alabama 35805, USA
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4
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Ruhunusiri S, Howes GG, Halekas JS. Plasma Turbulence at Comet 67P/Churyumov-Gerasimenko: Rosetta Observations. J Geophys Res Space Phys 2020; 125:e2020JA028100. [PMID: 34381663 PMCID: PMC8350962 DOI: 10.1029/2020ja028100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 08/18/2020] [Indexed: 06/13/2023]
Abstract
We perform a power spectral analysis of magnetic field fluctuations measured by the Rosetta spacecraft's magnetometer at comet 67P/Churyumov-Gerasimenko. We interpret the power spectral signatures in terms of plasma turbulent processes and discover that different turbulent processes are prominent during different active phases of the comet. During the weakly active phase of the comet, dominant injection is prominent at low frequencies near 10-2 Hz, while partial energy cascade or dispersion is prominent at high frequencies near 10-1 Hz. During the intermediately active phase, uniform injection is prominent at low frequencies, while partial energy cascade or dispersion is prominent at high frequencies. During the strongly active phase of the comet, we find that partial energy cascade or dissipation is dominant at low frequencies, while partial energy cascade, dissipation, or dispersion is dominant at high frequencies. We infer that the temporal variations of the turbulent processes occur due to the evolution of the plasma environment of the comet as it orbits the Sun.
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Affiliation(s)
- S. Ruhunusiri
- Department of Physics and Astronomy, The University of Iowa, Iowa City, IA, USA
| | - G. G. Howes
- Department of Physics and Astronomy, The University of Iowa, Iowa City, IA, USA
| | - J. S. Halekas
- Department of Physics and Astronomy, The University of Iowa, Iowa City, IA, USA
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5
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Howard SK, Halekas JS, Farrell WM, McFadden JP, Glassmeier KH. Solar Wind and Interplanetary Magnetic Field Influence on Ultralow Frequency Waves and Reflected Ions Near the Moon. J Geophys Res Space Phys 2020; 125:e2019JA027209. [PMID: 33505828 PMCID: PMC7837449 DOI: 10.1029/2019ja027209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 01/17/2020] [Indexed: 06/12/2023]
Abstract
With no global magnetic field or atmosphere, the Moon was traditionally seen as a perfect absorber of the incoming solar wind. Recently, it has become apparent that magnetic fields with sources in the lunar crust act to reflect a significant percentage of incoming solar wind particles, which can then interact with the surrounding plasma environment and drive plasma waves. Using data collected by the Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) spacecraft, we look for simultaneous observations of reflected ions and 0.01 Hz waves to study the characteristics and conditions under which wave-particle resonant interactions occur. Analyzing the solar wind and interplanetary magnetic field during these observations reveals particular solar wind and interplanetary magnetic field conditions that favor the generation of these waves. We use an ion tracing program to produce reflected ion distributions for various ambient conditions. These distributions show that the conditions that lead to more ions crossing the equatorial region where ARTEMIS orbits are also those favored for wave observations. Low-frequency waves, such as those generated by cyclotron resonance with ions, can be heavily Doppler shifted, making it difficult to determine their intrinsic properties. Reflected ion distributions for the same ambient conditions as the observed waves suggest that most of the waves are intrinsically right-hand polarized.
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Affiliation(s)
- S. K. Howard
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA, USA
| | - J. S. Halekas
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA, USA
| | - W. M. Farrell
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - J. P. McFadden
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - K.-H. Glassmeier
- Institut für Geophysik und Extraterrestrische Physik, Technische Universität Braunschweig, Braunschweig, Germany
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6
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Kasper JC, Bale SD, Belcher JW, Berthomier M, Case AW, Chandran BDG, Curtis DW, Gallagher D, Gary SP, Golub L, Halekas JS, Ho GC, Horbury TS, Hu Q, Huang J, Klein KG, Korreck KE, Larson DE, Livi R, Maruca B, Lavraud B, Louarn P, Maksimovic M, Martinovic M, McGinnis D, Pogorelov NV, Richardson JD, Skoug RM, Steinberg JT, Stevens ML, Szabo A, Velli M, Whittlesey PL, Wright KH, Zank GP, MacDowall RJ, McComas DJ, McNutt RL, Pulupa M, Raouafi NE, Schwadron NA. Alfvénic velocity spikes and rotational flows in the near-Sun solar wind. Nature 2019; 576:228-231. [PMID: 31802006 DOI: 10.1038/s41586-019-1813-z] [Citation(s) in RCA: 216] [Impact Index Per Article: 43.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/17/2019] [Indexed: 11/09/2022]
Abstract
The prediction of a supersonic solar wind1 was first confirmed by spacecraft near Earth2,3 and later by spacecraft at heliocentric distances as small as 62 solar radii4. These missions showed that plasma accelerates as it emerges from the corona, aided by unidentified processes that transport energy outwards from the Sun before depositing it in the wind. Alfvénic fluctuations are a promising candidate for such a process because they are seen in the corona and solar wind and contain considerable energy5-7. Magnetic tension forces the corona to co-rotate with the Sun, but any residual rotation far from the Sun reported until now has been much smaller than the amplitude of waves and deflections from interacting wind streams8. Here we report observations of solar-wind plasma at heliocentric distances of about 35 solar radii9-11, well within the distance at which stream interactions become important. We find that Alfvén waves organize into structured velocity spikes with duration of up to minutes, which are associated with propagating S-like bends in the magnetic-field lines. We detect an increasing rotational component to the flow velocity of the solar wind around the Sun, peaking at 35 to 50 kilometres per second-considerably above the amplitude of the waves. These flows exceed classical velocity predictions of a few kilometres per second, challenging models of circulation in the corona and calling into question our understanding of how stars lose angular momentum and spin down as they age12-14.
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Affiliation(s)
- J C Kasper
- Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, USA. .,Smithsonian Astrophysical Observatory, Cambridge, MA, USA.
| | - S D Bale
- Physics Department, University of California, Berkeley, CA, USA.,Space Sciences Laboratory, University of California, Berkeley, CA, USA.,The Blackett Laboratory, Imperial College London, London, UK
| | - J W Belcher
- Kavli Center for Astrophysics and Space Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - M Berthomier
- Laboratoire de Physique des Plasmas, CNRS, Sorbonne Université, Ecole Polytechnique, Observatoire de Paris, Université Paris-Saclay, Paris, France
| | - A W Case
- Smithsonian Astrophysical Observatory, Cambridge, MA, USA
| | - B D G Chandran
- Department of Physics and Astronomy, University of New Hampshire, Durham, NH, USA.,Space Science Center, University of New Hampshire, Durham, NH, USA
| | - D W Curtis
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - D Gallagher
- Heliophysics and Planetary Science Branch ST13, Marshall Space Flight Center, Huntsville, AL, USA
| | - S P Gary
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | - L Golub
- Smithsonian Astrophysical Observatory, Cambridge, MA, USA
| | - J S Halekas
- Department of Physics and Astronomy, University of Iowa, IA, USA
| | - G C Ho
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - T S Horbury
- The Blackett Laboratory, Imperial College London, London, UK
| | - Q Hu
- Department of Space Science and Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL, USA
| | - J Huang
- Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, USA
| | - K G Klein
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA.,Department of Planetary Sciences, University of Arizona, Tucson, AZ, USA
| | - K E Korreck
- Smithsonian Astrophysical Observatory, Cambridge, MA, USA
| | - D E Larson
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - R Livi
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - B Maruca
- Department of Physics and Astronomy, University of Delaware, Newark, DE, USA.,Bartol Research Institute, University of Delaware, Newark, DE, USA
| | - B Lavraud
- Institut de Recherche en Astrophysique et Planétologie, CNRS, UPS, CNES, Université de Toulouse, Toulouse, France
| | - P Louarn
- Institut de Recherche en Astrophysique et Planétologie, CNRS, UPS, CNES, Université de Toulouse, Toulouse, France
| | - M Maksimovic
- LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris, Meudon, France
| | - M Martinovic
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - D McGinnis
- Department of Physics and Astronomy, University of Iowa, IA, USA
| | - N V Pogorelov
- Department of Space Science and Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL, USA
| | - J D Richardson
- Kavli Center for Astrophysics and Space Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - R M Skoug
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | | | - M L Stevens
- Smithsonian Astrophysical Observatory, Cambridge, MA, USA
| | - A Szabo
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - M Velli
- Department of Earth, Planetary and Space Sciences, University of California, Los Angeles, CA, USA
| | - P L Whittlesey
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - K H Wright
- Universities Space Research Association, Science and Technology Institute, Huntsville, AL, USA
| | - G P Zank
- Department of Space Science and Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL, USA
| | - R J MacDowall
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - D J McComas
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ, USA
| | - R L McNutt
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - M Pulupa
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - N E Raouafi
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - N A Schwadron
- Department of Physics and Astronomy, University of New Hampshire, Durham, NH, USA.,Space Science Center, University of New Hampshire, Durham, NH, USA
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7
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Angelopoulos V, Cruce P, Drozdov A, Grimes EW, Hatzigeorgiu N, King DA, Larson D, Lewis JW, McTiernan JM, Roberts DA, Russell CL, Hori T, Kasahara Y, Kumamoto A, Matsuoka A, Miyashita Y, Miyoshi Y, Shinohara I, Teramoto M, Faden JB, Halford AJ, McCarthy M, Millan RM, Sample JG, Smith DM, Woodger LA, Masson A, Narock AA, Asamura K, Chang TF, Chiang CY, Kazama Y, Keika K, Matsuda S, Segawa T, Seki K, Shoji M, Tam SWY, Umemura N, Wang BJ, Wang SY, Redmon R, Rodriguez JV, Singer HJ, Vandegriff J, Abe S, Nose M, Shinbori A, Tanaka YM, UeNo S, Andersson L, Dunn P, Fowler C, Halekas JS, Hara T, Harada Y, Lee CO, Lillis R, Mitchell DL, Argall MR, Bromund K, Burch JL, Cohen IJ, Galloy M, Giles B, Jaynes AN, Le Contel O, Oka M, Phan TD, Walsh BM, Westlake J, Wilder FD, Bale SD, Livi R, Pulupa M, Whittlesey P, DeWolfe A, Harter B, Lucas E, Auster U, Bonnell JW, Cully CM, Donovan E, Ergun RE, Frey HU, Jackel B, Keiling A, Korth H, McFadden JP, Nishimura Y, Plaschke F, Robert P, Turner DL, Weygand JM, Candey RM, Johnson RC, Kovalick T, Liu MH, McGuire RE, Breneman A, Kersten K, Schroeder P. The Space Physics Environment Data Analysis System (SPEDAS). Space Sci Rev 2019; 215:9. [PMID: 30880847 PMCID: PMC6380193 DOI: 10.1007/s11214-018-0576-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 12/29/2018] [Indexed: 05/31/2023]
Abstract
With the advent of the Heliophysics/Geospace System Observatory (H/GSO), a complement of multi-spacecraft missions and ground-based observatories to study the space environment, data retrieval, analysis, and visualization of space physics data can be daunting. The Space Physics Environment Data Analysis System (SPEDAS), a grass-roots software development platform (www.spedas.org), is now officially supported by NASA Heliophysics as part of its data environment infrastructure. It serves more than a dozen space missions and ground observatories and can integrate the full complement of past and upcoming space physics missions with minimal resources, following clear, simple, and well-proven guidelines. Free, modular and configurable to the needs of individual missions, it works in both command-line (ideal for experienced users) and Graphical User Interface (GUI) mode (reducing the learning curve for first-time users). Both options have "crib-sheets," user-command sequences in ASCII format that can facilitate record-and-repeat actions, especially for complex operations and plotting. Crib-sheets enhance scientific interactions, as users can move rapidly and accurately from exchanges of technical information on data processing to efficient discussions regarding data interpretation and science. SPEDAS can readily query and ingest all International Solar Terrestrial Physics (ISTP)-compatible products from the Space Physics Data Facility (SPDF), enabling access to a vast collection of historic and current mission data. The planned incorporation of Heliophysics Application Programmer's Interface (HAPI) standards will facilitate data ingestion from distributed datasets that adhere to these standards. Although SPEDAS is currently Interactive Data Language (IDL)-based (and interfaces to Java-based tools such as Autoplot), efforts are under-way to expand it further to work with python (first as an interface tool and potentially even receiving an under-the-hood replacement). We review the SPEDAS development history, goals, and current implementation. We explain its "modes of use" with examples geared for users and outline its technical implementation and requirements with software developers in mind. We also describe SPEDAS personnel and software management, interfaces with other organizations, resources and support structure available to the community, and future development plans. ELECTRONIC SUPPLEMENTARY MATERIAL The online version of this article (10.1007/s11214-018-0576-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- V. Angelopoulos
- Department of Earth, Planetary and Space Sciences, and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, USA
| | - P. Cruce
- Department of Earth, Planetary and Space Sciences, and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, USA
| | - A. Drozdov
- Department of Earth, Planetary and Space Sciences, and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, USA
| | - E. W. Grimes
- Department of Earth, Planetary and Space Sciences, and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, USA
| | - N. Hatzigeorgiu
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - D. A. King
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - D. Larson
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - J. W. Lewis
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - J. M. McTiernan
- Space Sciences Laboratory, University of California, Berkeley, USA
| | | | - C. L. Russell
- Department of Earth, Planetary and Space Sciences, and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, USA
| | - T. Hori
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan
| | | | - A. Kumamoto
- Tohoku University, 6-3, Aoba, Aramaki, Aoba Sendai, 980-8578 Japan
| | - A. Matsuoka
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Japan
| | - Y. Miyashita
- Korea Astronomy and Space Science Institute, Daejeon, South Korea
| | - Y. Miyoshi
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan
| | - I. Shinohara
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Japan
| | - M. Teramoto
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan
| | | | - A. J. Halford
- Space Sciences Department, The Aerospace Corporation, Chantilly, VA USA
| | - M. McCarthy
- Department of Earth and Space Sciences, University of Washington, Seattle, WA USA
| | - R. M. Millan
- Department of Physics and Astronomy, Dartmouth College, Hanover, NH USA
| | - J. G. Sample
- Department of Physics, Montana State University, Bozeman, MT USA
| | - D. M. Smith
- Santa Cruz Institute of Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 USA
| | - L. A. Woodger
- Department of Physics and Astronomy, Dartmouth College, Hanover, NH USA
| | - A. Masson
- European Space Agency, ESAC, SCI-OPD, Madrid, Spain
| | - A. A. Narock
- ADNET Systems Inc., NASA Goddard Space Flight Center, Greenbelt, MD USA
| | - K. Asamura
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Japan
| | - T. F. Chang
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan
| | - C.-Y. Chiang
- Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Y. Kazama
- Academia Sinica Institute of Astronomy and Astrophysics, Taipei, Taiwan
| | - K. Keika
- Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo, Tokyo, Japan
| | - S. Matsuda
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan
| | - T. Segawa
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan
| | - K. Seki
- Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo, Tokyo, Japan
| | - M. Shoji
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan
| | - S. W. Y. Tam
- Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan, Taiwan
| | - N. Umemura
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan
| | - B.-J. Wang
- Academia Sinica Institute of Astronomy and Astrophysics, Taipei, Taiwan
- Graduate Institute of Space Science, National Central University, Taoyuan, Taiwan
| | - S.-Y. Wang
- Academia Sinica Institute of Astronomy and Astrophysics, Taipei, Taiwan
| | - R. Redmon
- National Centers for Environmental Information, National Oceanic and Atmospheric Administration, Boulder, CO USA
| | - J. V. Rodriguez
- National Centers for Environmental Information, National Oceanic and Atmospheric Administration, Boulder, CO USA
- Cooperative Institute for Research in Environmental Sciences (CIRES) at University of Colorado at Boulder, Boulder, CO USA
| | - H. J. Singer
- Space Weather Prediction Center, National Oceanic and Atmospheric Administration, Boulder, CO USA
| | - J. Vandegriff
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - S. Abe
- International Center for Space Weather Science and Education, Kyushu University, Fukuoka, Japan
| | - M. Nose
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan
- World Data Center for Geomagnetism, Kyoto Data Analysis Center for Geomagnetism and Space Magnetism, Kyoto University, Kyoto, Japan
| | - A. Shinbori
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan
| | - Y.-M. Tanaka
- National Institute of Polar Research, Tokyo, Japan
| | - S. UeNo
- Hida Observatory, Kyoto University, Kyoto, Japan
| | - L. Andersson
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO USA
| | - P. Dunn
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - C. Fowler
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO USA
| | - J. S. Halekas
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA USA
| | - T. Hara
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - Y. Harada
- Department of Geophysics, Kyoto University, Kyoto, Japan
| | - C. O. Lee
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - R. Lillis
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - D. L. Mitchell
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - M. R. Argall
- Physics Department and Space Science Center, University of New Hampshire, Durham, NH USA
| | - K. Bromund
- NASA Goddard Space Flight Center, Greenbelt, MD USA
| | - J. L. Burch
- Southwest Research Institute, San Antonio, TX USA
| | - I. J. Cohen
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - M. Galloy
- National Center for Atmospheric Research, Boulder, CO USA
| | - B. Giles
- NASA Goddard Space Flight Center, Greenbelt, MD USA
| | - A. N. Jaynes
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA USA
| | - O. Le Contel
- Laboratoire de Physique des Plasmas, CNRS/Ecole Polytechnique/Sorbonne Université/Univ. Paris Sud/Observatoire de Paris, Paris, France
| | - M. Oka
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - T. D. Phan
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - B. M. Walsh
- Center for Space Physics, Department of Mechanical Engineering, Boston University, Boston, MA USA
| | - J. Westlake
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - F. D. Wilder
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO USA
| | - S. D. Bale
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - R. Livi
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - M. Pulupa
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - P. Whittlesey
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - A. DeWolfe
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO USA
| | - B. Harter
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO USA
| | - E. Lucas
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO USA
| | - U. Auster
- Institute for Geophysics and Extraterrestrial Physics, Technical University of Braunschweig, Braunschweig, Germany
| | - J. W. Bonnell
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - C. M. Cully
- University of Calgary, Calgary, Ontario Canada
| | - E. Donovan
- University of Calgary, Calgary, Ontario Canada
| | - R. E. Ergun
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO USA
| | - H. U. Frey
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - B. Jackel
- University of Calgary, Calgary, Ontario Canada
| | - A. Keiling
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - H. Korth
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD USA
| | - J. P. McFadden
- Space Sciences Laboratory, University of California, Berkeley, USA
| | - Y. Nishimura
- Center for Space Physics and Department of Electrical and Computer Engineering, Boston University, Boston, MA USA
| | - F. Plaschke
- Space Research Institute, Austrian Academy of Sciences, Institute of Physics, University of Graz, Graz, Austria
| | - P. Robert
- Laboratoire de Physique des Plasmas, CNRS/Ecole Polytechnique/Sorbonne Université/Univ. Paris Sud/Observatoire de Paris, Paris, France
| | | | - J. M. Weygand
- Department of Earth, Planetary and Space Sciences, and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, USA
| | - R. M. Candey
- NASA Goddard Space Flight Center, Greenbelt, MD USA
| | - R. C. Johnson
- ADNET Systems Inc., NASA Goddard Space Flight Center, Greenbelt, MD USA
| | - T. Kovalick
- ADNET Systems Inc., NASA Goddard Space Flight Center, Greenbelt, MD USA
| | - M. H. Liu
- ADNET Systems Inc., NASA Goddard Space Flight Center, Greenbelt, MD USA
| | | | - A. Breneman
- University of Minnesota, Minneapolis, MN USA
| | - K. Kersten
- University of Minnesota, Minneapolis, MN USA
| | - P. Schroeder
- Space Sciences Laboratory, University of California, Berkeley, USA
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8
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Halekas JS, Poppe AR, Harada Y, Bonnell JW, Ergun RE, McFadden JP. A Tenuous Lunar Ionosphere in the Geomagnetic Tail. Geophys Res Lett 2018; 45:9450-9459. [PMID: 33479552 PMCID: PMC7816727 DOI: 10.1029/2018gl079936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 08/30/2018] [Indexed: 06/12/2023]
Abstract
We utilize measurements of electron plasma frequency oscillations made by the two-probe Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun mission to investigate the charged particle density in the lunar environment as the Moon passes through the Earth's geomagnetic tail. We find that the Moon possesses a tenuous ionosphere with an average density of ~0.1-0.3 cm-3, present at least 50% of the time in the geomagnetic tail, primarily confined to within a few thousand kilometers of the dayside of the Moon. The day-night asymmetry and dawn-dusk symmetry of the observed plasma suggests that photoionization of a neutral exosphere with dawn-dusk symmetry produces the majority of the lunar-derived plasma. The lunar plasma density commonly exceeds the ambient plasma density in the tail, allowing the presence of the lunar ionosphere to appreciably perturb the local plasma environment.
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Affiliation(s)
- J. S. Halekas
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA, USA
| | - A. R. Poppe
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - Y. Harada
- Department of Geophysics, Kyoto University, Kyoto, Japan
| | - J. W. Bonnell
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - R. E. Ergun
- Laboratory of Atmospheric and Space Physics, University of Colorado Boulder, Boulder, CO, USA
| | - J. P. McFadden
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
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9
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Lue C, Halekas JS, Poppe AR, McFadden JP. ARTEMIS Observations of Solar Wind Proton Scattering off the Lunar Surface. J Geophys Res Space Phys 2018; 123:5289-5299. [PMID: 33479576 PMCID: PMC7816725 DOI: 10.1029/2018ja025486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 06/16/2018] [Indexed: 06/12/2023]
Abstract
We study the scattering of solar wind protons off the lunar surface, using ion observations collected over 6 years by the ARTEMIS satellites at the Moon. We show the average scattered proton energy spectra, directional scattering distributions, and scattering efficiency, for different solar wind incidence angles and impact speeds. We find that the protons have a scattering distribution that is similar to existing empirical models for scattered hydrogen energetic neutral atoms, with a peak in the backward direction (toward the Sun). We provide a revised model for the scattered proton energy spectrum. We evaluate the positive to neutral charge state ratio by comparing the proton spectrum with existing models for scattered hydrogen. The positive to neutral ratio increases with increasing exit speed from the surface but decreases with increasing impact speed. Combined, these counteracting effects result in a scattering efficiency that decreases from ~0.5% at 300 km/s solar wind speed to ~0.3% at 600 km/s solar wind speed.
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Affiliation(s)
- C. Lue
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA, USA
- Swedish Institute of Space Physics, Kiruna, Sweden
| | - J. S. Halekas
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA, USA
| | - A. R. Poppe
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - J. P. McFadden
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
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10
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Howard SK, Halekas JS, Farrell WM, McFadden JP, Glassmeier KH. Identifying Ultra Low Frequency Waves in the Lunar Plasma Environment Using Trajectory Analysisand Resonance Conditions. J Geophys Res Space Phys 2017; 122:9983-9993. [PMID: 33505827 PMCID: PMC7837453 DOI: 10.1002/2017ja024018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Recent studies show that localized crustal magnetic fields on the lunar surface can reflect a significant portion of the incoming solar wind protons. These reflected ions can drive a wide range of plasma waves. It is difficult to determine the intrinsic properties of low-frequency waves with single-spacecraft observations, which can be heavily Doppler shifted. We describe a technique to combine trajectory analysis of reflected protons with the Doppler shift and resonance conditions to identify ultralow-frequency waves at the Moon. On 31 January 2014 plasma waves were detected by one of the Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS) probes as it approached the lunar wake; these waves were not detected by the second ARTEMIS probe located upstream in the undisturbed solar wind. The observed waves had a frequency below the local ion cyclotron frequency and had right-hand circular polarization in the reference frame of the Moon. By solving the Doppler shift and the cyclotron resonance equations, we determined the conditions for reflected ions to excite the observed waves. Simulated trajectories of reflected ions correspond to ARTEMIS ion observations and support the hypothesis that reflected ions are the primary driver of the waves. By combining trajectory analysis with the resonance conditions, we identify scenarios where ions that satisfy the resonance conditions are present in the right location to generate the observed waves. Using this method, we can uniquely identify the observed waves as upstream propagating right-hand polarized waves, subject to the assumption that they are generated by cyclotron resonance with ions.
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Affiliation(s)
- S K Howard
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA, USA
| | - J S Halekas
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA, USA
| | - W M Farrell
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - J P McFadden
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - K-H Glassmeier
- Institut für Geophysik und Extraterrestrische Physik, Technische Universität Braunschweig, Braunschweig, Germany
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11
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Harada Y, Poppe AR, Halekas JS, Chamberlin PC, McFadden JP. Photoemission and electrostatic potentials on the dayside lunar surface in the terrestrial magnetotail lobes. Geophys Res Lett 2017; 44:5276-5282. [PMID: 33414571 PMCID: PMC7786453 DOI: 10.1002/2017gl073419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Despite the need to accurately predict and assess the lunar electrostatic environment in all ambient conditions that the Moon encounters, photoemission and electrostatic potentials on the dayside lunar surface in the terrestrial magnetotail lobes remain poorly characterized. We study characteristics and variabilities of lunar photoelectron energy spectra by utilizing Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS) and Apollo measurements in combination with the Flare Irradiance Spectral Model (FISM). We confirm that the photoelectron spectral shapes are consistent between ARTEMIS and Apollo and that the photoelectron flux is linearly correlated with the FISM solar photon flux. We develop an observation-based model of lunar photoelectron energy distributions, thereby deriving the current balance surface potential. The model predicts that dayside lunar surface potentials in the tail lobes (typically tens of volts) could increase by a factor of 2 - 3 during strong solar flares.
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Affiliation(s)
- Y. Harada
- Space Sciences Laboratory, University of California, Berkeley, California, USA
- Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa, USA
| | - A. R. Poppe
- Space Sciences Laboratory, University of California, Berkeley, California, USA
| | - J. S. Halekas
- Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa, USA
| | | | - J. P. McFadden
- Space Sciences Laboratory, University of California, Berkeley, California, USA
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12
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Halekas JS, Poppe AR, Lue C, Farrell WM, McFadden JP. Distribution and solar wind control of compressional solar wind-magnetic anomaly interactions observed at the Moon by ARTEMIS. J Geophys Res Space Phys 2017; 122:6240-6254. [PMID: 33479575 PMCID: PMC7816726 DOI: 10.1002/2017ja023931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A statistical investigation of 5 years of observations from the two-probe Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) mission reveals that strong compressional interactions occur infrequently at high altitudes near the ecliptic but can form in a wide range of solar wind conditions and can occur up to two lunar radii downstream from the lunar limb. The compressional events, some of which may represent small-scale collisionless shocks ("limb shocks"), occur in both steady and variable interplanetary magnetic field (IMF) conditions, with those forming in steady IMF well organized by the location of lunar remanent crustal magnetization. The events observed by ARTEMIS have similarities to ion foreshock phenomena, and those observed in variable IMF conditions may result from either local lunar interactions or distant terrestrial foreshock interactions. Observed velocity deflections associated with compressional events are always outward from the lunar wake, regardless of location and solar wind conditions. However, events for which the observed velocity deflection is parallel to the upstream motional electric field form in distinctly different solar wind conditions and locations than events with antiparallel deflections. Consideration of the momentum transfer between incoming and reflected solar wind populations helps explain the observed characteristics of the different groups of events.
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Affiliation(s)
- J. S. Halekas
- Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa, USA
- Solar System Exploration Research Virtual Institute, NASA Ames Research Center, Moffett Field, California, USA
| | - A. R. Poppe
- Solar System Exploration Research Virtual Institute, NASA Ames Research Center, Moffett Field, California, USA
- Space Sciences Laboratory, University of California, Berkeley, California, USA
| | - C. Lue
- Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa, USA
| | - W. M. Farrell
- Solar System Exploration Research Virtual Institute, NASA Ames Research Center, Moffett Field, California, USA
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - J. P. McFadden
- Space Sciences Laboratory, University of California, Berkeley, California, USA
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Poppe AR, Halekas JS, Lue C, Fatemi S. ARTEMIS observations of the solar wind proton scattering function from lunar crustal magnetic anomalies. J Geophys Res Planets 2017; 122:771-783. [PMID: 33442502 PMCID: PMC7802739 DOI: 10.1002/2017je005313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Despite their small scales, lunar crustal magnetic fields are routinely associated with observations of reflected and/or backstreaming populations of solar wind protons. Solar wind proton reflection locally reduces the rate of space weathering of the lunar regolith, depresses local sputtering rates of neutrals into the lunar exosphere, and can trigger electromagnetic waves and small-scale collisionless shocks in the near-lunar space plasma environment. Thus, knowledge of both the magnitude and scattering function of solar wind protons from magnetic anomalies is crucial in understanding a wide variety of planetary phenomena at the Moon. We have compiled 5.5 years of ARTEMIS (Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun) observations of reflected protons at the Moon and used a Liouville tracing method to ascertain each proton's reflection location and scattering angles. We find that solar wind proton reflection is largely correlated with crustal magnetic field strength, with anomalies such as South Pole/Aitken Basin (SPA), Mare Marginis, and Gerasimovich reflecting on average 5-12% of the solar wind flux while the unmagnetized surface reflects between 0.1 and 1% in charged form. We present the scattering function of solar wind protons off of the SPA anomaly, showing that the scattering transitions from isotropic at low solar zenith angles to strongly forward scattering at solar zenith angles near 90°. Such scattering is consistent with simulations that have suggested electrostatic fields as the primary mechanism for solar wind proton reflection from crustal magnetic anomalies.
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Affiliation(s)
- A. R. Poppe
- Space Sciences Laboratory, University of California, Berkeley, California, USA
- Solar System Exploration Research Virtual Institute, NASA Ames Research Center, Moffett Field, California, USA
| | - J. S. Halekas
- Solar System Exploration Research Virtual Institute, NASA Ames Research Center, Moffett Field, California, USA
- Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa, USA
| | - C. Lue
- Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa, USA
| | - S. Fatemi
- Space Sciences Laboratory, University of California, Berkeley, California, USA
- Solar System Exploration Research Virtual Institute, NASA Ames Research Center, Moffett Field, California, USA
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Halekas JS, Poppe AR, Farrell WM, McFadden JP. Structure and composition of the distant lunar exosphere: Constraints from ARTEMIS observations of ion acceleration in time-varying fields. J Geophys Res Planets 2016; 121:1102-1115. [PMID: 33479574 PMCID: PMC7816729 DOI: 10.1002/2016je005082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
By analyzing the trajectories of ionized constituents of the lunar exosphere in time-varying electromagnetic fields, we can place constraints on the composition, structure, and dynamics of the lunar exosphere. Heavy ions travel slower than light ions in the same fields, so by observing the lag between field rotations and the response of ions from the lunar exosphere, we can place constraints on the composition of the ions. Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) provides an ideal platform to utilize such an analysis, since its two-probe vantage allows precise timing of the propagation of field discontinuities in the solar wind, and its sensitive plasma instruments can detect the ion response. We demonstrate the utility of this technique by using fully time-dependent charged particle tracing to analyze several minutes of ion observations taken by the two ARTEMIS probes ~3000-5000 km above the dusk terminator on 25 January 2014. The observations from this time period allow us to reach several interesting conclusions. The ion production at altitudes of a few hundred kilometers above the sunlit surface of the Moon has an unexpectedly significant contribution from species with masses of 40 amu or greater. The inferred distribution of the neutral source population has a large scale height, suggesting that micrometeorite impact vaporization and/or sputtering play an important role in the production of neutrals from the surface. Our observations also suggest an asymmetry in ion production, consistent with either a compositional variation in neutral vapor production or a local reduction in solar wind sputtering in magnetic regions of the surface.
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Affiliation(s)
- J. S. Halekas
- Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa, USA
- Solar System Exploration Research Virtual Institute, NASA Ames Research Center, Moffett Field, California, USA
| | - A. R. Poppe
- Solar System Exploration Research Virtual Institute, NASA Ames Research Center, Moffett Field, California, USA
- Space Sciences Laboratory, University of California, Berkeley, California, USA
| | - W. M. Farrell
- Solar System Exploration Research Virtual Institute, NASA Ames Research Center, Moffett Field, California, USA
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - J. P. McFadden
- Space Sciences Laboratory, University of California, Berkeley, California, USA
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15
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Brain DA, Lillis RJ, Mitchell DL, Halekas JS, Lin RP. Electron pitch angle distributions as indicators of magnetic field topology near Mars. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2007ja012435] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- D. A. Brain
- Space Sciences Laboratory; University of California; Berkeley California USA
| | - R. J. Lillis
- Space Sciences Laboratory; University of California; Berkeley California USA
| | - D. L. Mitchell
- Space Sciences Laboratory; University of California; Berkeley California USA
| | - J. S. Halekas
- Space Sciences Laboratory; University of California; Berkeley California USA
| | - R. P. Lin
- Space Sciences Laboratory; University of California; Berkeley California USA
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16
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Leblanc F, Witasse O, Winningham J, Brain D, Lilensten J, Blelly PL, Frahm RA, Halekas JS, Bertaux JL. Origins of the Martian aurora observed by Spectroscopy for Investigation of Characteristics of the Atmosphere of Mars (SPICAM) on board Mars Express. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2006ja011763] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Halekas JS, Mitchell DL, Lin RP, Frey S, Hood LL, Acuña MH, Binder AB. Mapping of crustal magnetic anomalies on the lunar near side by the Lunar Prospector electron reflectometer. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000je001380] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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