1
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McEntee SC, Jackman CM, Weigt DM, Dunn WR, Kashyap V, Kraft R, Louis CK, Branduardi‐Raymont G, Gladstone GR, Gallagher PT. Comparing Jupiter's Equatorial X-Ray Emissions With Solar X-Ray Flux Over 19 Years of the Chandra Mission. J Geophys Res Space Phys 2022; 127:e2022JA030971. [PMID: 37032656 PMCID: PMC10078327 DOI: 10.1029/2022ja030971] [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: 09/01/2022] [Revised: 10/24/2022] [Accepted: 11/09/2022] [Indexed: 06/19/2023]
Abstract
We present a statistical study of Jupiter's disk X-ray emissions using 19 years of Chandra X-Ray Observatory (CXO) observations. Previous work has suggested that these emissions are consistent with solar X-rays elastically scattered from Jupiter's upper atmosphere. We showcase a new pulse invariant (PI) filtering method that minimizes instrumental effects which may produce unphysical trends in photon counts across the nearly two-decade span of the observations. We compare the CXO results with solar X-ray flux data from the Geostationary Operational Environmental Satellites X-ray Sensor for the wavelength band 1-8 Å (long channel), to quantify the correlation between solar activity and Jovian disk counts. We find a statistically significant Pearson's Correlation Coefficient of 0.9, which confirms that emitted Jovian disk X-rays are predominantly governed by solar activity. We also utilize the high spatial resolution of the High Resolution Camera Instrument on-board the CXO to map the disk photons to their positions on Jupiter's surface. Voronoi tessellation diagrams were constructed with the Juno Reference Model through Perijove 9 internal field model overlaid to identify any spatial preference of equatorial photons. After accounting for area and scattering across the curved surface of the planet, we find a preference of Jovian disk emission at 2-3.5 Gauss surface magnetic field strength. This suggests that a portion of the disk X-rays may be linked to processes other than solar scattering: the spatial preference associated with magnetic field strength may imply increased precipitation from the radiation belts, as previously postulated.
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Affiliation(s)
- S. C. McEntee
- School of Cosmic PhysicsDIAS Dunsink ObservatoryDublin Institute for Advanced StudiesDublinIreland
- School of PhysicsTrinity College DublinDublinIreland
| | - C. M. Jackman
- School of Cosmic PhysicsDIAS Dunsink ObservatoryDublin Institute for Advanced StudiesDublinIreland
| | - D. M. Weigt
- School of Cosmic PhysicsDIAS Dunsink ObservatoryDublin Institute for Advanced StudiesDublinIreland
| | - W. R. Dunn
- Department of Physics and AstronomyUniversity College LondonLondonUK
- Centre for Planetary Sciences at UCL/BirkbeckLondonUK
| | - V. Kashyap
- Harvard‐Smithsonian Center for AstrophysicsSmithsonian Astrophysical ObservatoryCambridgeMAUSA
| | - R. Kraft
- Harvard‐Smithsonian Center for AstrophysicsSmithsonian Astrophysical ObservatoryCambridgeMAUSA
| | - C. K. Louis
- School of Cosmic PhysicsDIAS Dunsink ObservatoryDublin Institute for Advanced StudiesDublinIreland
| | - G. Branduardi‐Raymont
- Mullard Space Science LaboratoryDepartment of Space and Climate PhysicsUniversity College LondonDorkingUK
| | - G. R. Gladstone
- Space Science and Engineering DivisionSouthwest Research InstituteSan AntonioTXUSA
- Department of Physics and AstronomyUniversity of Texas at San AntonioSan AntonioTXUSA
| | - P. T. Gallagher
- School of Cosmic PhysicsDIAS Dunsink ObservatoryDublin Institute for Advanced StudiesDublinIreland
- School of PhysicsTrinity College DublinDublinIreland
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2
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Waters JE, Jackman CM, Whiter DK, Forsyth C, Fogg AR, Lamy L, Cecconi B, Bonnin X, Issautier K. A Perspective on Substorm Dynamics Using 10 Years of Auroral Kilometric Radiation Observations From Wind. J Geophys Res Space Phys 2022; 127:e2022JA030449. [PMID: 36245707 PMCID: PMC9540659 DOI: 10.1029/2022ja030449] [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] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 08/19/2022] [Accepted: 08/23/2022] [Indexed: 06/16/2023]
Abstract
We study 10 years (1995-2004 inclusive) of auroral kilometric radiation (AKR) radio emission data from the Wind spacecraft to examine the link between AKR and terrestrial substorms. We use substorm lists based on parameters including ground magnetometer signatures and geosynchronous particle injections as a basis for superposed epoch analyses of the AKR data. The results for each list show a similar, clear response of the AKR power around substorm onset. For nearly all event lists, the average response shows that the AKR power begins to increase around 20 min prior to expansion phase onset, as defined by the respective lists. The analysis of the spectral parameters of AKR bursts show that this increase in power is due to an extension of the source region to higher altitudes, which also precedes expansion phase onset by 20 min. Our observations show that the minimum frequency channel that observes AKR at this time, on average, is 60 kHz. AKR visibility is highly sensitive to observing spacecraft location, and the biggest radio response to substorm onset is seen in the 21:00-03:00 hr local time sector.
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Affiliation(s)
- J. E. Waters
- Space Environment Physics GroupSchool of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - C. M. Jackman
- DIAS Dunsink ObservatorySchool of Cosmic PhysicsDublin Institute for Advanced StudiesDublinIreland
| | - D. K. Whiter
- Space Environment Physics GroupSchool of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - C. Forsyth
- Department of Space and Climate PhysicsMSSLUCLDorkingUK
| | - A. R. Fogg
- DIAS Dunsink ObservatorySchool of Cosmic PhysicsDublin Institute for Advanced StudiesDublinIreland
| | - L. Lamy
- Observatoire de ParisLESIAPSL Research UniversityCNRSSorbonne UniversitéUniversity of ParisMeudonFrance
- LAMPythéasAix Marseille UniversitéCNRSCNESMarseilleFrance
| | - B. Cecconi
- Observatoire de ParisLESIAPSL Research UniversityCNRSSorbonne UniversitéUniversity of ParisMeudonFrance
| | - X. Bonnin
- Observatoire de ParisLESIAPSL Research UniversityCNRSSorbonne UniversitéUniversity of ParisMeudonFrance
| | - K. Issautier
- Observatoire de ParisLESIAPSL Research UniversityCNRSSorbonne UniversitéUniversity of ParisMeudonFrance
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3
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Wu SY, Ye SY, Fischer G, Taubenschuss U, Jackman CM, O'Dwyer E, Kurth WS, Yao S, Yao ZH, Menietti JD, Xu Y, Long MY, Cecconi B. Saturn Anomalous Myriametric Radiation, a New Type of Saturn Radio Emission Revealed by Cassini. Geophys Res Lett 2022; 49:e2022GL099237. [PMID: 36249464 PMCID: PMC9541930 DOI: 10.1029/2022gl099237] [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] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/28/2022] [Accepted: 08/01/2022] [Indexed: 06/16/2023]
Abstract
A new radio component namely Saturn Anomalous Myriametric Radiation (SAM) is reported. A total of 193 SAM events have been identified by using all the Cassini Saturn orbital data. SAM emissions are L-O mode radio emission and occasionally accompanied by a first harmonic in R-X mode. SAM's intensities decrease with increasing distance from Saturn, suggesting a source near Saturn. SAM has a typical central frequency near 13 kHz, a bandwidth greater than 8 kHz and usually drifts in frequency over time. SAM's duration can extend to near 11 hr and even longer. These features distinguish SAM from the regular narrowband emissions observed in the nearby frequency range, hence the name anomalous. The high occurrence rate of SAM after low frequency extensions of Saturn Kilometric Radiation and the SAM cases observed during compressions of Saturn's magnetosphere suggest a special connection to solar wind dynamics and magnetospheric conditions at Saturn.
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Affiliation(s)
- S. Y. Wu
- Department of Earth and Space SciencesSouthern University of Science and TechnologyShenzhenPeople's Republic of China
- LESIAObservatoire de ParisUniversité PSLCNRSSorbonne UniversitéUniversité de ParisMeudonFrance
| | - S. Y. Ye
- Department of Earth and Space SciencesSouthern University of Science and TechnologyShenzhenPeople's Republic of China
| | - G. Fischer
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | - U. Taubenschuss
- Department of Space PhysicsInstitute of Atmospheric Physics of the Czech Academy of SciencesPragueCzechia
| | - C. M. Jackman
- School of Cosmic PhysicsDIAS Dunsink ObservatoryDublin Institute for Advanced StudiesDublinIreland
| | - E. O'Dwyer
- School of Cosmic PhysicsDIAS Dunsink ObservatoryDublin Institute for Advanced StudiesDublinIreland
| | - W. S. Kurth
- Department of Physics and AstronomyUniversity of IowaIowa CityIAUSA
| | - S. Yao
- School of Geophysics and Information TechnologyChina University of Geosciences (Beijing)BeijingPeople's Republic of China
| | - Z. H. Yao
- Key Laboratory of Earth and Planetary PhysicsInstitute of Geology and GeophysicsChinese Academy of SciencesBeijingPeople's Republic of China
| | - J. D. Menietti
- Department of Physics and AstronomyUniversity of IowaIowa CityIAUSA
| | - Y. Xu
- Key Laboratory of Earth and Planetary PhysicsInstitute of Geology and GeophysicsChinese Academy of SciencesBeijingPeople's Republic of China
| | - M. Y. Long
- Department of Space PhysicsSchool of Electronic InformationWuhan UniversityWuhanPeople's Republic of China
| | - B. Cecconi
- LESIAObservatoire de ParisUniversité PSLCNRSSorbonne UniversitéUniversité de ParisMeudonFrance
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4
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Dunn WR, Weigt DM, Grodent D, Yao ZH, May D, Feigelman K, Sipos B, Fleming D, McEntee S, Bonfond B, Gladstone GR, Johnson RE, Jackman CM, Guo RL, Branduardi‐Raymont G, Wibisono AD, Kraft RP, Nichols JD, Ray LC. Jupiter's X-Ray and UV Dark Polar Region. Geophys Res Lett 2022; 49:e2021GL097390. [PMID: 35865009 PMCID: PMC9287093 DOI: 10.1029/2021gl097390] [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: 12/16/2021] [Revised: 05/18/2022] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
We present 14 simultaneous Chandra X-ray Observatory (CXO)-Hubble Space Telescope (HST) observations of Jupiter's Northern X-ray and ultraviolet (UV) aurorae from 2016 to 2019. Despite the variety of dynamic UV and X-ray auroral structures, one region is conspicuous by its persistent absence of emission: the dark polar region (DPR). Previous HST observations have shown that very little UV emission is produced by the DPR. We find that the DPR also produces very few X-ray photons. For all 14 observations, the low level of X-ray emission from the DPR is consistent (within 2-standard deviations) with scattered solar emission and/or photons spread by Chandra's Point Spread Function from known X-ray-bright regions. We therefore conclude that for these 14 observations the DPR produced no statistically significant detectable X-ray signature.
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Affiliation(s)
- W. R. Dunn
- Mullard Space Science LaboratoryUniversity College LondonDorkingUK
- The Centre for Planetary Science at UCL/BirkbeckLondonUK
| | - D. M. Weigt
- School of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
- School of PhysicsTrinity College DublinDublinIreland
| | - D. Grodent
- Laboratoire de Physique Atmosphérique et PlanétaireSTAR InstituteUniversité de LiègeLiègeBelgium
| | - Z. H. Yao
- Key Laboratory of Earth and Planetary PhysicsInstitute of Geology and GeophysicsChinese Academy of SciencesBeijingChina
- College of Earth and Planetary SciencesUniversity of Chinese Academy of SciencesBeijingChina
| | - D. May
- Department of ScienceSt. Gilgen International SchoolSt. GilgenAustria
| | - K. Feigelman
- Department of ScienceSt. Gilgen International SchoolSt. GilgenAustria
| | - B. Sipos
- Department of ScienceSt. Gilgen International SchoolSt. GilgenAustria
| | - D. Fleming
- Department of ScienceSt. Gilgen International SchoolSt. GilgenAustria
| | - S. McEntee
- School of PhysicsTrinity College DublinDublinIreland
- School of Cosmic PhysicsDIAS Dunsink ObservatoryDublin Institute for Advanced StudiesDublinIreland
| | - B. Bonfond
- Laboratoire de Physique Atmosphérique et PlanétaireSTAR InstituteUniversité de LiègeLiègeBelgium
| | - G. R. Gladstone
- Division of Space Science and EngineeringSouthwest Research InstituteSan AntonioTXUSA
- Department of Physics and AstronomyUniversity of Texas at San AntonioSan AntonioTXUSA
| | - R. E. Johnson
- Department of PhysicsAberystwyth UniversityCeredigionUK
| | - C. M. Jackman
- School of Cosmic PhysicsDIAS Dunsink ObservatoryDublin Institute for Advanced StudiesDublinIreland
| | - R. L. Guo
- Laboratory of Optical Astronomy and Solar‐Terrestrial EnvironmentSchool of Space Science and PhysicsInstitute of Space SciencesShandong UniversityWeihaiChina
| | - G. Branduardi‐Raymont
- Mullard Space Science LaboratoryUniversity College LondonDorkingUK
- The Centre for Planetary Science at UCL/BirkbeckLondonUK
| | - A. D. Wibisono
- Mullard Space Science LaboratoryUniversity College LondonDorkingUK
- The Centre for Planetary Science at UCL/BirkbeckLondonUK
| | - R. P. Kraft
- Harvard‐Smithsonian Center for AstrophysicsSmithsonian Astrophysical ObservatoryCambridgeMAUSA
| | - J. D. Nichols
- Department of Physics and AstronomyUniversity of LeicesterLeicesterUK
| | - L. C. Ray
- Department of PhysicsLancaster UniversityLancasterUK
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5
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Wu SY, Ye SY, Fischer G, Jackman CM, Wang J, Menietti JD, Cecconi B, Long MY. Reflection and Refraction of the L-O Mode 5 kHz Saturn Narrowband Emission by the Magnetosheath. Geophys Res Lett 2022; 49:e2021GL096990. [PMID: 35859935 PMCID: PMC9285440 DOI: 10.1029/2021gl096990] [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] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/10/2022] [Accepted: 02/12/2022] [Indexed: 06/15/2023]
Abstract
The reflection-by-sheath mechanism of 5 kHz narrowband emissions (NB) at Saturn is confirmed by Cassini observations during several crossings of the magnetopause, which show that the 5 kHz NB can be prevented from escaping Saturn's magnetosphere. The L-O mode 5 kHz NB remained visible in areas of low plasma density but disappeared in regions of high plasma density. In three cases, NB disappeared immediately after the crossings of Saturn's magnetopause. A possible reflected NB event observed near the magnetosheath is discussed. This mechanism can help explain the 5 kHz NB observed at low latitudes outside the Enceladus plasma torus and their upper frequency limit variations. This mechanism significantly improves the current understanding of the 5 kHz NB.
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Affiliation(s)
- S. Y. Wu
- Department of Earth and Space SciencesSouthern University of Science and TechnologyShenzhenPeople's Republic of China
| | - S. Y. Ye
- Department of Earth and Space SciencesSouthern University of Science and TechnologyShenzhenPeople's Republic of China
| | - G. Fischer
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | - C. M. Jackman
- School of Cosmic PhysicsDublin Institute for Advanced StudiesDublinIreland
| | - J. Wang
- Department of Earth and Space SciencesSouthern University of Science and TechnologyShenzhenPeople's Republic of China
| | - J. D. Menietti
- Department of Physics and AstronomyUniversity of IowaIowa CityIAUSA
| | - B. Cecconi
- LESIA, Observatoire de ParisUniversité PSLCNRSSorbonne UniversitéUniversité de Paris MeudonParisFrance
| | - M. Y. Long
- Department of Space PhysicsSchool of Electronic InformationWuhan UniversityWuhanPeople's Republic of China
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6
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Morrissey CK, Bledsoe AD, Zimmerman J, Bott SI, Stuart AR, Johnson KB, DeCou JA, Thackeray EM, Kuck K, Chacin AB, Dorsey DP, Chortkoff B, Drennan EL, Smith DW, Jackman CM, Paulsen LF, Egan TD. Reinvention of an academic anaesthesiology department during pandemic times: lessons learnt and adapting to a “new normal”. Southern African Journal of Anaesthesia and Analgesia 2021. [DOI: 10.36303/sajaa.2021.27.3.2576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- CK Morrissey
- Department of Anesthesiology, University of Utah,
United States of America
| | - AD Bledsoe
- Department of Anesthesiology, University of Utah,
United States of America
| | - J Zimmerman
- Department of Anesthesiology, University of Utah,
United States of America
| | - SI Bott
- Department of Anesthesiology, University of Utah,
United States of America
| | - AR Stuart
- Department of Anesthesiology, University of Utah,
United States of America
| | - KB Johnson
- Department of Anesthesiology, University of Utah,
United States of America
| | - JA DeCou
- Department of Anesthesiology, University of Utah,
United States of America
| | - EM Thackeray
- Department of Anesthesiology, University of Utah,
United States of America
| | - K Kuck
- Department of Anesthesiology, University of Utah,
United States of America
| | - AB Chacin
- Department of Anesthesiology, University of Utah,
United States of America
| | - DP Dorsey
- Department of Anesthesiology, University of Utah,
United States of America
| | - B Chortkoff
- Department of Anesthesiology, University of Utah,
United States of America
| | - EL Drennan
- Department of Anesthesiology, University of Utah,
United States of America
| | - DW Smith
- Department of Anesthesiology, University of Utah,
United States of America
| | - CM Jackman
- Department of Anesthesiology, University of Utah,
United States of America
| | - LF Paulsen
- Department of Anesthesiology, University of Utah,
United States of America
| | - TD Egan
- Department of Anesthesiology, University of Utah,
United States of America
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7
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Smith AW, Jackman CM, Frohmaier CM, Coxon JC, Slavin JA, Fear RC. Evaluating Single-Spacecraft Observations of Planetary Magnetotails With Simple Monte Carlo Simulations: 1. Spatial Distributions of the Neutral Line. J Geophys Res Space Phys 2018; 123:10109-10123. [PMID: 31008003 PMCID: PMC6472645 DOI: 10.1029/2018ja025958] [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] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/26/2018] [Accepted: 12/01/2018] [Indexed: 06/09/2023]
Abstract
A simple Monte Carlo model is presented that considers the effects of spacecraft orbital sampling on the inferred distribution of magnetic flux ropes, generated through magnetic reconnection in the magnetotail current sheet. When generalized, the model allows the determination of the number of orbits required to constrain the underlying population of structures: It is able to quantify this as a function of the physical parameters of the structures (e.g., azimuthal extent and probability of generation). The model is shown adapted to the Hermean magnetotail, where the outputs are compared to the results of a recent survey. This comparison suggests that the center of Mercury's neutral line is located dawnward of midnight by 0 . 3 7 - 1 . 02 + 1 . 21 R M and that the flux ropes are most likely to be wide azimuthally (∼50% of the width of the Hermean tail). The downtail location of the neutral line is not self-consistent or in agreement with previous (independent) studies unless dissipation terms are included planetward of the reconnection site; potential physical explanations are discussed. In the future the model could be adapted to other environments, for example, the dayside magnetopause or other planetary magnetotails.
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Affiliation(s)
- A. W. Smith
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - C. M. Jackman
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - C. M. Frohmaier
- Institute of Cosmology and GravitationUniversity of PortsmouthPortsmouthUK
| | - J. C. Coxon
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - J. A. Slavin
- Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
| | - R. C. Fear
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
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8
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Smith AW, Jackman CM, Frohmaier CM, Fear RC, Slavin JA, Coxon JC. Evaluating Single Spacecraft Observations of Planetary Magnetotails With Simple Monte Carlo Simulations: 2. Magnetic Flux Rope Signature Selection Effects. J Geophys Res Space Phys 2018; 123:10124-10138. [PMID: 31008004 PMCID: PMC6472627 DOI: 10.1029/2018ja025959] [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] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/25/2018] [Accepted: 11/20/2018] [Indexed: 06/09/2023]
Abstract
A Monte Carlo method of investigating the effects of placing selection criteria on the magnetic signature of in situ encounters with flux ropes is presented. The technique is applied to two recent flux rope surveys of MESSENGER data within the Hermean magnetotail. It is found that the different criteria placed upon the signatures will preferentially identify slightly different subsets of the underlying population. Quantifying the selection biases first allows the distributions of flux rope parameters to be corrected, allowing a more accurate estimation of the intrinsic distributions. This is shown with regard to the distribution of flux rope radii observed. When accounting for the selection criteria, the mean radius of Hermean magnetotail quasi-force-free flux ropes is found to be 58 9 - 269 + 273 km. Second, it is possible to weight the known identifications in order to determine a rate of recurrence that accounts for the presence of the structures that will not be identified. In the case of the Hermean magnetotail, the average rate of quasi-force-free flux ropes is found to 0.12 min-1 when selection effects are accounted for (up from 0.05 min-1 previously inferred from observations).
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Affiliation(s)
- A. W. Smith
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - C. M. Jackman
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - C. M. Frohmaier
- Institute of Cosmology and GravitationUniversity of PortsmouthPortsmouthUK
| | - R. C. Fear
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - J. A. Slavin
- Climate and Space Sciences and EngineeringUniversity of MichiganAnn ArborMIUSA
| | - J. C. Coxon
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
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9
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Sandhu JK, Rae IJ, Freeman MP, Forsyth C, Gkioulidou M, Reeves GD, Spence HE, Jackman CM, Lam MM. Energization of the Ring Current by Substorms. J Geophys Res Space Phys 2018; 123:8131-8148. [PMID: 30775195 PMCID: PMC6360953 DOI: 10.1029/2018ja025766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/10/2018] [Accepted: 09/12/2018] [Indexed: 06/01/2023]
Abstract
The substorm process releases large amounts of energy into the magnetospheric system, although where the energy is transferred to and how it is partitioned remains an open question. In this study, we address whether the substorm process contributes a significant amount of energy to the ring current. The ring current is a highly variable region, and understanding the energization processes provides valuable insight into how substorm-ring current coupling may contribute to the generation of storm conditions and provide a source of energy for wave driving. In order to quantify the energy input into the ring current during the substorm process, we analyze Radiation Belt Storm Probes Ion Composition Experiment and Helium Oxygen Proton Electron ion flux measurements for H+, O+, and He+. The energy content of the ring current is estimated and binned spatially for L and magnetic local time. The results are combined with an independently derived substorm event list to perform a statistical analysis of variations in the ring current energy content with substorm phase. We show that the ring current energy is significantly higher in the expansion phase compared to the growth phase, with the energy enhancement persisting into the substorm recovery phase. The characteristics of the energy enhancement suggest the injection of energized ions from the tail plasma sheet following substorm onset. The local time variations indicate a loss of energetic H+ ions in the afternoon sector, likely due to wave-particle interactions. Overall, we find that the average energy input into the ring current is ∼9% of the previously reported energy released during substorms.
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Affiliation(s)
- J. K. Sandhu
- Department of Space and Climate Physics, Mullard Space Science LaboratoryUniversity College LondonLondonUK
| | - I. J. Rae
- Department of Space and Climate Physics, Mullard Space Science LaboratoryUniversity College LondonLondonUK
| | | | - C. Forsyth
- Department of Space and Climate Physics, Mullard Space Science LaboratoryUniversity College LondonLondonUK
| | - M. Gkioulidou
- Applied Physics LaboratoryJohns Hopkins UniversityBaltimoreMDUSA
| | | | - H. E. Spence
- Institute for the Study of Earth, Oceans, and SpaceUniversity of New HampshireDurhamNHUSA
| | - C. M. Jackman
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - M. M. Lam
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
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10
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Forsyth C, Rae IJ, Murphy KR, Freeman MP, Huang C, Spence HE, Boyd AJ, Coxon JC, Jackman CM, Kalmoni NME, Watt CEJ. What effect do substorms have on the content of the radiation belts? J Geophys Res Space Phys 2016; 121:6292-6306. [PMID: 27656336 PMCID: PMC5014235 DOI: 10.1002/2016ja022620] [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] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 06/06/2016] [Accepted: 06/08/2016] [Indexed: 06/01/2023]
Abstract
Substorms are fundamental and dynamic processes in the magnetosphere, converting captured solar wind magnetic energy into plasma energy. These substorms have been suggested to be a key driver of energetic electron enhancements in the outer radiation belts. Substorms inject a keV "seed" population into the inner magnetosphere which is subsequently energized through wave-particle interactions up to relativistic energies; however, the extent to which substorms enhance the radiation belts, either directly or indirectly, has never before been quantified. In this study, we examine increases and decreases in the total radiation belt electron content (TRBEC) following substorms and geomagnetically quiet intervals. Our results show that the radiation belts are inherently lossy, shown by a negative median change in TRBEC at all intervals following substorms and quiet intervals. However, there are up to 3 times as many increases in TRBEC following substorm intervals. There is a lag of 1-3 days between the substorm or quiet intervals and their greatest effect on radiation belt content, shown in the difference between the occurrence of increases and losses in TRBEC following substorms and quiet intervals, the mean change in TRBEC following substorms or quiet intervals, and the cross correlation between SuperMAG AL (SML) and TRBEC. However, there is a statistically significant effect on the occurrence of increases and decreases in TRBEC up to a lag of 6 days. Increases in radiation belt content show a significant correlation with SML and SYM-H, but decreases in the radiation belt show no apparent link with magnetospheric activity levels.
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Affiliation(s)
- C. Forsyth
- Mullard Space Science LaboratoryUniversity College LondonDorkingUK
| | - I. J. Rae
- Mullard Space Science LaboratoryUniversity College LondonDorkingUK
| | - K. R. Murphy
- NASA Goddard Space Flight CenterGreenbeltMarylandUSA
| | | | - C.‐L. Huang
- Space Science CenterUniversity of New HampshireDurhamNew HampshireUSA
| | - H. E. Spence
- Space Science CenterUniversity of New HampshireDurhamNew HampshireUSA
| | - A. J. Boyd
- Space Science CenterUniversity of New HampshireDurhamNew HampshireUSA
- New Mexico ConsortiumLos AlamosNew MexicoUSA
| | - J. C. Coxon
- School of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - C. M. Jackman
- School of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - N. M. E. Kalmoni
- Mullard Space Science LaboratoryUniversity College LondonDorkingUK
| | - C. E. J. Watt
- Department of MeteorologyUniversity of ReadingReadingUK
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11
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Smith AW, Jackman CM, Thomsen MF. Magnetic reconnection in Saturn's magnetotail: A comprehensive magnetic field survey. J Geophys Res Space Phys 2016; 121:2984-3005. [PMID: 27867795 PMCID: PMC5111619 DOI: 10.1002/2015ja022005] [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] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 02/01/2016] [Accepted: 03/03/2016] [Indexed: 05/04/2023]
Abstract
Reconnection within planetary magnetotails is responsible for locally energizing particles and changing the magnetic topology. Its role in terms of global magnetospheric dynamics can involve changing the mass and flux content of the magnetosphere. We have identified reconnection related events in spacecraft magnetometer data recorded during Cassini's exploration of Saturn's magnetotail. The events are identified from deflections in the north-south component of the magnetic field, significant above a background level. Data were selected to provide full tail coverage, encompassing the dawn and dusk flanks as well as the deepest midnight orbits. Overall 2094 reconnection related events were identified, with an average rate of 5.0 events per day. The majority of events occur in clusters (within 3 h of other events). We examine changes in this rate in terms of local time and latitude coverage, taking seasonal effects into account. The observed reconnection rate peaks postmidnight with more infrequent but steady loss seen on the dusk flank. We estimate the mass loss from the event catalog and find it to be insufficient to balance the input from the moon Enceladus. Several reasons for this discrepancy are discussed. The reconnection X line location appears to be highly variable, though a statistical separation between events tailward and planetward of the X line is observed at a radial distance of between 20 and 30RS downtail. The small sample size at dawn prevents comprehensive statistical comparison with the dusk flank observations in terms of flux closure.
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Affiliation(s)
- A. W. Smith
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - C. M. Jackman
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
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Felici M, Arridge CS, Coates AJ, Badman SV, Dougherty MK, Jackman CM, Kurth WS, Melin H, Mitchell DG, Reisenfeld DB, Sergis N. Cassini observations of ionospheric plasma in Saturn's magnetotail lobes. J Geophys Res Space Phys 2016; 121:338-357. [PMID: 27610291 PMCID: PMC4994772 DOI: 10.1002/2015ja021648] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 12/13/2015] [Accepted: 12/28/2015] [Indexed: 05/20/2023]
Abstract
Studies of Saturn's magnetosphere with the Cassini mission have established the importance of Enceladus as the dominant mass source for Saturn's magnetosphere. It is well known that the ionosphere is an important mass source at Earth during periods of intense geomagnetic activity, but lesser attention has been dedicated to study the ionospheric mass source at Saturn. In this paper we describe a case study of data from Saturn's magnetotail, when Cassini was located at ≃ 2200 h Saturn local time at 36 RS from Saturn. During several entries into the magnetotail lobe, tailward flowing cold electrons and a cold ion beam were observed directly adjacent to the plasma sheet and extending deeper into the lobe. The electrons and ions appear to be dispersed, dropping to lower energies with time. The composition of both the plasma sheet and lobe ions show very low fluxes (sometimes zero within measurement error) of water group ions. The magnetic field has a swept-forward configuration which is atypical for this region, and the total magnetic field strength is larger than expected at this distance from the planet. Ultraviolet auroral observations show a dawn brightening, and upstream heliospheric models suggest that the magnetosphere is being compressed by a region of high solar wind ram pressure. We interpret this event as the observation of ionospheric outflow in Saturn's magnetotail. We estimate a number flux between (2.95 ± 0.43) × 109 and (1.43 ± 0.21) × 1010 cm-2 s-1, 1 or about 2 orders of magnitude larger than suggested by steady state MHD models, with a mass source between 1.4 ×102 and 1.1 ×103 kg/s. After considering several configurations for the active atmospheric regions, we consider as most probable the main auroral oval, with associated mass source between 49.7 ±13.4 and 239.8 ±64.8 kg/s for an average auroral oval, and 10 ±4 and 49 ±23 kg/s for the specific auroral oval morphology found during this event. It is not clear how much of this mass is trapped within the magnetosphere and how much is lost to the solar wind.
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Affiliation(s)
- M. Felici
- Mullard Space Science LaboratoryUniversity College LondonDorkingUK
- Centre for Planetary Sciences at UCL/BirkbeckLondonUK
- Department of PhysicsLancaster UniversityLancasterUK
| | - C. S. Arridge
- Department of PhysicsLancaster UniversityLancasterUK
| | - A. J. Coates
- Mullard Space Science LaboratoryUniversity College LondonDorkingUK
- Centre for Planetary Sciences at UCL/BirkbeckLondonUK
| | - S. V. Badman
- Department of PhysicsLancaster UniversityLancasterUK
| | - M. K. Dougherty
- Space and Atmospheric Physics Group, The Blackett LaboratoryImperial College LondonLondonUK
| | - C. M. Jackman
- Department of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | - W. S. Kurth
- Department of Physics and AstronomyUniversity of IowaIowa CityIowaUSA
| | - H. Melin
- Department of Physics and AstronomyUniversity of LeicesterLeicesterUK
| | - D. G. Mitchell
- The Johns Hopkins University Applied Physics LaboratoryLaurelMarylandUSA
| | - D. B. Reisenfeld
- Department of Physics and AstronomyUniversity of MontanaMissoulaMontanaUSA
| | - N. Sergis
- Mullard Space Science LaboratoryUniversity College LondonDorkingUK
- Office for Space ResearchAcademy of AthensAthensGreece
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Jackman CM, Thomsen MF, Mitchell DG, Sergis N, Arridge CS, Felici M, Badman SV, Paranicas C, Jia X, Hospodarksy GB, Andriopoulou M, Khurana KK, Smith AW, Dougherty MK. Field dipolarization in Saturn's magnetotail with planetward ion flows and energetic particle flow bursts: Evidence of quasi-steady reconnection. J Geophys Res Space Phys 2015; 120:3603-3617. [PMID: 27570722 PMCID: PMC4981121 DOI: 10.1002/2015ja020995] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 04/01/2015] [Accepted: 04/01/2015] [Indexed: 05/20/2023]
Abstract
We present a case study of an event from 20 August (day 232) of 2006, when the Cassini spacecraft was sampling the region near 32 RS and 22 h LT in Saturn's magnetotail. Cassini observed a strong northward-to-southward turning of the magnetic field, which is interpreted as the signature of dipolarization of the field as seen by the spacecraft planetward of the reconnection X line. This event was accompanied by very rapid (up to ~1500 km s-1) thermal plasma flow toward the planet. At energies above 28 keV, energetic hydrogen and oxygen ion flow bursts were observed to stream planetward from a reconnection site downtail of the spacecraft. Meanwhile, a strong field-aligned beam of energetic hydrogen was also observed to stream tailward, likely from an ionospheric source. Saturn kilometric radiation emissions were stimulated shortly after the observation of the dipolarization. We discuss the field, plasma, energetic particle, and radio observations in the context of the impact this reconnection event had on global magnetospheric dynamics.
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Affiliation(s)
- C. M. Jackman
- School of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
| | | | - D. G. Mitchell
- The Johns Hopkins University Applied Physics LaboratoryLaurelMarylandUSA
| | | | | | - M. Felici
- Department of PhysicsLancaster UniversityBailriggUK
- Mullard Space Science LaboratoryUniversity College LondonSurreyUK
- The Centre for Planetary Sciences at UCL/BirkbeckLondonUK
| | - S. V. Badman
- Department of PhysicsLancaster UniversityBailriggUK
| | - C. Paranicas
- The Johns Hopkins University Applied Physics LaboratoryLaurelMarylandUSA
| | - X. Jia
- Atmospheric, Oceanic and Space SciencesUniversity of MichiganAnn ArborMichiganUSA
| | - G. B. Hospodarksy
- Department of Physics and AstronomyUniversity of IowaIowa CityIowaUSA
| | - M. Andriopoulou
- Space Research InstituteAustrian Academy of SciencesGrazAustria
| | - K. K. Khurana
- Institute of Geophysics and Planetary PhysicsUniversity of CaliforniaLos AngelesCaliforniaUSA
| | - A. W. Smith
- School of Physics and AstronomyUniversity of SouthamptonSouthamptonUK
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Forsyth C, Watt CEJ, Rae IJ, Fazakerley AN, Kalmoni NME, Freeman MP, Boakes PD, Nakamura R, Dandouras I, Kistler LM, Jackman CM, Coxon JC, Carr CM. Increases in plasma sheet temperature with solar wind driving during substorm growth phases. Geophys Res Lett 2014; 41:8713-8721. [PMID: 26074645 PMCID: PMC4459207 DOI: 10.1002/2014gl062400] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 11/27/2014] [Indexed: 06/02/2023]
Abstract
During substorm growth phases, magnetic reconnection at the magnetopause extracts ∼1015 J from the solar wind which is then stored in the magnetotail lobes. Plasma sheet pressure increases to balance magnetic flux density increases in the lobes. Here we examine plasma sheet pressure, density, and temperature during substorm growth phases using 9 years of Cluster data (>316,000 data points). We show that plasma sheet pressure and temperature are higher during growth phases with higher solar wind driving, whereas the density is approximately constant. We also show a weak correlation between plasma sheet temperature before onset and the minimum SuperMAG AL (SML) auroral index in the subsequent substorm. We discuss how energization of the plasma sheet before onset may result from thermodynamically adiabatic processes; how hotter plasma sheets may result in magnetotail instabilities, and how this relates to the onset and size of the subsequent substorm expansion phase.
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Affiliation(s)
- C Forsyth
- UCL Mullard Space Science LaboratoryDorking, UK
| | - C E J Watt
- Department of Meteorology, University of ReadingReading, UK
| | - I J Rae
- UCL Mullard Space Science LaboratoryDorking, UK
| | | | | | | | - P D Boakes
- Space Research Institute, Austrian Academy of SciencesGraz, Austria
| | - R Nakamura
- Space Research Institute, Austrian Academy of SciencesGraz, Austria
| | - I Dandouras
- Institut de Recherche en Astrophysique et Planétologie, University of ToulouseToulouse, France
- CNRS, IRAPToulouse, France
| | - L M Kistler
- Space Science Centre, Morse Hall, University of New HampshireDurham, New Hampshire, USA
| | - C M Jackman
- School of Physics & Astronomy, University of SouthamptonSouthampton, UK
| | - J C Coxon
- Department Physics and Astronomy, University of LeicesterLeicester, UK
| | - C M Carr
- Department of Physics, Imperial College LondonLondon, UK
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Provan G, Andrews DJ, Arridge CS, Coates AJ, Cowley SWH, Cox G, Dougherty MK, Jackman CM. Dual periodicities in planetary-period magnetic field oscillations in Saturn's tail. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011ja017104] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [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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Arridge CS, André N, Khurana KK, Russell CT, Cowley SWH, Provan G, Andrews DJ, Jackman CM, Coates AJ, Sittler EC, Dougherty MK, Young DT. Periodic motion of Saturn's nightside plasma sheet. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011ja016827] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [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)
- C. S. Arridge
- Mullard Space Science Laboratory; University College London; Dorking UK
- Centre for Planetary Sciences at UCL/Birkbeck; London UK
| | - N. André
- Institut de Recherche en Astrophysique et Planétologie; CNRS; Toulouse France
- Institut de Recherche en Astrophysique et Planétologie; Université de Toulouse, UPS-OMP; Toulouse France
| | - K. K. Khurana
- Institute for Geophysics and Planetary Physics; University of California; Los Angeles California USA
| | - C. T. Russell
- Institute for Geophysics and Planetary Physics; University of California; Los Angeles California USA
| | - S. W. H. Cowley
- Department of Physics and Astronomy; University of Leicester; Leicester UK
| | - G. Provan
- Department of Physics and Astronomy; University of Leicester; Leicester UK
| | - D. J. Andrews
- Department of Physics and Astronomy; University of Leicester; Leicester UK
| | - C. M. Jackman
- Centre for Planetary Sciences at UCL/Birkbeck; London UK
- Blackett Laboratory; Imperial College London; London UK
- Department of Physics and Astronomy; University College London; London UK
| | - A. J. Coates
- Mullard Space Science Laboratory; University College London; Dorking UK
- Centre for Planetary Sciences at UCL/Birkbeck; London UK
| | - E. C. Sittler
- NASA Goddard Space Flight Center; Greenbelt Maryland USA
| | | | - D. T. Young
- Southwest Research Institute; San Antonio Texas USA
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Jackman CM, Slavin JA, Cowley SWH. Cassini observations of plasmoid structure and dynamics: Implications for the role of magnetic reconnection in magnetospheric circulation at Saturn. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011ja016682] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [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)
- C. M. Jackman
- Department of Physics and Astronomy; University College London; London UK
| | - J. A. Slavin
- NASA Goddard Space Flight Center; Greenbelt Maryland USA
| | - S. W. H. Cowley
- Department of Physics and Astronomy; University of Leicester; Leicester UK
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Affiliation(s)
- C. M. Jackman
- Blackett Laboratory; Imperial College London; London UK
| | - C. S. Arridge
- Mullard Space Science Laboratory; University College London; Dorking UK
- Centre for Planetary Sciences at UCL/Birkbeck; London UK
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Kollmann P, Roussos E, Paranicas C, Krupp N, Jackman CM, Kirsch E, Glassmeier KH. Energetic particle phase space densities at Saturn: Cassini observations and interpretations. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010ja016221] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- P. Kollmann
- Max Planck Institute for Solar System Research; Katlenburg-Lindau Germany
- Institut für Geophysik und Extraterrestrische Physik; Technische Universität Braunschweig; Braunschweig Germany
| | - E. Roussos
- Max Planck Institute for Solar System Research; Katlenburg-Lindau Germany
| | - C. Paranicas
- Johns Hopkins University Applied Physics Laboratory; Laurel Maryland USA
| | - N. Krupp
- Max Planck Institute for Solar System Research; Katlenburg-Lindau Germany
| | - C. M. Jackman
- Department of Physics and Astronomy; University College London; London UK
| | - E. Kirsch
- Max Planck Institute for Solar System Research; Katlenburg-Lindau Germany
| | - K.-H. Glassmeier
- Max Planck Institute for Solar System Research; Katlenburg-Lindau Germany
- Institut für Geophysik und Extraterrestrische Physik; Technische Universität Braunschweig; Braunschweig Germany
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Jackman CM, Arridge CS, Slavin JA, Milan SE, Lamy L, Dougherty MK, Coates AJ. In situ observations of the effect of a solar wind compression on Saturn's magnetotail. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010ja015312] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [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)
- C. M. Jackman
- Blackett Laboratory; Imperial College London; London UK
| | - C. S. Arridge
- Mullard Space Science Laboratory, Department of Space and Climate Physics; University College London; Dorking UK
- The Centre for Planetary Sciences at UCL/Birkbeck; London UK
| | - J. A. Slavin
- Heliophysics Science Division; NASA Goddard Space Flight Center; Greenbelt Maryland USA
| | - S. E. Milan
- Radio and Space Plasma Physics Group; University of Leicester; Leicester UK
| | - L. Lamy
- Blackett Laboratory; Imperial College London; London UK
| | | | - A. J. Coates
- Mullard Space Science Laboratory, Department of Space and Climate Physics; University College London; Dorking UK
- The Centre for Planetary Sciences at UCL/Birkbeck; London UK
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Jackman CM, Lamy L, Freeman MP, Zarka P, Cecconi B, Kurth WS, Cowley SWH, Dougherty MK. On the character and distribution of lower-frequency radio emissions at Saturn and their relationship to substorm-like events. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008ja013997] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- C. M. Jackman
- Blackett Laboratory; Imperial College London; London UK
| | - L. Lamy
- LESIA, Observatoire de Paris; Université Paris Diderot, UPMC, CNRS; Meudon France
| | | | - P. Zarka
- LESIA, Observatoire de Paris; Université Paris Diderot, UPMC, CNRS; Meudon France
| | - B. Cecconi
- LESIA, Observatoire de Paris; Université Paris Diderot, UPMC, CNRS; Meudon France
| | - W. S. Kurth
- Department of Physics and Astronomy; University of Iowa; Iowa City Iowa USA
| | - S. W. H. Cowley
- Department of Physics and Astronomy; University of Leicester; Leicester UK
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Jackman CM, Arridge CS, Krupp N, Bunce EJ, Mitchell DG, McAndrews HJ, Dougherty MK, Russell CT, Achilleos N, Jones GH, Coates AJ. A multi-instrument view of tail reconnection at Saturn. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2008ja013592] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [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)
- C. M. Jackman
- Space and Atmospheric Physics Group; Imperial College London; London UK
| | - C. S. Arridge
- Mullard Space Science Laboratory; University College London; Surrey UK
- Centre for Planetary Sciences; University College London; London UK
| | - N. Krupp
- Max Planck Institute for Solar System Research; Katlenburg-Lindau Germany
| | - E. J. Bunce
- Department of Physics and Astronomy; University of Leicester; Leicester UK
| | - D. G. Mitchell
- Applied Physics Laboratory; Johns Hopkins University; Baltimore Maryland USA
| | | | - M. K. Dougherty
- Space and Atmospheric Physics Group; Imperial College London; London UK
| | - C. T. Russell
- Institute of Geophysics and Planetary Physics; University of California; Los Angeles California USA
| | - N. Achilleos
- Centre for Planetary Sciences; University College London; London UK
- Department of Physics and Astronomy; University College London; London UK
| | - G. H. Jones
- Mullard Space Science Laboratory; University College London; Surrey UK
- Centre for Planetary Sciences; University College London; London UK
| | - A. J. Coates
- Mullard Space Science Laboratory; University College London; Surrey UK
- Centre for Planetary Sciences; University College London; London UK
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Achilleos N, Arridge CS, Bertucci C, Jackman CM, Dougherty MK, Khurana KK, Russell CT. Large-scale dynamics of Saturn's magnetopause: Observations by Cassini. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2008ja013265] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [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)
- N. Achilleos
- Atmospheric Physics Laboratory, Center for Planetary Sciences; University College London; London UK
- Blackett Laboratory; Imperial College London; London UK
| | - C. S. Arridge
- Blackett Laboratory; Imperial College London; London UK
- Mullard Space Science Laboratory, Center for Planetary Sciences; University College London, Holmbury St Mary; London UK
| | - C. Bertucci
- Blackett Laboratory; Imperial College London; London UK
| | - C. M. Jackman
- Blackett Laboratory; Imperial College London; London UK
| | | | - K. K. Khurana
- Institute of Geophysics and Planetary Physics; University of California-Los Angeles; Los Angeles California USA
| | - C. T. Russell
- Institute of Geophysics and Planetary Physics; University of California-Los Angeles; Los Angeles California USA
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Jackman CM, Forsyth RJ, Dougherty MK. The overall configuration of the interplanetary magnetic field upstream of Saturn as revealed by Cassini observations. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2008ja013083] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [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)
- C. M. Jackman
- Space and Atmospheric Physics, Blackett Laboratory; Imperial College London; London UK
| | - R. J. Forsyth
- Space and Atmospheric Physics, Blackett Laboratory; Imperial College London; London UK
| | - M. K. Dougherty
- Space and Atmospheric Physics, Blackett Laboratory; Imperial College London; London UK
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Hill TW, Thomsen MF, Henderson MG, Tokar RL, Coates AJ, McAndrews HJ, Lewis GR, Mitchell DG, Jackman CM, Russell CT, Dougherty MK, Crary FJ, Young DT. Plasmoids in Saturn's magnetotail. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007ja012626] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [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)
- T. W. Hill
- Physics and Astronomy Department; Rice University; Houston Texas USA
| | - M. F. Thomsen
- Los Alamos National Laboratory; Los Alamos New Mexico USA
| | | | - R. L. Tokar
- Los Alamos National Laboratory; Los Alamos New Mexico USA
| | - A. J. Coates
- Mullard Space Science Laboratory; University College London; Surrey UK
| | | | - G. R. Lewis
- Mullard Space Science Laboratory; University College London; Surrey UK
| | - D. G. Mitchell
- Johns Hopkins University; Applied Physics Laboratory; Laurel Maryland USA
| | | | - C. T. Russell
- Institute of Geophysics; University of California; Los Angeles California USA
| | | | - F. J. Crary
- Space Science and Engineering; Southwest Research Institute; San Antonio Texas USA
| | - D. T. Young
- Space Science and Engineering; Southwest Research Institute; San Antonio Texas USA
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Jackman CM. Interplanetary conditions and magnetospheric dynamics during the Cassini orbit insertion fly-through of Saturn's magnetosphere. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2005ja011054] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [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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27
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Jackman CM. Interplanetary magnetic field at ∼9 AU during the declining phase of the solar cycle and its implications for Saturn's magnetospheric dynamics. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2004ja010614] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.2] [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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