68 results on '"Christopher Cully"'
Search Results
2. Modelling the Response of Riometers to Medium Energy Electron Precipitation
- Author
-
Reihaneh Ghaffari, Christopher Cully, Robert Gillies, Emma Spanswick, and Daniel Marsh
- Abstract
Precipitating energetic particles can penetrate into the low-altitude ionosphere and alter the ionization rate. Enhanced ionization in the D-region caused by energetic particle precipitation (EPP) affects cosmic radio signal absorption in the ionosphere. This impact is monitored by a Canadian network of wide-beam passive radio receivers, or riometers, to study precipitation-induced variations in the D-region ionosphere remotely. In this study, we examine the relationship between the background ionospheric profiles and absorption during a precipitation event observed by one of the POES satellites in conjunction with the Gillam riometer station (56N, 95W). We use different chemistry models to model the D-region ionosphere and investigate the effect of changing the chemistry model in an absorption event. We compare modelled absorption with ground-based measurements to discuss possible reasons for any discrepancy.
- Published
- 2023
3. The AEPEX mission: Imaging energetic particle precipitation in the atmosphere through its bremsstrahlung X-ray signatures
- Author
-
Alexandra Wold, Allison Jaynes, Robert A. Marshall, Michael McCarthy, Thomas N. Woods, Cora E. Randall, Grant D. Berland, Wei Xu, Christopher Cully, Daniel N. Baker, Harlan E. Spence, and Elliott Davis
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,Astrophysics::High Energy Astrophysical Phenomena ,Aerospace Engineering ,Electron precipitation ,Flux ,01 natural sciences ,Atmosphere ,symbols.namesake ,0103 physical sciences ,010303 astronomy & astrophysics ,Image resolution ,Physics::Atmospheric and Oceanic Physics ,0105 earth and related environmental sciences ,Remote sensing ,Range (particle radiation) ,Spacecraft ,business.industry ,Bremsstrahlung ,Astronomy and Astrophysics ,Geophysics ,Space and Planetary Science ,Van Allen radiation belt ,Physics::Space Physics ,symbols ,General Earth and Planetary Sciences ,Environmental science ,Astrophysics::Earth and Planetary Astrophysics ,business - Abstract
The Atmospheric Effects of Precipitation through Energetic X-rays (AEPEX) mission is a 6U CubeSat that will monitor energetic electron precipitation from the radiation belts into the upper atmosphere. The primary instrument will image energetic (50–300 keV) X-rays produced in the atmosphere by bremsstrahlung, providing a near-direct signature of electron precipitation. An energetic electron detector will measure the precipitating electron spectrum, while the X-ray observations will be used to determine the absolute flux. X-ray images will be produced with 10-s time resolution and 50–100 km spatial resolution. The 6U spacecraft uses flight heritage spacecraft bus subsystems, including the attitude determination and control, electrical power, and command & data handling systems. AEPEX is designed to be operated from low-Earth orbit at ~ 500 km altitude with a high inclination in order to cover the outer radiation belt. AEPEX will be the first spacecraft mission to measure X-rays in the 50–300 keV energy range emitted by Earth’s atmosphere in response to radiation belt precipitation, and the first to image that precipitation from above.
- Published
- 2020
4. Conjugate observation of magnetospheric chorus propagating to the ionosphere by ducting
- Author
-
Yangyang Shen, A. D. Howarth, Anton Artemyev, Martin Connors, S. Tian, Xiao-Jia Zhang, Michael Hartinger, Richard B. Horne, Lunjin Chen, Jiashu Wu, H. Gordon James, Vassilis Angelopoulos, Christopher Cully, Jacob Bortnik, and Andrew W. Yau
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,biology ,Wave propagation ,Chorus ,Magnetosphere ,Geophysics ,biology.organism_classification ,01 natural sciences ,7. Clean energy ,Physics::Geophysics ,13. Climate action ,0103 physical sciences ,Physics::Space Physics ,General Earth and Planetary Sciences ,Atmospheric duct ,Ionosphere ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Conjugate - Abstract
Whistler-mode chorus waves are critical for driving resonant scattering and loss of radiation belt relativistic electrons into the atmosphere. The resonant energies of electrons scattered by chorus waves increase at increasingly higher magnetic latitudes. Propagation of chorus waves to middle and high latitudes is hampered by wave divergence and Landau damping but is promoted otherwise if ducted by density irregularities. Although ducting theories have been proposed since the 1960’s, no conjugate observation of ducted chorus propagation from the equatorial magnetosphere to the ionosphere has been observed so far. Here we provide such an observation, for the first time, using conjugate spacecraft measurements. Ducted chorus waves maintain significant wave power upon reaching the ionosphere, which is confirmed by ray tracing simulations. Our results suggest that ducted chorus waves may be an important driver for relativistic electron precipitation.
- Published
- 2021
5. The Solar Orbiter Radio and Plasma Waves (RPW) instrument (Corrigendum)
- Author
-
Andris Vaivads, V. Krupař, M. Chariet, Lars Bylander, L. R. Malac-Allain, J. Parisot, Mats André, W. Recart, W. Puccio, C. Agrapart, D. Bérard, V. Leray, Robert F. Wimmer-Schweingruber, K. Boughedada, Baptiste Cecconi, E. Lorfèvre, M. Steller, B. Katra, F. Chapron, Helmut O. Rucker, Stuart D. Bale, Matthieu Kretzschmar, J.-C. Pellion, Ivana Kolmasova, J. Sanisidro, N. Quéruel, Filippo Pantellini, V. Bouzid, Laurent Lamy, Milan Maksimovic, L. Guéguen, C. Fiachetti, S. Chaintreuil, Mykhaylo Panchenko, Karine Issautier, M. Dekkali, O. Krupařová, Keith Goetz, Tomas Karlsson, I. Fratter, H. Ottacher, Philippe Louarn, P. Fergeau, O. Le Contel, Christopher J. Owen, Jan Soucek, A. Retino, Mihailo M. Martinović, Y. de Conchy, Olga Alexandrova, E. Bellouard, G. T. Delory, David Pisa, S. Thijs, E. Guilhem, Anders Eriksson, L. Åhlén, Antonio Vecchio, Timothy S. Horbury, Ondrej Santolik, Eduard P. Kontar, T. Vincent, V. Cripps, Daniel Dias, I. Zouganelis, A. Jeandet, T. Dudok de Wit, Sonny Lion, L. Uhlíř, Quynh Nhu Nguyen, M. Timofeeva, Dirk Plettemeier, J. Baše, Christopher Cully, Petr Hellinger, Lorenzo Matteini, Fouad Sahraoui, C. Collin, Paul Turin, Javier Rodriguez-Pacheco, Säm Krucker, P. Plasson, J.-Y. Brochot, Vladimir Krasnoselskikh, P. Leroy, Petr Travnicek, R. Lán, Yu. V. Khotyaintsev, S.-E. Jansson, Štěpán Štverák, G. Barbary, Pierre Astier, G. Jannet, R. Piberne, E. P. G. Johansson, F. Gonzalez, P. Danto, Arnaud Zaslavsky, J. Břínek, Thomas Chust, Xavier Bonnin, C. Laffaye, G. Cassam-Chenai, S. Julien, B. Pontet, Matthieu Berthomier, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Swedish Institute of Space Physics [Uppsala] (IRF), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Commission for Astronomy of the Austrian Academy of Sciences, Austrian Academy of Sciences (OeAW), Institute of Atmospheric Physics [Prague] (IAP), Czech Academy of Sciences [Prague] (CAS), Space Research Institute of Austrian Academy of Sciences (IWF), Royal Institute of Technology [Stockholm] (KTH ), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Nexeya Conseil & Formation, Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud university [Nijmegen], Centre National d'Études Spatiales [Toulouse] (CNES), Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Université Paul-Valéry - Montpellier 3 (UPVM)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), ALTRAN (FRANCE), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES), Univerzita Karlova v Praze, Universities Space Research Association (USRA), NASA Goddard Space Flight Center (GSFC), Department of Physics and Astronomy [Calgary], University of Calgary, School of Physics and Astronomy [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Department of Physics [Imperial College London], Imperial College London, University of Glasgow, Fachhochschule Nordwestschweiz [Windisch] (FHNW), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, University of Belgrade [Belgrade], Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Universidad de Alcalá - University of Alcalá (UAH), Institute of Experimental and Applied Physics [Kiel] (IEAP), Christian-Albrechts-Universität zu Kiel (CAU), European Space Astronomy Centre (ESAC), European Space Agency (ESA), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Radboud University [Nijmegen], Université Paul-Valéry - Montpellier 3 (UPVM)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Université de Rennes (UR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Agence Spatiale Européenne = European Space Agency (ESA)
- Subjects
Physics ,010308 nuclear & particles physics ,Astronomy ,Astronomy and Astrophysics ,Astrophysics ,Plasma ,01 natural sciences ,law.invention ,instrumentation: miscellaneous ,Solar wind ,Orbiter ,solar wind ,Space and Planetary Science ,law ,0103 physical sciences ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,010303 astronomy & astrophysics ,addenda ,ComputingMilieux_MISCELLANEOUS ,errata - Abstract
Contains fulltext : 239392.pdf (Publisher’s version ) (Open Access)
- Published
- 2021
6. The Vertical Distribution of the Optical Emissions of a Steve and Picket Fence Event
- Author
-
R. Downie, J. Smith, Gareth Perry, D. Eurich, W. E. Archer, B. Gallardo-Lacourt, Eric Donovan, D. M. Gillies, Christopher Cully, and J.-P. St.-Maurice
- Subjects
Geophysics ,Meteorology ,Via fence ,General Earth and Planetary Sciences ,Event (particle physics) ,Geology - Published
- 2019
7. Statistical Study of Whistler-Mode Waves and Expected Pitch Angle Diffusion Rates During Dispersionless Electron Injections
- Author
-
Christine Gabrielse, R. Ghaffari, and Christopher Cully
- Subjects
Physics ,Geophysics ,010504 meteorology & atmospheric sciences ,0103 physical sciences ,General Earth and Planetary Sciences ,Electron ,Pitch angle ,Diffusion (business) ,Whistler mode ,010303 astronomy & astrophysics ,01 natural sciences ,0105 earth and related environmental sciences ,Computational physics - Abstract
Energetic electron injections can generate or amplify electromagnetic waves such as whistler-mode waves. These waves can resonantly interact with available particles to affect their equatorial pitch angle. This process can be considered as a diffusion that scatters particles into the loss cone. This study investigates whistler-mode wave generation in conjunction with electron injections using in situ wave measurements by the Time History of Events and Macroscale Interactions during Substorms mission during 2011-2020. We characterize the whistler-mode wave behavior associated with 733 selected dispersionless electron injections and dipolarizing flux bundles (DFBs). We observe intense wave activity and strong diffusion associated with only the top 5% and 10% of the selected injection events, respectively. We also study the wave activity when there is a sharp rise in the northward component of the magnetic field around the injection time (DFBs). In this case, the generated wave powers increase, and the power change is at least two times greater than non-DFB injections.
- Published
- 2021
8. Driving of Outer Belt Electron Loss by Solar Wind Dynamic Pressure Structures : Analysis of Balloon and Satellite Data
- Author
-
Qianli Ma, Christopher Cully, Xiao-Jia Zhang, Aaron Breneman, L. A. Woodger, Alexa Halford, J. K. Sandhu, Kyle R. Murphy, S. S. Elliott, Thiago Brito, Robyn Millan, Wen Li, L. Capannolo, and Department of Physics
- Subjects
010504 meteorology & atmospheric sciences ,F300 ,Barrel (horology) ,Balloon ,Atmospheric sciences ,01 natural sciences ,Satellite data ,MAGNETOSPHERE ,0103 physical sciences ,SCATTERING ,Precipitation ,MODE ,MODULATION ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Physics ,MAGNETOSONIC WAVES ,DRIVEN ,115 Astronomy, Space science ,Electron loss ,VAN ALLEN PROBES ,Solar wind ,Geophysics ,13. Climate action ,Space and Planetary Science ,PRECIPITATION ,Physics::Space Physics ,Dynamic pressure ,Astrophysics::Earth and Planetary Astrophysics ,FREQUENCY WAVES ,ULF WAVES - Abstract
We present observations of similar to 10-60 min solar wind dynamic pressure structures that drive large-scale coherent similar to 20-100 keV electron loss from the outer radiation belt. A combination of simultaneous satellite and Balloon Array for Radiation-belt Relativistic Electron Losses (BARREL) observations on 11-12 January 2014 shows a close association between the pressure structures and precipitation as inferred from BARREL X-rays. Specifically, the structures drive radial ExB transport of electrons up to 1 Earth radii, modulating the free electron energy available for low-frequency plasmaspheric hiss growth, and subsequent hiss-induced loss cone scattering. The dynamic pressure structures, originating near the Sun and commonly observed advecting with the solar wind, are thus able to switch on scattering loss of electrons by hiss over a large spatial scale. Our results provide a direct link between solar wind pressure fluctuations and modulation of electron loss from the outer radiation belt and may explain long-period modulations and large-scale coherence of X-rays commonly observed in the BARREL data set. Plain Language Summary The Earth's low-density magnetosphere is a region of enclosed magnetic field lines that contains energetic electrons ranging from eV to MeV energies. These populations can be greatly enhanced in response to solar driving. Following enhancements, energetic electron populations are depleted on timescales of hours to days by various processes. One important depletion process occurs when an electromagnetic plasma wave called plasmaspheric hiss, which exists within a high plasma density region called the plasmasphere and its (occasional) radial extension called the plume, scatters energetic electrons into the atmosphere. In this paper, we show that these hiss waves can be switched on by compressions of the magnetosphere which occur in response to similar to 1 hr long pressure structures in the solar wind. These structures originate at or near the Sun and are very common in the solar wind at 1 AU. The newly excited hiss waves scatter electrons into the atmosphere where they are observed on balloon-borne X-ray detectors. Our results suggest that magnetospheric models that predict the loss of electrons from hiss waves may be improved by consideration of solar wind pressure-driven dynamics.
- Published
- 2020
9. Characteristics of Electron Precipitation During 40 Energetic Electron Injections Inferred via Subionospheric VLF Signal Propagation
- Author
-
Christopher Cully, Geoffrey D. Reeves, R. Ghaffari, and Drew Turner
- Subjects
Physics ,Radio propagation ,Geophysics ,010504 meteorology & atmospheric sciences ,Space and Planetary Science ,0103 physical sciences ,Electron precipitation ,Electron ,010303 astronomy & astrophysics ,01 natural sciences ,Molecular physics ,0105 earth and related environmental sciences - Published
- 2020
10. The Solar Orbiter Radio and Plasma Waves (RPW) instrument
- Author
-
L. R. Malac-Allain, T. Dudok de Wit, E. Lorfèvre, C. Collin, J. Sanisidro, Mihailo M. Martinović, X. Bonnin, E. Guilhem, Milan Maksimovic, P. Leroy, A. Vecchio, Eduard P. Kontar, L. Uhlíř, N. Quéruel, H. Ottacher, K. Boughedada, Christopher Cully, G. Barbary, Pierre Astier, Anders Eriksson, L. Åhlén, O. Krupařová, B. Pontet, T. Chust, G. Jannet, J. Parisot, Mats André, Paul Turin, P. Plasson, F. Chapron, M. Steller, W. Recart, W. Puccio, Vladimir Krasnoselskikh, Robert F. Wimmer-Schweingruber, V. Bouzid, Laurent Lamy, V. Cripps, R. Lán, Keith Goetz, B. Katra, S. Chaintreuil, Gregory T. Delory, I. Fratter, Dirk Plettemeier, C. Fiachetti, V. Krupař, M. Chariet, Sonny Lion, M. Dekkali, Lars Bylander, F. Gonzalez, Jan Soucek, Christopher J. Owen, Mykhaylo Panchenko, P. Danto, David Pisa, T. Vincent, Y. de Conchy, Säm Krucker, G. Cassam-Chenai, S. Julien, Baptiste Cecconi, Olga Alexandrova, A. Retino, V. Leray, Karine Issautier, S. Thijs, E. P. G. Johansson, Filippo Pantellini, D. Bérard, J. Baše, L. Guéguen, R. Piberne, P. Fergeau, Matthieu Berthomier, Tomas Karlsson, Arnaud Zaslavsky, Quynh Nhu Nguyen, J.-Y. Brochot, E. Bellouard, Yu. V. Khotyaintsev, Lorenzo Matteini, Štěpán Štverák, Javier Rodriguez-Pacheco, Fouad Sahraoui, S.-E. Jansson, O. Le Contel, Timothy S. Horbury, J.-C. Pellion, Pavel M. Trávníček, A. Jeandet, C. Agrapart, Petr Hellinger, Ondrej Santolik, I. Zouganelis, C. Laffaye, M. Timofeeva, D. Dias, Philippe Louarn, Helmut O. Rucker, Stuart D. Bale, Ivana Kolmasova, J. Břínek, Matthieu Kretzschmar, Andris Vaivads, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Swedish Institute of Space Physics [Uppsala] (IRF), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Institute of Computing [Campinas] (IC), Universidade Estadual de Campinas = University of Campinas (UNICAMP), Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Centre d'Investigation Clinique [CHU Clermont-Ferrand] (CIC 1405), Institut National de la Santé et de la Recherche Médicale (INSERM)-Direction de la recherche clinique et de l’innovation [CHU Clermont-Ferrand] (DRCI), CHU Clermont-Ferrand-CHU Clermont-Ferrand, Department of Physics [Imperial College London], Imperial College London, Laboratoire Structures, Propriétés et Modélisation des solides (SPMS), Institut de Chimie du CNRS (INC)-CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Hasselt University (UHasselt), Centre National d'Études Spatiales [Toulouse] (CNES), Centre National d’Etudes Spatiales, Centre National d’Études Spatiales [Paris] (CNES), Laboratoire de physique et chimie de l'environnement (LPCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), DIREN RHONE ALPES LYON FRA, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), International Agency for Research on Cancer (IARC), Institute of Genetics and Molecular Medicine, University of Edinburgh, Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Institute of Atmospheric Physics [Prague] (IAP), Czech Academy of Sciences [Prague] (CAS), NASA Goddard Space Flight Center (GSFC), Universities Space Research Association (USRA), Jiangsu University of Science and Technology (JUST), Universidade Estadual Paulista Júlio de Mesquita Filho = São Paulo State University (UNESP), Alfven Laboratory, Royal Institute of Technology [Stockholm] (KTH ), Department of Plant Physiology, Umeå University, Umea Plant Science Centre, Umeå University-Umeå University, Swedish University of Agricultural Sciences (SLU), Department of Space and Plasma Physics [Stockholm], KTH School of Electrical Engineering, Royal Institute of Technology [Stockholm] (KTH )-Royal Institute of Technology [Stockholm] (KTH ), Swedish Institute of Space Physics [Kiruna] (IRF), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institute of Computing [Campinas] (UNICAMP), Universidade Estadual de Campinas (UNICAMP), Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of California [Berkeley], University of California-University of California, Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), and European Space Agency (European Space Agency) (ESA)
- Subjects
010504 meteorology & atmospheric sciences ,Astronomy ,Astrophysics ,Plasma oscillation ,01 natural sciences ,law.invention ,Orbiter ,Astronomi, astrofysik och kosmologi ,law ,0103 physical sciences ,Astronomy, Astrophysics and Cosmology ,Aerospace engineering ,010303 astronomy & astrophysics ,miscellaneous [instrumentation] ,0105 earth and related environmental sciences ,Physics ,business.industry ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy and Astrophysics ,Plasma ,Solar radio ,instrumentation: miscellaneous ,Solar wind ,solar wind ,Space and Planetary Science ,Physics::Space Physics ,Astrophysics::Earth and Planetary Astrophysics ,Interplanetary spaceflight ,business ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] - Abstract
The Radio and Plasma Waves (RPW) instrument on the ESA Solar Orbiter mission is described in this paper. This instrument is designed to measure in-situ magnetic and electric fields and waves from the continuous to a few hundreds of kHz. RPW will also observe solar radio emissions up to 16 MHz. The RPW instrument is of primary importance to the Solar Orbiter mission and science requirements since it is essential to answer three of the four mission overarching science objectives. In addition RPW will exchange on-board data with the other in-situ instruments in order to process algorithms for interplanetary shocks and type III langmuir waves detections. Correction in: Astronomy & Astrophysics, Volume 654, Article Number C2, DOI 10.1051/0004-6361/201936214e
- Published
- 2020
11. Observation of High‐Energy Electrons Precipitated by NWC Transmitter From PROBA‐V Low‐Earth Orbit Satellite
- Author
-
E. Botek, Gregory S. Cunningham, Jean-Francois Ripoll, Christopher Cully, and Viviane Pierrard
- Subjects
Physics ,education.field_of_study ,Astrophysics::High Energy Astrophysical Phenomena ,Population ,Resonance ,Electron ,Computational physics ,Magnetic field ,law.invention ,Telescope ,Geophysics ,Flux (metallurgy) ,law ,General Earth and Planetary Sciences ,Particle ,Satellite ,education - Abstract
The very low‐frequency transmitter in the Northwest Cape of Australia (NWC) has previously been observed to pitch‐angle scatter electrons with energies from 30–400 keV, creating enhanced fluxes measured by low‐Earth orbiting (LEO) satellites. Here we use observations from the Energetic Particle Telescope on PROBA‐V. We compare the measured flux, as a function of local magnetic field strength, when the NWC transmitter is “on” versus “off,” and find enhanced fluxes only when NWC is “on” and located on the nightside. The enhanced fluxes occur in the population gradually transitioning from “permanently trapped” to “quasi‐trapped.” We show that electrons up to 800 keV, substantially higher energy than previously studied, are scattered by resonant interactions with NWC to produce enhanced fluxes. The enhanced fluxes appear at multiple L‐shells for each energy channel, consistent with resonance conditions at distinct wave normal angles, that indicate ducted interactions at L 1.65.
- Published
- 2020
12. Statistical Study of Pitch Angle Diffusion during Substorm Injections
- Author
-
Reihaneh Ghaffari and Christopher Cully
- Subjects
Materials science ,Physics::Space Physics ,Substorm ,Pitch angle ,Diffusion (business) ,Computational physics - Abstract
Energetic Electron Precipitation (EEP) associated with substorm injections typically occurs when magnetospheric waves, particularly whistler-mode waves, resonantly interact with electrons to affect their equatorial pitch angle. This can be considered as a diffusion process that scatters particles into the loss cone. In this study, we investigate whistler-mode wave generation in conjunction with electron injections using in-situ wave measurements by the Themis mission. We calculate the pitch angle diffusion coefficient exerted by the observed wave activity using the quasi-linear diffusion approximation and estimate scattering efficiency in the substorm injection region to constrain where and how much scattering happens typically during these events.
- Published
- 2020
13. Atmospheric effects and signatures of high-energy electron precipitation
- Author
-
Christopher Cully and Robert A. Marshall
- Subjects
Electron density ,Monte Carlo method ,Bremsstrahlung ,Electron precipitation ,law.invention ,Computational physics ,symbols.namesake ,law ,Ionization ,Van Allen radiation belt ,Riometer ,symbols ,Radar ,Physics::Atmospheric and Oceanic Physics - Abstract
Precipitation in the upper atmosphere of energetic radiation belt electrons leads to a number of secondary effects, including the production of new ionization, emission of X-rays via bremsstrahlung, optical emissions, and chemical changes. In this chapter, we describe these effects and the physics behind them. We then discuss modeling techniques to calculate these effects, including scaling and Monte Carlo techniques. We next describe the diagnostic techniques used to detect atmospheric effects of precipitation; these include space-based and balloon-based particle and X-ray measurements, ground-based optical detection, and ground-based radar, riometer, and subionospheric very-low-frequency (VLF) remote sensing of the D-region electron density disturbance. Finally, we describe future experiments and observations that will help to improve quantification of energetic precipitation fluxes and spectra.
- Published
- 2020
14. The Space Physics Environment Data Analysis System (SPEDAS)
- Author
-
Tomonori Segawa, Aaron Breneman, M. H. Liu, Matthew D. McCarthy, Kunihiro Keika, David M. Smith, R. C. Johnson, S. Matsuda, Kanako Seki, Arnaud Masson, Christopher M. Fowler, Drew Turner, Ian J. Cohen, Atsuki Shinbori, Jasper Halekas, Robert E. Ergun, E. Lucas, Alexa Halford, Brian Walsh, Allison Jaynes, Eric Grimes, Marc Pulupa, Jeremy Faden, D. A. King, David L. Mitchell, P. Cruce, Sunny W. Y. Tam, Eric Donovan, R. E. McGuire, Joseph Westlake, James L. Burch, A. DeWolfe, Yuki Harada, U. Auster, James W. Lewis, Matthew R. Argall, Ferdinand Plaschke, Yoichi Kazama, Ayako Matsuoka, Phyllis Whittlesey, Alexander Drozdov, Roberto Livi, Robyn Millan, Michael Galloy, Mariko Teramoto, C. L. Russell, Frederick Wilder, Haje Korth, Juan V. Rodriguez, A. A. Narock, Norio Umemura, Atsushi Kumamoto, Kenneth R. Bromund, Christopher Cully, C. Y. Chiang, P. Robert, T. F. Chang, L. A. Woodger, Yoshizumi Miyoshi, J. P. McFadden, A. Keiling, L. Andersson, Davin Larson, I. Shinohara, B. J. Wang, Christina O. Lee, Masafumi Shoji, P. Dunn, T. D. Phan, T. Kovalick, Stuart D. Bale, John Sample, Kris Kersten, S. UeNo, J. M. McTiernan, S. Abe, P. Schroeder, Takuya Hara, Tomoaki Hori, Jon Vandegriff, Harald U. Frey, Robert J. Redmon, Yoshiya Kasahara, Robert Lillis, Masahito Nose, Robert M. Candey, Yukitoshi Nishimura, Howard J. Singer, James M. Weygand, Vassilis Angelopoulos, Mitsuo Oka, O. Le Contel, Shiang-Yu Wang, Brian Jackel, Yoshimasa Tanaka, Kazushi Asamura, Yukinaga Miyashita, John W. Bonnell, Bryan Harter, D. A. Roberts, N. Hatzigeorgiu, Barbara L. Giles, Laboratoire de Physique des Plasmas (LPP), Université Paris-Saclay-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-École polytechnique (X)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
- Subjects
010504 meteorology & atmospheric sciences ,Solar wind ,Ionospheric physics ,Planetary magnetospheres ,ASCII ,01 natural sciences ,Article ,Space exploration ,Software ,Heliophysics ,Data retrieval ,[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,0103 physical sciences ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,computer.programming_language ,Graphical user interface ,Geospace science ,business.industry ,Software development ,Astronomy and Astrophysics ,Python (programming language) ,Space and Planetary Science ,Magnetospheric physics ,Space plasmas ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Software engineering ,business ,computer - Abstract
著者人数: 102名(所属. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS): 松岡, 彩子; 篠原, 育; 浅村, 和史), Accepted: 2018-12-29, 資料番号: SA1180350000
- Published
- 2019
15. Converting Riometer Absorptions to Electron Energy Fluxes Based on the First Principle Modeling of Ionospheric Responses to Energetic Electrons, X-Rays and Solar Protons Precipitations
- Author
-
Alexei Kouznetsov, Christopher Cully, and Emma Spanswick
- Published
- 2019
16. Empirical estimates and theoretical predictions of the shorting factor for the THEMIS double-probe electric field instrument
- Author
-
S. Califf and Christopher Cully
- Subjects
Physics ,Geophysics ,Nuclear magnetic resonance ,010504 meteorology & atmospheric sciences ,Space and Planetary Science ,Electric field ,Double probe ,0103 physical sciences ,01 natural sciences ,010305 fluids & plasmas ,0105 earth and related environmental sciences ,Computational physics - Published
- 2016
17. Global observations of substorm injection region evolution: 27 August 2001
- Author
-
J. B. Blake, Eric Donovan, Brian Jackel, Allan T. Weatherwax, Jun Liang, Geoffrey D. Reeves, R. H. W. Friedel, Emma Spanswick, W. W. Liu, and Christopher Cully
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,01 natural sciences ,010305 fluids & plasmas ,Electron injection ,0103 physical sciences ,Riometer ,Substorm ,Earth and Planetary Sciences (miscellaneous) ,lcsh:Science ,0105 earth and related environmental sciences ,Physics ,Spacecraft ,business.industry ,lcsh:QC801-809 ,Geosynchronous orbit ,Geology ,Astronomy and Astrophysics ,Geophysics ,lcsh:QC1-999 ,lcsh:Geophysics. Cosmic physics ,Orbit ,Space and Planetary Science ,lcsh:Q ,Ionosphere ,National laboratory ,business ,lcsh:Physics - Abstract
We present riometer and in situ observations of a substorm electron injection on 27 August 2001. The event is seen at more than 20 separate locations (including ground stations and 6 satellites: Cluster, Polar, Chandra, and 3 Los Alamos National Laboratory (LANL) spacecraft). The injection is observed to be dispersionless at 12 of these locations. Combining these observations with information from the GOES-8 geosynchronous satellite we argue that the injection initiated near geosynchronous orbit and expanded poleward (tailward) and equatorward (earthward) afterward. Further, the injection began several minutes after the reconnection identified in the Cluster data, thus providing concrete evidence that, in at least some events, near-Earth reconnection has little if any ionospheric signature.
- Published
- 2018
18. Computational Model of D-Region Ion Production Caused by Energetic Electron Precipitations Based on General Monte Carlo Transport Calculations
- Author
-
Alexei Kouznetsov and Christopher Cully
- Published
- 2018
19. Kinship
- Author
-
Janelle Brady and Christopher Cully
- Published
- 2017
20. Correlated Pc4–5 ULF waves, whistler‐mode chorus, and pulsating aurora observed by the Van Allen Probes and ground‐based systems
- Author
-
J. B. Blake, David M. Malaspina, Harlan E. Spence, Kazue Takahashi, Christopher Cully, Daniel N. Baker, John R. Wygant, Marc Lessard, Eric Donovan, Allison Jaynes, A. Ali, Robert Michell, Emma Spanswick, Craig Kletzing, Marilia Samara, and Geoffrey D. Reeves
- Subjects
Physics ,biology ,Field line ,Scattering ,Chorus ,Magnetosphere ,Geophysics ,Astrophysics ,biology.organism_classification ,Physics::Geophysics ,Space and Planetary Science ,Auroral chorus ,Physics::Space Physics ,Substorm ,Astrophysics::Solar and Stellar Astrophysics ,Van Allen Probes ,Pitch angle - Abstract
Theory and observations have linked equatorial VLF waves with pulsating aurora for decades, invoking the process of pitch angle scattering of tens of keV electrons in the equatorial magnetosphere. Recently published satellite studies have strengthened this argument, by showing strong correlation between pulsating auroral patches and both lower-band chorus and tens of keV electron modulation in the vicinity of geosynchronous orbit. Additionally, a previous link has been made between Pc4–5 compressional pulsations and modulation of whistler-mode chorus using Time History of Events and Macroscale Interactions during Substorms. In the current study, we present simultaneous in situ observations of structured chorus waves and an apparent field line resonance (in the Pc4–5 range) as a result of a substorm injection, observed by Van Allen Probes, along with ground-based observations of pulsating aurora. We demonstrate the likely scenario being one of substorm-driven Pc4–5 ULF pulsations modulating chorus waves, and thus providing the driver for pulsating particle precipitation into the Earth's atmosphere. Interestingly, the modulated chorus wave and ULF wave periods are well correlated, with chorus occurring at half the periodicity of the ULF waves. We also show, for the first time, a particular few-Hz modulation of individual chorus elements that coincides with themore » same modulation in a nearby pulsating aurora patch. As a result, such modulation has been noticed as a high-frequency component in ground-based camera data of pulsating aurora for decades and may be a result of nonlinear chorus wave interactions in the equatorial region.« less
- Published
- 2015
21. Whistler-mode waves inside flux pileup region: Structured or unstructured?
- Author
-
Huishan Fu, Shiyong Huang, Eva Macusova, Andris Vaivads, Haoyu Lu, Yuri V. Khotyaintsev, Qiugang Zong, Christopher Cully, Jinbin Cao, Meng Zhou, Ondrej Santolik, Vassilis Angelopoulos, Mats André, Zeren Zhima, and Wenlong Liu
- Subjects
Physics ,Jet (fluid) ,Whistler ,Flux ,Geophysics ,Physics::Geophysics ,Computational physics ,Magnetic field ,Dipole ,Amplitude ,Earth's magnetic field ,Space and Planetary Science ,Physics::Space Physics ,Outflow - Abstract
During reconnection, a flux pileup region (FPR) is formed behind a dipolarization front in an outflow jet. Inside the FPR, the magnetic field magnitude and Bz component increase and the whistler-mode waves are observed frequently. As the FPR convects toward the Earth during substorms, it is obstructed by the dipolar geomagnetic field to form a near-Earth FPR. Unlike the structureless emissions inside the tail FPR, we find that the whistler-mode waves inside the near-Earth FPR can exhibit a discrete structure similar to chorus. Both upper band and lower band chorus are observed, with the upper band having a larger propagation angle (and smaller wave amplitude) than the lower band. Most chorus elements we observed are “rising-tone” type, but some are “falling-tone” type. We notice that the rising-tone chorus can evolve into falling-tone chorus within
- Published
- 2014
22. Quantified energy dissipation rates in the terrestrial bow shock: 2. Waves and dissipation
- Author
-
David G. Sibeck, O. Le Contel, Aaron Breneman, Drew Turner, David M. Malaspina, Christopher Cully, Vassilis Angelopoulos, and Lynn B. Wilson
- Subjects
Physics ,Shock wave ,Spacecraft ,Whistler ,business.industry ,Astrophysics::High Energy Astrophysical Phenomena ,Mechanics ,Dissipation ,Nonlinear system ,Geophysics ,Classical mechanics ,Magnetosheath ,Amplitude ,13. Climate action ,Space and Planetary Science ,Bow wave ,Physics::Space Physics ,business - Abstract
We present the first quantified measure of the energy dissipation rates, due to wave-particle interactions, in the transition region of the Earth's collisionless bow shock using data from the Time History of Events and Macroscale Interactions during Substorms spacecraft. Our results show that wave-particle interactions can regulate the global structure and dominate the energy dissipation of collisionless shocks. In every bow shock crossing examined, we observed both low-frequency ( 9000 Ω m; and (4) associated energy dissipation rates >10 μW m−3. The dissipation rates due to wave-particle interactions exceeded rates necessary to explain the increase in entropy across the shock ramps for ∼90% of the wave burst durations. For ∼22% of these times, the wave-particle interactions needed to only be ≤ 0.1% efficient to balance the nonlinear wave steepening that produced the shock waves. These results show that wave-particle interactions have the capacity to regulate the global structure and dominate the energy dissipation of collisionless shocks.
- Published
- 2014
23. Plasma particle simulations of wake formation behind a spacecraft with thin wire booms
- Author
-
Christopher Cully, Yohei Miyake, Hideyuki Usui, and Hiroshi Nakashima
- Subjects
Physics ,Spacecraft ,business.industry ,Plasma ,Wake ,Boom ,Computational physics ,symbols.namesake ,Geophysics ,Optics ,Amplitude ,Physics::Plasma Physics ,Space and Planetary Science ,Electric field ,Physics::Space Physics ,symbols ,Satellite ,business ,Debye - Abstract
[1] Double-probe electric field sensors installed on scientific spacecraft are often deployed using wire booms with radii much less than typical Debye lengths of magnetospheric plasmas (millimeters compared to tens of meters). However, in tenuous and cold-streaming plasmas seen in the polar cap and lobe regions, the wire booms, electrically grounded at the spacecraft, have a high positive potential due to photoelectron emission and can strongly scatter approaching ions. Consequently, an electrostatic wake formed behind the spacecraft is further enhanced by the presence of the wire booms. We reproduce this process for the case of the Cluster satellite by performing plasma particle-in-cell (PIC) simulations, which include the effects of both the spacecraft body and the wire booms in a simultaneous manner. The simulations reveal that the effective thickness of the booms for the Cluster Electric Field and Wave (EFW) instrument is magnified from its real diameter (2.2mm) to several meters, when the spacecraft potential is at tens of volts. Such booms enhance the wake electric field magnitude by a factor of 1.5–2 depending on the spacecraft potential and play a principal role in explaining the in situ Cluster EFW data showing sinusoidal spurious electric fields with about 10mV/m amplitude. The boom effects are quantified by comparing PIC simulations with and without wire booms and also by examining the wake formation for various spacecraft potentials.
- Published
- 2013
24. Future Atmosphere-Ionosphere-Magnetosphere Coupling Study Requirements
- Author
-
Larry Kepko, Christopher Cully, Thomas E. Moore, Eric Donovan, Jeffrey P. Thayer, Douglas E. Rowland, Gregory Earle, Rod Heelis, Glyn Collinson, Marc Lessard, Kevin S. Brenneman, J. H. Clemmons, Joshua Semeter, Craig J. Pollock, L. M. Kistler, George V. Khazanov, Michael J. Nicolls, C. R. Chappell, Ennio R. Sanchez, Daniel J. Gershman, Robert F. Pfaff, Robert W. Schunk, David J. Knudsen, Elizabeth MacDonald, and Robert J. Strangeway
- Subjects
Atmosphere ,Physics ,Coupling (physics) ,010504 meteorology & atmospheric sciences ,Magnetosphere ,Interplanetary magnetic field ,Ionosphere ,010502 geochemistry & geophysics ,01 natural sciences ,0105 earth and related environmental sciences ,Computational physics - Published
- 2016
25. Turbulence Heating ObserveR - satellite mission proposal
- Author
-
Andris Vaivads, Rumi Nakamura, Francesco Valentini, David Burgess, Thomas E. Moore, Zdenek Nemecek, Hantao Ji, J. L. Pinçon, Mats André, Luca Sorriso-Valvo, Rami Vainio, Damiano Caprioli, Homa Karimabadi, E. Clacey, P. Rathsman, Jonathan Eastwood, Stefan Eriksson, M. L. Goldstein, Michael A. Balikhin, Robert F. Wimmer-Schweingruber, Masahiro Hoshino, William H. Matthaeus, Benoit Lavraud, Stuart D. Bale, Denise Perrone, Christopher H. K. Chen, Yasuhito Narita, J. Soucek, Hanna Rothkaehl, J. De Keyser, Minna Palmroth, Harald Kucharek, A. N. Fazakerley, Fouad Sahraoui, Yu. V. Khotyaintsev, Daniel B. Graham, Zoltán Vörös, Enrico Camporeale, Alessandro Retinò, C. P. Escoubet, F. Marcucci, Christopher Cully, Sergio Servidio, C. Norgren, Stein Haaland, Hermann Opgenoorth, Olga Alexandrova, Swedish Institute of Space Physics [Uppsala] (IRF), Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institute of Atmospheric Physics [Prague] (IAP), Czech Academy of Sciences [Prague] (CAS), International Prevention Research Institute (IPRI), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Department of Automatic Control and Systems Engineering, University of Sheffield [Sheffield], Astronomy Unit [London] (AU), Queen Mary University of London (QMUL), Centrum Wiskunde & Informatica (CWI), Department of Astrophysical Sciences [Princeton], Princeton University, Department of Physics [Imperial College London], Imperial College London, Department of Physics and Astronomy [Calgary], University of Calgary, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Alfven Laboratory, Royal Institute of Technology [Stockholm] (KTH ), NASA Goddard Space Flight Center (GSFC), Department of Physics and Technology [Bergen] (UiB), University of Bergen (UiB), Department of Earth and Planetary Science [Tokyo], Graduate School of Science [Tokyo], The University of Tokyo (UTokyo)-The University of Tokyo (UTokyo), Princeton Plasma Physics Laboratory (PPPL), Institute for Study of Earth, Oceans and Space, University of New Hampshire (UNH), Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, INAF-IASF/Rome, Istituto Nazionale di Astrofisica (INAF), Department of Physics and Astronomy [Newark], University of Delaware [Newark], Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Faculty of Mathematics and Physics [Praha/Prague], Charles University [Prague] (CU), Earth Observation Unit [Helsinki], Finnish Meteorological Institute (FMI), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), CNR Istituto di Nanotecnologia (NANOTEC), Consiglio Nazionale delle Ricerche [Roma] (CNR), Department of Physics and Astronomy [Turku], University of Turku, Institut für Weltraumforschung [Graz] (IWF), Osterreichische Akademie der Wissenschaften (ÖAW), Institut für Experimentelle und Angewandte Physik [Kiel] (IEAP), Christian-Albrechts-Universität zu Kiel (CAU), The University of Tokyo (UTokyo), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Agence Spatiale Européenne = European Space Agency (ESA), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), and Institut für Weltraumforschung = Space Research institute [Graz] (IWF)
- Subjects
Fluids & Plasmas ,Astrophysics::High Energy Astrophysical Phenomena ,Magnetosphere ,01 natural sciences ,7. Clean energy ,Magnetosheath ,0202 Atomic, Molecular, Nuclear, Particle And Plasma Physics ,Astronomi, astrofysik och kosmologi ,[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,Physics::Plasma Physics ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Astronomy, Astrophysics and Cosmology ,010306 general physics ,space plasma physics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Physics ,ta115 ,Turbulence ,plasma properties ,Astronomy ,plasma heating ,Space physics ,Plasma ,Condensed Matter Physics ,Interstellar medium ,Solar wind ,13. Climate action ,Physics::Space Physics ,Satellite ,Astrophysics::Earth and Planetary Astrophysics ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] - Abstract
The Universe is permeated by hot, turbulent, magnetized plasmas. Turbulent plasma is a major constituent of active galactic nuclei, supernova remnants, the intergalactic and interstellar medium, the solar corona, the solar wind and the Earth's magnetosphere, just to mention a few examples. Energy dissipation of turbulent fluctuations plays a key role in plasma heating and energization, yet we still do not understand the underlying physical mechanisms involved. THOR is a mission designed to answer the questions of how turbulent plasma is heated and particles accelerated, how the dissipated energy is partitioned and how dissipation operates in different regimes of turbulence. THOR is a single-spacecraft mission with an orbit tuned to maximize data return from regions in near-Earth space - magnetosheath, shock, foreshock and pristine solar wind - featuring different kinds of turbulence. Here we summarize the THOR proposal submitted on 15 January 2015 to the 'Call for a Medium-size mission opportunity in ESAs Science Programme for a launch in 2025 (M4)'. THOR has been selected by European Space Agency (ESA) for the study phase. Funding: The THOR science team thanks the Swedish National Space Board for support to carry out a technical assessment phase study before the proposal submission. We acknowledge the useful discussion and comments from the THOR team (http://thor.irfu.se/team) and particularly D. Delcourt, D. Fontaine, A. Kis, G. Lapenta, M. Maksimovic, M. Opher, G. Paschmann, A. Petrukovic, S. Schwartz. We acknowledge: the support of the UK Space Agency through grant ST/N003322/1 to ICL; the support of Agenzia Spaziale Italiana through contract ASI-INAF 2015-039-R.O to University of Calabria, Italy and at IAPS/INAF, Rome; the support of the Belgian Science Policy Office through PRODEX PEA 4000116805 to BIRA-IASB; the support of the Czech Science Foundation through project 16-04956S to Charles University, Prague; the support of ESA PRODEX to IAP Prague; the support of CNRS and CNES to IRAP, LPP, LP2CE and LESIA; the support of the German Space Agency through grant 50 00 1603 to CAU; the support of Swedish National Space Board through grants 232/15 and 257/15 to IRF, Uppsala; the support of Academy of Finland through grant 267144 and European Research Council Consolidator through grant 682068-PRESTISSIMO to FMI; the support of ISSI team 'Kinetic Turbulence and Heating in the Solar wind'; the support of FP7 projects STORM and SHOCK. Vlasiator (http://vlasiator.fmi.fi) has been developed with the support of Academy of Finland and European Research Council Starting grant 200141-QuESpace.
- Published
- 2016
26. A mechanism for heating electrons in the magnetopause current layer and adjacent regions
- Author
-
Patrick Robert, Christopher Cully, Alain Roux, Robert E. Ergun, John W. Bonnell, O. Le Contel, Vassilis Angelopoulos, U. Auster, J. P. McFadden, Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,Meteorologi och atmosfärforskning ,Magnetosphere ,01 natural sciences ,and boundary layers ,Current sheet ,Magnetosheath ,Thermal velocity ,Astronomi, astrofysik och kosmologi ,[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,0103 physical sciences ,Earth and Planetary Sciences (miscellaneous) ,cusp ,Astronomy, Astrophysics and Cosmology ,Landau damping ,Geosciences, Multidisciplinary ,lcsh:Science ,010303 astronomy & astrophysics ,Ultra low frequency ,0105 earth and related environmental sciences ,Physics ,lcsh:QC801-809 ,Geology ,Astronomy and Astrophysics ,Geophysics ,Multidisciplinär geovetenskap ,lcsh:QC1-999 ,Computational physics ,lcsh:Geophysics. Cosmic physics ,Magnetopause ,Space and Planetary Science ,Wave-particle interactions ,Meteorology and Atmospheric Sciences ,Magnetospheric physics ,Physics::Space Physics ,Electron temperature ,Space plasma physics ,lcsh:Q ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,lcsh:Physics - Abstract
Taking advantage of the string-of-pearls configuration of the five THEMIS spacecraft during the early phase of their mission, we analyze observations taken simultaneously in the magnetosheath, the magnetopause current layer and the magnetosphere. We find that electron heating coincides with ultra low frequency waves. It seems unlikely that electrons are heated by these waves because the electron thermal velocity is much larger than the Alfvén velocity (Va). In the short transverse scale (k⊥ρi >> 1) regime, however, short scale Alfvén waves (SSAWs) have parallel phase velocities much larger than Va and are shown to interact, via Landau damping, with electrons thereby heating them. The origin of these waves is also addressed. THEMIS data give evidence for sharp spatial gradients in the magnetopause current layer where the highest amplitude waves have a large component δB perpendicular to the magnetopause and k azimuthal. We suggest that SSAWs are drift waves generated by temperature gradients in a high beta, large Ti/Te magnetopause current layer. Therefore these waves are called SSDAWs, where D stands for drift. SSDAWs have large k⊥ and therefore a large Doppler shift that can exceed their frequencies in the plasma frame. Because they have a small but finite parallel electric field and a magnetic component perpendicular to the magnetopause, they could play a key role at reconnecting magnetic field lines. The growth rate depends strongly on the scale of the gradients; it becomes very large when the scale of the electron temperature gradient gets below 400 km. Therefore SSDAW's are expected to limit the sharpness of the gradients, which might explain why Berchem and Russell (1982) found that the average magnetopause current sheet thickness to be ~400–1000 km (~500 km in the near equatorial region).
- Published
- 2011
27. Survey of cold ionospheric outflows in the magnetotail
- Author
-
Mats André, H. Vaith, Erik Engwall, Roy B. Torbert, P. A. Puhl-Quinn, Anders Eriksson, and Christopher Cully
- Subjects
Atmospheric Science ,Astrophysics::High Energy Astrophysical Phenomena ,Flux ,Magnetosphere ,Astrophysics ,Ion ,Earth and Planetary Sciences (miscellaneous) ,Astrophysics::Solar and Stellar Astrophysics ,lcsh:Science ,Physics ,Spacecraft ,business.industry ,lcsh:QC801-809 ,Geology ,Astronomy and Astrophysics ,Plasma ,Geophysics ,lcsh:QC1-999 ,lcsh:Geophysics. Cosmic physics ,Earth's magnetic field ,Space and Planetary Science ,Physics::Space Physics ,Outflow ,lcsh:Q ,Ionosphere ,business ,lcsh:Physics - Abstract
Low-energy ions escape from the ionosphere and constitute a large part of the magnetospheric content, especially in the geomagnetic tail lobes. However, they are normally invisible to spacecraft measurements, since the potential of a sunlit spacecraft in a tenuous plasma in many cases exceeds the energy-per-charge of the ions, and little is therefore known about their outflow properties far from the Earth. Here we present an extensive statistical study of cold ion outflows (0–60 eV) in the geomagnetic tail at geocentric distances from 5 to 19 RE using the Cluster spacecraft during the period from 2001 to 2005. Our results were obtained by a new method, relying on the detection of a wake behind the spacecraft. We show that the cold ions dominate in both flux and density in large regions of the magnetosphere. Most of the cold ions are found to escape from the Earth, which improves previous estimates of the global outflow. The local outflow in the magnetotail corresponds to a global outflow of the order of 1026 ions s−1. The size of the outflow depends on different solar and magnetic activity levels.
- Published
- 2009
28. Quasi-parallel whistler mode waves observed by THEMIS during near-earth dipolarizations
- Author
-
B. Ergun, Patrick Robert, Christopher C. Chaston, Christopher T. Russell, John W. Bonnell, Ian R. Mann, Christian Jacquey, Davin Larson, Benjamin Grison, Howard J. Singer, Matthieu Berthomier, Karl-Heinz Glassmeier, David G. Sibeck, Eric Donovan, O. Le Contel, Stephen B. Mende, C. W. Carlson, Alain Roux, Uli Auster, Vassilis Angelopoulos, Christopher Cully, Thomas Chust, J. P. McFadden, Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,Whistler ,Equator ,Magnetosphere ,01 natural sciences ,Current sheet ,[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,0103 physical sciences ,Substorm ,Earth and Planetary Sciences (miscellaneous) ,Magnetic pressure ,Anisotropy ,lcsh:Science ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Physics ,lcsh:QC801-809 ,Geology ,Astronomy and Astrophysics ,Geophysics ,lcsh:QC1-999 ,Computational physics ,lcsh:Geophysics. Cosmic physics ,13. Climate action ,Space and Planetary Science ,Physics::Space Physics ,Electron temperature ,lcsh:Q ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,lcsh:Physics - Abstract
We report on quasi-parallel whistler emissions detected by the near-earth satellites of the THEMIS mission before, during, and after local dipolarization. These emissions are associated with an electron temperature anisotropy α=T⊥e/T||e>1 consistent with the linear theory of whistler mode anisotropy instability. When the whistler mode emissions are observed the measured electron anisotropy varies inversely with β||e (the ratio of the electron parallel pressure to the magnetic pressure) as predicted by Gary and Wang (1996). Narrow band whistler emissions correspond to the small α existing before dipolarization whereas the broad band emissions correspond to large α observed during and after dipolarization. The energy in the whistler mode is leaving the current sheet and is propagating along the background magnetic field, towards the Earth. A simple time-independent description based on the Liouville's theorem indicates that the electron temperature anisotropy decreases with the distance along the magnetic field from the equator. Once this variation of α is taken into account, the linear theory predicts an equatorial origin for the whistler mode. The linear theory is also consistent with the observed bandwidth of wave emissions. Yet, the anisotropy required to be fully consistent with the observations is somewhat larger than the measured one. Although the discrepancy remains within the instrumental error bars, this could be due to time-dependent effects which have been neglected. The possible role of the whistler waves in the substorm process is discussed.
- Published
- 2009
29. Earth’s ionospheric outflow dominated by hidden cold plasma
- Author
-
H. Vaith, Roy B. Torbert, Mats André, Christopher Cully, Erik Engwall, and Anders Eriksson
- Subjects
Physics ,Geophysics ,Plasma ,Physics::Geophysics ,Ion ,Atmosphere ,Physics::Plasma Physics ,Physics::Space Physics ,Astrophysics::Solar and Stellar Astrophysics ,General Earth and Planetary Sciences ,Outflow ,Astrophysics::Earth and Planetary Astrophysics ,Ionosphere ,Earth (classical element) - Abstract
The Earth constantly loses matter, mostly in the form of H+and O+ ions, through various outflow processes from the upper atmosphere and ionosphere. Most of these ions are cold (below 1 eV in therma ...
- Published
- 2008
30. The Electric Field Instrument (EFI) for THEMIS
- Author
-
Gregory T. Delory, Peter Harvey, Vassilis Angelopoulos, F. S. Mozer, Christopher Cully, A. J. Hull, John W. Bonnell, and Robert E. Ergun
- Subjects
Physics ,Spacecraft ,business.industry ,Acoustics ,Astronomy and Astrophysics ,Space and Planetary Science ,Electric field ,Physics::Space Physics ,Broadband ,Waveform ,Astrophysics::Earth and Planetary Astrophysics ,Electronics ,Antenna (radio) ,business ,Spin (aerodynamics) ,Communication channel - Abstract
The design, performance, and on-orbit operation of the three-axis electric field instrument (EFI) for the NASA THEMIS mission is described. The 20 radial wire boom and 10 axial stacer boom antenna systems making up the EFI sensors on the five THEMIS spacecraft, along with their supporting electronics have been deployed and are operating successfully on-orbit without any mechanical or electrical failures since early 2007. The EFI provides for waveform and spectral three-axis measurements of the ambient electric field from DC up to 8 kHz, with a single, integral broadband channel extending up to 400 kHz. Individual sensor potentials are also measured, providing for on-board and ground-based estimation of spacecraft floating potential and high-resolution plasma density measurements. Individual antenna baselines are 50- and 40-m in the spin plane, and 6.9-m along the spin axis.
- Published
- 2008
31. The THEMIS Digital Fields Board
- Author
-
Robert E. Ergun, K. Stevens, Christopher Cully, A. Nammari, and J. Westfall
- Subjects
Physics ,Signal processing ,Spacecraft ,Magnetometer ,business.industry ,Acoustics ,Astronomy and Astrophysics ,law.invention ,Power (physics) ,Search coil ,Data acquisition ,Nuclear magnetic resonance ,Space and Planetary Science ,law ,Electric field ,Physics::Space Physics ,Electric power ,business - Abstract
The Digital Fields Board (DFB) performs the data acquisition and signal processing for the Electric Fields Instrument and Search Coil Magnetometer on each of the THEMIS (Time History of Events and Macroscale Interactions during Substorms) satellites. The processing is highly flexible and low-power (∼1.1 watt orbit-averaged). The primary data products are time series waveforms and wave power spectra of the electric and magnetic fields. The power spectra can be computed either on the raw signals (i.e. in a system co-rotating with the spacecraft) or in a coordinate system aligned with the local DC magnetic field. Other data products include spectral power from multiple passbands (filter banks) and electric power in the 30–500 kHz band. The DFBs on all five spacecraft have been turned on and checked out in-flight, and are functioning as designed.
- Published
- 2008
32. Investigation into the spatial and temporal coherence of ionospheric outflow on January 9–12, 1997
- Author
-
H. L. Collin, M. Boehm, Christopher Cully, W. K. Peterson, Andrew W. Yau, and Gang Lu
- Subjects
Physics ,Atmospheric Science ,Astrophysics::High Energy Astrophysical Phenomena ,Magnetosphere ,Geophysics ,Space weather ,Atmospheric sciences ,Ion ,Earth's magnetic field ,Space and Planetary Science ,Physics::Space Physics ,Polar ,Outflow ,Ionosphere ,Coherence (physics) - Abstract
Long term average ion outflow data derived from the Dynamics Explorer 1 Energetic Ion Mass Spectrometer data revealed very strong correlation between the net global ion outflow rate and measures of geomagnetic and solar activity as parameterized by the 3 hour Kp, 1 hour AE and Dst, and daily F10.7 indices. We use mass-resolved ion outflow observations from the Akebono, Polar, and FAST satellites obtained during a four day interval to assess the temporal and spatial coherence of ionospheric outflow on shorter time and smaller spatial scales. We find no relationship between locally measured ion outflow and a five minute resolution global monitor of energy exchanged between the ionosphere and magnetosphere. We discuss the implications of this result on models of the magnetosphere that include transport of ions from the ionosphere through the various regions of the magnetosphere.
- Published
- 2002
33. Observational evidence of electron pitch angle scattering driven by ECH waves
- Author
-
Hiroaki Misawa, Vassilis Angelopoulos, Mitsuru Hikishima, Christopher Cully, Satoshi Kurita, Yoshizumi Miyoshi, Olivier Le Contel, Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,Waves in plasmas ,business.industry ,Scattering ,Cyclotron ,Electron ,01 natural sciences ,Computational physics ,law.invention ,Observational evidence ,Geophysics ,Distribution function ,Optics ,law ,[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,0103 physical sciences ,Physics::Space Physics ,General Earth and Planetary Sciences ,Pitch angle ,Diffusion curve ,business ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences - Abstract
International audience; Using the plasma wave and electron data obtained from Time History of Events and Macroscale Interactions during Substorms, we show a signature of electron pitch angle scattering driven by Electrostatic Cyclotron Harmonic (ECH) waves in the velocity distribution function (VDF). The diffusion curve of whistler mode waves is used as a proxy to identify changes in VDFs due to wave-particle interactions. We confirm that the shape of the VDF well agrees with the diffusion curve of whistler mode waves when whistler mode chorus alone is active. On the other hand, we find that the shape of the VDF deviates from the diffusion curves at low pitch angles when ECH waves are active following the inactivation of chorus waves. The result is observational support for electron pitch angle scattering caused by ECH waves and suggests that ECH waves can contribute to generation of diffuse auroras.
- Published
- 2014
34. On the origin of falling-tone chorus elements in Earth's inner magnetosphere
- Author
-
O. Le Contel, Vassilis Angelopoulos, Anton Artemyev, G. Rolland, Hugo Breuillard, Christopher Cully, Yu. A. Zaliznyak, Vladimir Krasnoselskikh, Oleksiy Agapitov, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), National Taras Shevchenko University of Kyiv, Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Calgary], University of Calgary, Institute of Geophysics and Planetary Physics [San Diego] (IGPP), Scripps Institution of Oceanography (SIO - UC San Diego), University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC)-University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC), Plasma Theory Department, Institute for Nuclear Research, Centre National d'Études Spatiales [Toulouse] (CNES), CNES through the grant 'Modèles d’ondes'., Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Scripps Institution of Oceanography (SIO), University of California-University of California-University of California [San Diego] (UC San Diego), and University of California-University of California
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,Magnetic dip ,Magnetosphere ,01 natural sciences ,7. Clean energy ,Physics::Geophysics ,Latitude ,symbols.namesake ,0103 physical sciences ,Earth and Planetary Sciences (miscellaneous) ,Very low frequency ,lcsh:Science ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Physics ,biology ,lcsh:QC801-809 ,Chorus ,Geology ,Astronomy and Astrophysics ,Geophysics ,biology.organism_classification ,lcsh:QC1-999 ,Magnetic field ,lcsh:Geophysics. Cosmic physics ,Space and Planetary Science ,Auroral chorus ,[SDU]Sciences of the Universe [physics] ,Van Allen radiation belt ,Physics::Space Physics ,symbols ,lcsh:Q ,lcsh:Physics - Abstract
Generation of extremely/very low frequency (ELF/VLF) chorus waves in Earth's inner magnetosphere has received increased attention recently because of their significance for radiation belt dynamics. Though past theoretical and numerical models have demonstrated how rising-tone chorus elements are produced, falling-tone chorus element generation has yet to be explained. Our new model proposes that weak-amplitude falling-tone chorus elements can be generated by magnetospheric reflection of rising-tone elements. Using ray tracing in a realistic plasma model of the inner magnetosphere, we demonstrate that rising-tone elements originating at the magnetic equator propagate to higher latitudes. Upon reflection there, they propagate to lower L-shells and turn into oblique falling tones of reduced power, frequency, and bandwidth relative to their progenitor rising tones. Our results are in good agreement with comprehensive statistical studies of such waves, notably using magnetic field measurements from THEMIS (Time History of Events and Macroscale Interactions during Substorms) spacecraft. Thus, we conclude that the proposed mechanism can be responsible for the generation of weak-amplitude falling-tone chorus emissions.
- Published
- 2014
35. In-flight calibration of double-probe electric field measurements on Cluster
- Author
-
Per-Arne Lindqvist, Yuri V. Khotyaintsev, Anders Eriksson, Christopher Cully, and Mats André
- Subjects
Physics ,Atmospheric Science ,Offset (computer science) ,Spacecraft ,business.industry ,Double probe ,lcsh:QC801-809 ,Electrical engineering ,Geology ,Plasma ,Oceanography ,Space exploration ,lcsh:Geophysics. Cosmic physics ,Electric field ,Physics::Space Physics ,Physical Sciences ,Fysik ,Aerospace engineering ,business ,Spinning - Abstract
Double-probe electric field instrument with long wire booms is one of the most popular techniques for in situ measurement of electric fields in plasmas on spinning spacecraft platforms, which have been employed on a large number of space missions. Here we present an overview of the calibration procedure used for the Electric Field and Wave (EFW) instrument on Cluster, which involves spin fits of the data and correction of several offsets. We also describe the procedure for the offset determination and present results for the long-term evolution of the offsets.
- Published
- 2014
36. Quantified energy dissipation rates in the terrestrial bow shock: 1. Analysis techniques and methodology
- Author
-
Drew Turner, Lynn B. Wilson, Vassilis Angelopoulos, David M. Malaspina, Aaron Breneman, O. Le Contel, David G. Sibeck, Christopher Cully, Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Shock wave ,Physics ,Mechanics ,Dissipation ,symbols.namesake ,Geophysics ,Classical mechanics ,Mach number ,Space and Planetary Science ,Bow wave ,Electromagnetism ,[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,Electric field ,symbols ,Bow shock (aerodynamics) ,Total energy ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] - Abstract
International audience; We present a detailed outline and discussion of the analysis techniques used to compare the relevance of different energy dissipation mechanisms at collisionless shock waves. We show that the low-frequency, quasi-static fields contribute less to ohmic energy dissipation, (-j·E), than their high-frequency counterparts. In fact, we found that high-frequency, large-amplitude (>100 mV/m and/or >1 nT) waves are ubiquitous in the transition region of collisionless shocks. We quantitatively show that their fields, through wave-particle interactions, cause enough energy dissipation to regulate the global structure of collisionless shocks. The purpose of this paper, part one of two, is to outline and describe in detail the background, analysis techniques, and theoretical motivation for our new results presented in the companion paper. The companion paper presents the results of our quantitative energy dissipation rate estimates and discusses the implications. Together, the two manuscripts present the first study quantifying the contribution that high-frequency waves provide, through wave-particle interactions, to the total energy dissipation budget of collisionless shock waves.
- Published
- 2014
37. Wave normal angles of whistler-mode chorus rising and falling tones
- Author
-
Olivier Le Contel, Ondrej Santolik, Yuri V. Khotyaintsev, Ulrich Taubenschuss, Christopher Cully, Vassilis Angelopoulos, Andris Vaivads, Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Physics ,business.industry ,Magnetic dip ,Plasmasphere ,Polarization (waves) ,Computational physics ,Magnetic field ,Dipole ,Geophysics ,Optics ,Space and Planetary Science ,[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,Electric field ,Magnetopause ,Ligand cone angle ,business ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] - Abstract
International audience; We present a study of wave normal angles (θk) of whistler mode chorus emission as observed by Time History of Events and Macroscale Interactions during Substorms (THEMIS) during the year 2008. The three inner THEMIS satellites THA, THD, and THE usually orbit Earth close to the dipole magnetic equator (±20°), covering a large range of L shells from the plasmasphere out to the magnetopause. Waveform measurements of electric and magnetic fields enable a detailed polarization analysis of chorus below 4 kHz. When displayed in a frequency-θk histogram, four characteristic regions of occurrence are evident. They are separated by gaps at f/fc,e≈0.5 (f is the chorus frequency, fc,e is the local electron cyclotron frequency) and at θk∼40°. Below θk∼40°, the average value for θk is predominantly field aligned, but slightly increasing with frequency toward half of fc,e (θk up to 20°). Above half of fc,e, the average θk is again decreasing with frequency. Above θk∼40°, wave normal angles are usually close to the resonance cone angle. Furthermore, we present a detailed comparison of electric and magnetic fields of chorus rising and falling tones. Falling tones exhibit peaks in occurrence solely for θk>40° and are propagating close to the resonance cone angle. Nevertheless, when comparing rising tones to falling tones at θk>40°, the ratio of magnetic to electric field shows no significant differences. Thus, we conclude that falling tones are generated under similar conditions as rising tones, with common source regions close to the magnetic equatorial plane.
- Published
- 2014
38. The quasi-electrostatic mode of chorus waves and electron nonlinear acceleration
- Author
-
Oleksiy Agapitov, Christopher Cully, Anton Artemyev, Didier Mourenas, Vladimir Krasnoselskikh, Vassilis Angelopoulos, John W. Bonnell, O. Le Contel, Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Centre d'Études de Limeil-Valenton (CEA-DAM), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Calgary], University of Calgary, Institute of Geophysics and Planetary Physics [San Diego] (IGPP), Scripps Institution of Oceanography (SIO), University of California [San Diego] (UC San Diego), University of California-University of California-University of California [San Diego] (UC San Diego), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Scripps Institution of Oceanography (SIO - UC San Diego), and University of California (UC)-University of California (UC)-University of California [San Diego] (UC San Diego)
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,Field line ,Magnetosphere ,Trapping ,Electron ,01 natural sciences ,Resonance (particle physics) ,Computational physics ,Acceleration ,Nonlinear system ,Geophysics ,Space and Planetary Science ,[SDU]Sciences of the Universe [physics] ,0103 physical sciences ,Physics::Space Physics ,Particle ,Atomic physics ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences - Abstract
International audience; Selected Time History of Events and Macroscale Interactions During Substorms observationsat medium latitudes of highly oblique and high-amplitude chorus waves are presented and analyzed. Thepresence of such very intense waves is expected to have important consequences on electron energizationin the magnetosphere. An analytical model is therefore developed to evaluate the efficiency of the trappingand acceleration of energetic electrons via Landau resonance with such nearly electrostatic chorus waves.Test-particle simulations are then performed to illustrate the conclusions derived from the analytical model,using parameter values consistent with observations. It is shown that the energy gain can be much largerthan the initial particle energy for 10 keV electrons, and it is further demonstrated that this energy gain isweakly dependent on the density variation along field lines.
- Published
- 2014
39. The Electric Field and Waves Instruments on the Radiation Belt Storm Probes Mission
- Author
-
Vladimir Krasnoselskikh, Greg Dalton, W. Rachelson, Robert J. Strangeway, Stuart D. Bale, C. Shultz, Cynthia A Cattell, J. Fischer, D. M. Malsapina, John C. Foster, Ian R. Mann, Xinlin Li, D. Gordon, Jay M. Albert, S. Heavner, Peter Berg, R. Hochmann, Eric Donovan, A. Brenneman, J. McCauley, C. C. Chaston, Peter Harvey, Paul Turin, Michael Ludlam, F. S. Mozer, Kris Kersten, M. Bolton, Mary K. Hudson, B. Donakowski, John R. Wygant, Keith Goetz, M. Diaz-Aguado, Daniel N. Baker, Robert E. Ergun, Christopher Cully, J. B. Tao, K. Harps, John W. Bonnell, Christopher D. Smith, School of Physics and Astronomy [Minneapolis], University of Minnesota [Twin Cities] (UMN), University of Minnesota System-University of Minnesota System, Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Blackett Laboratory, Imperial College London, Department of Physics and Astronomy [Newark], University of Delaware [Newark], Institute of Geophysics and Planetary Physics [Los Angeles] (IGPP), University of California [Los Angeles] (UCLA), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), MIT Haystack Observatory, Massachusetts Institute of Technology (MIT), Department of Physics [Edmonton], University of Alberta, Department of Physics and Astronomy [Calgary], University of Calgary, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Haystack Observatory, and Foster, John C.
- Subjects
Physics ,Electric fields ,010504 meteorology & atmospheric sciences ,Spacecraft ,business.industry ,Acoustics ,Magnetosphere ,Astronomy and Astrophysics ,Optical field ,01 natural sciences ,Magnetic field ,[SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] ,symbols.namesake ,Nuclear magnetic resonance ,Space and Planetary Science ,Electric field ,Van Allen radiation belt ,0103 physical sciences ,symbols ,Van Allen Probes ,business ,010303 astronomy & astrophysics ,Burst mode (computing) ,0105 earth and related environmental sciences - Abstract
The Electric Fields and Waves (EFW) Instruments on the two Radiation Belt Storm Probe (RBSP) spacecraft (recently renamed the Van Allen Probes) are designed to measure three dimensional quasi-static and low frequency electric fields and waves associated with the major mechanisms responsible for the acceleration of energetic charged particles in the inner magnetosphere of the Earth. For this measurement, the instrument uses two pairs of spherical double probe sensors at the ends of orthogonal centripetally deployed booms in the spin plane with tip-to-tip separations of 100 meters. The third component of the electric field is measured by two spherical sensors separated by ∼15 m, deployed at the ends of two stacer booms oppositely directed along the spin axis of the spacecraft. The instrument provides a continuous stream of measurements over the entire orbit of the low frequency electric field vector at 32 samples/s in a survey mode. This survey mode also includes measurements of spacecraft potential to provide information on thermal electron plasma variations and structure. Survey mode spectral information allows the continuous evaluation of the peak value and spectral power in electric, magnetic and density fluctuations from several Hz to 6.5 kHz. On-board cross-spectral data allows the calculation of field-aligned wave Poynting flux along the magnetic field. For higher frequency waveform information, two different programmable burst memories are used with nominal sampling rates of 512 samples/s and 16 k samples/s. The EFW burst modes provide targeted measurements over brief time intervals of 3-d electric fields, 3-d wave magnetic fields (from the EMFISIS magnetic search coil sensors), and spacecraft potential. In the burst modes all six sensor-spacecraft potential measurements are telemetered enabling interferometric timing of small-scale plasma structures. In the first burst mode, the instrument stores all or a substantial fraction of the high frequency measurements in a 32 gigabyte burst memory. The sub-intervals to be downloaded are uplinked by ground command after inspection of instrument survey data and other information available on the ground. The second burst mode involves autonomous storing and playback of data controlled by flight software algorithms, which assess the “highest quality” events on the basis of instrument measurements and information from other instruments available on orbit. The EFW instrument provides 3-d wave electric field signals with a frequency response up to 400 kHz to the EMFISIS instrument for analysis and telemetry (Kletzing et al. Space Sci. Rev. 2013)., United States. National Aeronautics and Space Administration (Contract NAS5-01072), Johns Hopkins University. Applied Physics Laboratory (Radiation Storm Belt Probes ECT Contract 967399), Johns Hopkins University. Applied Physics Laboratory (Radiation Storm Belt Probes EFW Contract 922613)
- Published
- 2013
40. Characteristics of the Poynting flux and wave normal vectors of whistler-mode waves observed on THEMIS
- Author
-
J. B. Tao, Richard M. Thorne, Yukitoshi Nishimura, Lunjin Chen, Jacob Bortnik, Wen Li, O. LeContel, Christopher Cully, John W. Bonnell, Vassilis Angelopoulos, Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,Wave propagation ,Plane wave ,Geophysics ,01 natural sciences ,010305 fluids & plasmas ,Computational physics ,13. Climate action ,Space and Planetary Science ,Surface wave ,[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,Wave shoaling ,0103 physical sciences ,Poynting vector ,Physics::Space Physics ,Wave vector ,Mechanical wave ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Longitudinal wave ,0105 earth and related environmental sciences - Abstract
International audience; The characteristics of the Poynting flux and wave normal vectors of whistler-mode waves outside the plasmapause are investigated for the lower (0.1-0.5 fce) and upper bands (0.5-0.8 fce), where fce is the equatorial electron cyclotron frequency. To analyze the wave properties, we utilized high-resolution waveform data from multiple THEMIS spacecraft in the near-equatorial magnetosphere from June 2008 to November 2012. Full measurements of the wave electric and magnetic fields are used to calculate the Poynting fluxes and construct the wave normal vectors, which are then used to calculate the polar and azimuthal angles with respect to the background magnetic field. Statistical results show that the majority of whistler-mode waves propagate away from the magnetic equator, suggesting that the major source region is very close to the equator. The lower band wave normal angle distribution shows a major peak close to the field line direction and a secondary peak near the resonance cone. In contrast, the wave normal distribution of upper band waves exhibits a broad distribution between 0° and 60° with the largest probability at ~0°. The azimuthal component of the wave normal vector predominantly points radially outward for both lower and upper band waves, but a tendency for azimuthal propagation is observed for lower band waves in the day and dusk sectors probably due to pronounced azimuthal density gradients in the afternoon sector. Our statistical results provide crucial information on the Poynting fluxes and wave normal vectors of whistler-mode waves, which play a significant role in radiation belt electron dynamics.
- Published
- 2013
41. Source location of falling tone chorus
- Author
-
Hiroaki Misawa, Olivier Le Contel, Vassilis Angelopoulos, Satoshi Kurita, and Christopher Cully
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,Meteorology ,biology ,Chorus ,Magnetic dip ,Astrophysics ,biology.organism_classification ,01 natural sciences ,Latitude ,Tone (musical instrument) ,Geophysics ,Auroral chorus ,0103 physical sciences ,Poynting vector ,General Earth and Planetary Sciences ,Whistler mode ,Falling (sensation) ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences - Abstract
[1] Chorus is characterized by its fine structures consisting of rising or falling tones believed to result from nonlinear wave-particle interactions. However, previous studies have showed that the intensity and propagation characteristics of rising and falling tone chorus are quite different, suggesting that their generation processes might be different. In this paper, the propagation direction of falling tone chorus is statistically investigated to identify its source region based on the Poynting vector measurement with THEMIS. The result shows that the falling tone chorus propagates from the magnetic equator to higher latitude both in the northern and southern hemispheres, in the same way as rising tone chorus. Our result shows that the magnetic equator is the common source location for both rising and falling tone chorus. The result emphasizes that the different properties between rising and falling tone chorus originate from their generation mechanism rather than source region.
- Published
- 2012
42. THEMIS observation of chorus elements without a gap at half the gyrofrequency
- Author
-
Hiroaki Misawa, Satoshi Kurita, Christopher Cully, O. Le Contel, Yoshiharu Omura, Yuto Katoh, and Vassilis Angelopoulos
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,Meteorology ,Soil Science ,Magnetic dip ,Aquatic Science ,Oceanography ,01 natural sciences ,Sweep frequency response analysis ,Physics::Geophysics ,Tone (musical instrument) ,Geochemistry and Petrology ,0103 physical sciences ,Earth and Planetary Sciences (miscellaneous) ,Waveform ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Water Science and Technology ,Physics ,Ecology ,biology ,Chorus ,Paleontology ,Forestry ,biology.organism_classification ,Computational physics ,Nonlinear system ,Geophysics ,Amplitude ,Space and Planetary Science ,Auroral chorus ,Physics::Space Physics - Abstract
[1] Using waveform data obtained by one of the THEMIS satellites, we report properties of rising tone chorus elements without a gap at half the gyrofrequency in a region close to the magnetic equator. The wave normal angle of the chorus elements is typically field-aligned in the entire frequency range of both upper-band and lower-band chorus emissions. We find that the observed frequency sweep rates are consistent with the estimation based on the nonlinear wave growth theory of Omura et al. (2008). In addition, we compare the frequency profiles of the chorus wave amplitudes with those of the optimum and threshold wave amplitudes derived from the nonlinear wave growth theory for triggering rising tone chorus emissions. The results of the comparison show a reasonable agreement, indicating that rising tone chorus elements are continually generated through a triggering process which generates elements with the optimum amplitudes for nonlinear growth.
- Published
- 2012
43. Electron acceleration in the reconnection diffusion region: Cluster observations
- Author
-
Alessandro Retinò, Jiansen He, Yuri V. Khotyaintsev, X. H. Deng, Fouad Sahraoui, Huishan Fu, Shiyong Huang, Christopher Cully, Mats André, Y. Pang, Zhigang Yuan, Andris Vaivads, and Meng Zhou
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,Electron ,Cluster (spacecraft) ,01 natural sciences ,010305 fluids & plasmas ,Current sheet ,Geophysics ,Electron acceleration ,Physics::Space Physics ,0103 physical sciences ,General Earth and Planetary Sciences ,Diffusion (business) ,Atomic physics ,0105 earth and related environmental sciences - Abstract
We present one case study of magnetic islands and energetic electrons in the reconnection diffusion region observed by the Cluster spacecraft. The cores of the islands are characterized by strong c ...
- Published
- 2012
44. Kinetic instabilities in the lunar wake: ARTEMIS observations
- Author
-
Martin V. Goldman, J. Tao, Robert E. Ergun, Wolfgang Baumjohann, Christopher Cully, H. U. Auster, Jasper Halekas, Karl-Heinz Glassmeier, J. P. McFadden, David Newman, Davin Larson, John W. Bonnell, Vassilis Angelopoulos, and Laila Andersson
- Subjects
Atmospheric Science ,Soil Science ,Electron ,Aquatic Science ,Wake ,Oceanography ,Kinetic energy ,Acceleration ,Geochemistry and Petrology ,Electric field ,Earth and Planetary Sciences (miscellaneous) ,Earth-Surface Processes ,Water Science and Technology ,Physics ,Ecology ,Turbulence ,Astrophysics::Instrumentation and Methods for Astrophysics ,Paleontology ,Forestry ,Geophysics ,Computational physics ,Wavelength ,Space and Planetary Science ,Physics::Space Physics ,Cathode ray ,Astrophysics::Earth and Planetary Astrophysics - Abstract
[1] The Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon’s Interaction with the Sun (ARTEMIS) mission is a new two-probe lunar mission derived from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission. On 13 February 2010, one of the two probes, ARTEMIS P1 (formerly THEMIS-B), made the first lunar wake flyby of the mission. We present detailed analysis of the electrostatic waves observed on the outbound side of the flyby that were associated with electron beams. Halekas et al. (2011) derived a net potential across the lunar wake from observations and suggested that the net potential generated the observed electron beams and the electron beams in turn excited the observed electrostatic waves due to kinetic instabilities. The wavelengths and velocities of the electrostatic waves are estimated, using high-resolution electric field instrument data with cross-spectrum analysis and cross-correlation analysis. In general, the estimated wavelengths vary from a few hundred meters to a couple of thousand meters. The estimated phase velocities are on the order of 1000 km s � 1 . In addition, we perform 1-D Vlasov simulations to help identify the mode of the observed electrostatic waves. We conclude that the observed electrostatic waves are likely on the electron beam mode branch.
- Published
- 2012
45. Low-energy ions: A previously hidden solar system particle population
- Author
-
Mats André and Christopher Cully
- Subjects
Physics ,Solar System ,Atmospheric escape ,Magnetosphere ,Astronomy ,Magnetic reconnection ,Astrobiology ,Solar wind ,Geophysics ,Polar wind ,Physics::Plasma Physics ,Planet ,Physics::Space Physics ,General Earth and Planetary Sciences ,Astrophysics::Earth and Planetary Astrophysics ,Ionosphere - Abstract
[1] Ions with energies less than tens of eV originate from the Terrestrial ionosphere and from several planets and moons in the solar system. The low energy indicates the origin of the plasma but also severely complicates detection of the positive ions onboard sunlit spacecraft at higher altitudes, which often become positively charged to several tens of Volts. We discuss some methods to observe low-energy ions, including a recently developed technique based on the detection of the wake behind a charged spacecraft in a supersonic flow. Recent results from this technique show that low-energy ions typically dominate the density in large regions of the Terrestrial magnetosphere on the nightside and in the polar regions. These ions also often dominate in the dayside magnetosphere, and can change the dynamics of processes like magnetic reconnection. The loss of this low-energy plasma to the solar wind is one of the primary pathways for atmospheric escape from planets in our solar system. We combine several observations to estimate how common low-energy ions are in the Terrestrial magnetosphere and briefly compare with Mars, Venus and Titan.
- Published
- 2012
46. A model of electromagnetic electron phase-space holes and its application
- Author
-
David Newman, Wolfgang Baumjohann, Vassilis Angelopoulos, H. U. Auster, Alain Roux, O. LeContel, John W. Bonnell, Davin Larson, Robert E. Ergun, J. P. McFadden, Martin V. Goldman, Christopher Cully, Laila Andersson, Karl-Heinz Glassmeier, and J. Tao
- Subjects
Shock wave ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,Lorentz transformation ,Soil Science ,Electron ,Aquatic Science ,Oceanography ,Space (mathematics) ,01 natural sciences ,symbols.namesake ,Geochemistry and Petrology ,Quantum mechanics ,0103 physical sciences ,Earth and Planetary Sciences (miscellaneous) ,010306 general physics ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Water Science and Technology ,Physics ,Ecology ,Mathematics::Complex Variables ,Plasma sheet ,Paleontology ,Forestry ,Plasma ,Nonlinear system ,Geophysics ,Space and Planetary Science ,Phase space ,Quantum electrodynamics ,symbols - Abstract
[1] Electron phase-space holes (EHs) are indicators of nonlinear activities in space plasmas. Most often they are observed as electrostatic signals, but recently Andersson et al. [2009] reported electromagnetic EHs observed by the THEMIS mission in the Earth's plasma sheet. As a follow-up to Andersson et al. [2009], this paper presents a model of electromagnetic EHs where the δE × B0 drift of electrons creates a net current. The model is examined with test-particle simulations and compared to the electromagnetic EHs reported by Andersson et al. [2009]. As an application of the model, we introduce a more accurate method than the simplified Lorentz transformation of Andersson et al. [2009] to derive EH velocity (vEH). The sizes and potentials of EHs are derived from vEH, so an accurate derivation of vEH is important in analyzing EHs. In general, our results are qualitatively consistent with those of Andersson et al. [2009] but generally with smaller velocities and sizes.
- Published
- 2011
47. Multievent study of the correlation between pulsating aurora and whistler mode chorus emissions
- Author
-
Jacob Bortnik, Christopher Cully, Richard M. Thorne, Stephen B. Mende, O. Le Contel, Wen Li, John W. Bonnell, Larry R. Lyons, Vassilis Angelopoulos, U. Auster, Robert E. Ergun, Yukitoshi Nishimura, and Lunjin Chen
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,Point source ,Soil Science ,Magnetic dip ,Astrophysics ,Aquatic Science ,Oceanography ,01 natural sciences ,Physics::Geophysics ,Geochemistry and Petrology ,0103 physical sciences ,Earth and Planetary Sciences (miscellaneous) ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Water Science and Technology ,Physics ,Ecology ,biology ,Spacecraft ,business.industry ,Chorus ,Paleontology ,Forestry ,Geophysics ,biology.organism_classification ,Space and Planetary Science ,Auroral chorus ,Quasiperiodic function ,Physics::Space Physics ,Ionosphere ,business ,Excitation - Abstract
[1] A multievent study was performed using conjugate measurements of the Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft and an all-sky imager during periods of intense lower-band chorus waves. The thirteen identified cases support our previous finding, based on two events, that the intensity modulation of lower-band chorus near the magnetic equator is highly correlated with quasiperiodic pulsating auroral emissions near the spacecraft's magnetic footprint, indicating that lower-band chorus is the driver of the pulsating aurora. Furthermore, we identified a fortuitous measurement made simultaneously by two THEMIS spacecraft with small spatial separation. The two spacecraft were found to be located in a single pulsating chorus patch and the spacecraft footprints were in the same pulsating auroral patch when intense chorus bursts were measured simultaneously, whereas only one of the spacecraft's footprints was in a patch when the other spacecraft did not detect intense chorus. On the basis of this event, we can estimate the pulsating chorus patch size by mapping the pulsating auroral patches from the ionosphere toward the magnetic equator, giving a roughly circular region of ∼5000 km diameter for corresponding azimuthally elongated patches with ∼100 km size in the ionosphere. Using a ray-tracing-based calculation of the divergence of chorus raypaths from a point source, together with the corresponding resonant energies, we found that the chorus patch size is most probably not a result of ray divergence but a property of the wave excitation region.
- Published
- 2011
48. Global distribution of electrostatic electron cyclotron harmonic waves observed on THEMIS
- Author
-
Olivier Le Contel, Jun Liang, Xiao-Jia Zhang, Alain Roux, Wen Li, Michael Hartinger, Christopher Cully, Richard M. Thorne, Vassilis Angelopoulos, and Binbin Ni
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,Cyclotron ,Magnetic dip ,Magnetosphere ,Electron ,01 natural sciences ,law.invention ,Geophysics ,Amplitude ,13. Climate action ,Global distribution ,law ,Physics::Space Physics ,0103 physical sciences ,Harmonic ,General Earth and Planetary Sciences ,Statistical analysis ,Atomic physics ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences - Abstract
[1] A global, statistical analysis of electrostatic electron cyclotron harmonic (ECH) waves is performed using THEMIS wave data. Our results confirm the high occurrence of 5). The strongest (≥1 mV/m) ECH waves are enhanced during geomagnetically disturbed periods, and are mainly confined close to the magnetic equator (∣λ∣ 8) magnetosphere where chorus emissions are statistically weak.
- Published
- 2011
49. Observational evidence of the generation mechanism for rising-tone chorus
- Author
-
Uli Auster, O. Le Contel, Vassilis Angelopoulos, Christopher Cully, and John W. Bonnell
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,biology ,Chorus ,Magnetosphere ,Geophysics ,biology.organism_classification ,01 natural sciences ,Electromagnetic radiation ,Computational physics ,symbols.namesake ,Amplitude ,13. Climate action ,Auroral chorus ,Van Allen radiation belt ,Physics::Space Physics ,0103 physical sciences ,Chirp ,symbols ,General Earth and Planetary Sciences ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Free parameter - Abstract
[1] Chorus emissions are a striking feature of the electromagnetic wave environment in the Earth's magnetosphere. These bursts of whistler-mode waves exhibit characteristic frequency sweeps (chirps) believed to result from wave-particle trapping of cyclotron-resonant particles. Based on the theory of Omura et al. (2008), we predict the sweep rates of chorus elements observed by the THEMIS satellites. The predictions use independent observations of the electron distribution functions and have no free parameters. The predicted chirp rates are a function of wave amplitude, and this relation is clearly observed. The predictive success of the theory lends strong support to its underlying physical mechanism: cyclotron-resonant wave-particle trapping.
- Published
- 2011
50. Plasma jet braking: energy dissipation and nonadiabatic electrons
- Author
-
Andris Vaivads, Yuri V. Khotyaintsev, Christopher Cully, Mats André, and Christopher J. Owen
- Subjects
Physics ,Jet (fluid) ,Wave propagation ,Astrophysics::High Energy Astrophysical Phenomena ,Physics::Space Physics ,General Physics and Astronomy ,Electron temperature ,Magnetic reconnection ,Electron ,Atomic physics ,Betatron ,Electromagnetic radiation ,Magnetic flux - Abstract
We report in situ observations by the Cluster spacecraft of wave-particle interactions in a magnetic flux pileup region created by a magnetic reconnection outflow jet in Earth's magnetotail. Two distinct regions of wave activity are identified: lower-hybrid drift waves at the front edge and whistler-mode waves inside the pileup region. The whistler-mode waves are locally generated by the electron temperature anisotropy, and provide evidence for ongoing betatron energization caused by magnetic flux pileup. The whistler-mode waves cause fast pitch-angle scattering of electrons and isotropization of the electron distribution, thus making the flow braking process nonadiabatic. The waves strongly affect the electron dynamics and thus play an important role in the energy conversion chain during plasma jet braking.
- Published
- 2010
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.