G. Paschmann

Publications (160)118.05 Total impact

• Source

  Available from: lpl.arizona.edu

  Article: Cluster at the Magnetospheric Cusps

  P. J. Cargill, B. Lavraud, C. J. Owen, B. Grison, M. W. Dunlop, N. Cornilleau-Wehrlin, C. P. Escoubet, G. Paschmann, T. D. Phan, L. Rezeau, Y. Bogdanova, K. Nykyri
  Space Science Reviews 04/2012; 118(1):321-366. · 3.61 Impact Factor
• Source

  Available from: 129.177.40.15

  Article: Accuracy of multi-point boundary crossing time analysis

  J Vogt, S Haaland, G Paschmann
  [show abstract] [hide abstract]
  ABSTRACT: Recent multi-spacecraft studies of solar wind dis-continuity crossings using the timing (boundary plane tri-angulation) method gave boundary parameter estimates that are significantly different from those of the well-established single-spacecraft minimum variance analysis (MVA) tech-nique. A large survey of directional discontinuities in Cluster data turned out to be particularly inconsistent in the sense that multi-point timing analyses did not identify any rota-tional discontinuities (RDs) whereas the MVA results of the individual spacecraft suggested that RDs form the majority of events. To make multi-spacecraft studies of discontinu-ity crossings more conclusive, the present report addresses the accuracy of the timing approach to boundary parameter estimation. Our error analysis is based on the reciprocal vec-tor formalism and takes into account uncertainties both in crossing times and in the spacecraft positions. A rigorous error estimation scheme is presented for the general case of correlated crossing time errors and arbitrary spacecraft con-figurations. Crossing time error covariances are determined through cross correlation analyses of the residuals. The prin-cipal influence of the spacecraft array geometry on the accu-racy of the timing method is illustrated using error formulas for the simplified case of mutually uncorrelated and identical errors at different spacecraft. The full error analysis proce-dure is demonstrated for a solar wind discontinuity as ob-served by the Cluster FGM instrument.
  01/2011; 29:2239-2252.
• Article: Triggering of magnetic reconnection in a magnetosheath current sheet due to compression against the magnetopause

  T. D. Phan, T. E. Love, J. T. Gosling, G. Paschmann, J. P. Eastwood, M. Oieroset, V. Angelopoulos, J. P. McFadden, D. Larson, U. Auster
  [show abstract] [hide abstract]
  ABSTRACT: Triggers of magnetosheath reconnection identifiedThe bow shock disrupted reconnectionMagnetosheath reconnection heats electrons, unlike solar wind exhausts
  Geophysical Research Letters - GEOPHYS RES LETT. 01/2011; 38(17).
• Article: Oscillation of electron counts at 500 eV downstream of the quasi-perpendicular bow shock

  H Matsui, R B Torbert, W Baumjohann, H Kucharek, S J Schwartz, C G Mouikis, H Vaith, L M Kistler, E A Lucek, A N Fazakerley, B Miao, G Paschmann
  Journal of Geophysical Research-Space Physics. 01/2008; 113(A8).
• Article: Cluster observations of broadband ULF waves near the dayside polar cap boundary: Two detailed multi-instrument event studies

  H Matsui, P A Puhl-Quinn, R B Torbert, W Baumjohann, C J Farrugia, C G Mouikis, E A Lucek, P M E Decreau, G Paschmann
  Journal of Geophysical Research-Space Physics. 01/2007; 112(A7).
• Article: Statistics of high-altitude and high-latitude O+ ion outflows observed by Cluster/CIS

  S. Arvelius, M. Yamauchi, H. Nilsson, R. Lundin, Y. Hobara, H. Rème, M. B. Bavassano-Cattaneo, G. Paschmann, A. Korth, L. M. Kistler, G. K. Parks
  [show abstract] [hide abstract]
  ABSTRACT: The persistent outflows of O+ ions observed by the Cluster CIS/CODIF instrument were studied statistically in the high-altitude (from 3 up to 11 RE) and high-latitude (from 70 to ~90 deg invariant latitude, ILAT) polar region. The principal results are: (1) Outflowing O+ ions with more than 1keV are observed above 10 RE geocentric distance and above 85deg ILAT location; (2) at 6-8 RE geocentric distance, the latitudinal distribution of O+ ion outflow is consistent with velocity filter dispersion from a source equatorward and below the spacecraft (e.g. the cusp/cleft); (3) however, at 8-12 RE geocentric distance the distribution of O+ outflows cannot be explained by velocity filter only. The results suggest that additional energization or acceleration processes for outflowing O+ ions occur at high altitudes and high latitudes in the dayside polar region. Keywords. Magnetospheric physics (Magnetospheric configuration and dynamics, Solar wind-magnetosphere interactions)
  Annales Geophysicae 01/2005; 23(5):1909-1916. · 1.84 Impact Factor
• Article: Statistical study of relationships between dayside high-altitude and high-latitude O+ ion outflows, solar winds, and geomagnetic activity

  S Arvelius, M Yamauchi, H Nilsson, R Lundin, H Reme, MB Bavassano-Cattaneo, G Paschmann, A Korth, LM Kistler, GK Parks, others
  Annales Geophysicae 01/2005; 23:1909-1916. · 1.84 Impact Factor
• Chapter: Magnetopause Processes

  T. D. Phan, C. P. Escoubet, L. Rezeau, R. A. Treumann, A. Vaivads, G. Paschmann, S. A. Fuselier, D. Attié, B. Rogers, B. U. Ö. Sonnerup
  12/2004: pages 367-424;
• Chapter: Magnetopause and Boundary Layer

  J. De Keyser, M. W. Dunlop, C. J. Owen, B. U. Ö. Sonnerup, S. E. Haaland, A. Vaivads, G. Paschmann, R. Lundin, L. Rezeau
  12/2004: pages 231-320;
• Article: Structure of the magnetic reconnection diffusion region from four-spacecraft observations.

  A Vaivads, Y Khotyaintsev, M André, A Retinò, S C Buchert, B N Rogers, P Décréau, G Paschmann, T D Phan
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  ABSTRACT: Magnetic reconnection leads to energy conversion in large volumes in space but is initiated in small diffusion regions. Because of the small sizes of the diffusion regions, their crossings by spacecraft are rare. We report four-spacecraft observations of a diffusion region encounter at the Earth's magnetopause that allow us to reliably distinguish spatial from temporal features. We find that the diffusion region is stable on ion time and length scales in agreement with numerical simulations. The electric field normal to the current sheet is balanced by the Hall term in the generalized Ohm's law, E(n) approximately jxB/ne.n, thus establishing that Hall physics is dominating inside the diffusion region. The reconnection rate is fast, approximately 0.1. We show that strong parallel currents flow along the separatrices; they are correlated with observations of high-frequency Langmuir/upper hybrid waves.
  Physical Review Letters 10/2004; 93(10):105001. · 7.37 Impact Factor
• Source

  Available from: archives-ouvertes.fr

  Article: Reconstruction of two-dimensional magnetopause structures from Cluster observations: verification of method

  H Hasegawa, B. U. Ö. Sonnerup, M. W. Dunlop, A. Balogh, S. E. Haaland, B. Klecker, G. Paschmann, B. Lavraud, I. Dandouras, H. Rème
  [show abstract] [hide abstract]
  ABSTRACT: A recently developed technique for reconstructing approximately two-dimensional (?/?z˜0), time-stationary magnetic field structures in space is applied to two magnetopause traversals on the dawnside flank by the four Cluster spacecraft, when the spacecraft separation was about 2000km. The method consists of solving the Grad-Shafranov equation for magnetohydrostatic structures, using plasma and magnetic field data measured along a single spacecraft trajectory as spatial initial values. We assess the usefulness of this single-spacecraft-based technique by comparing the magnetic field maps produced from one spacecraft with the field vectors that other spacecraft actually observed. For an optimally selected invariant (z)-axis, the correlation between the field components predicted from the reconstructed map and the corresponding measured components reaches more than 0.97. This result indicates that the reconstruction technique predicts conditions at the other spacecraft locations quite well. The optimal invariant axis is relatively close to the intermediate variance direction, computed from minimum variance analysis of the measured magnetic field, and is generally well determined with respect to rotations about the maximum variance direction but less well with respect to rotations about the minimum variance direction. In one of the events, field maps recovered individually for two of the spacecraft, which crossed the magnetopause with an interval of a few tens of seconds, show substantial differences in configuration. By comparing these field maps, time evolution of the magnetopause structures, such as the formation of magnetic islands, motion of the structures, and thickening of the magnetopause current layer, is discussed. Key words. Magnetospheric physics (Magnetopause, cusp, and boundary layers) – Space plasma physics (Experimental and mathematical techniques, Magnetic reconnection)
  01/2004;
• Article: Fluid and particle signatures of dayside reconnection (vol 19, pg 1045, 2001)

  TM Bauer, G Paschmann, N Sckopke, RA Treumann, W Baumjohann, TD Phan
  Annales Geophysicae 01/2002; 20(4):583-583. · 1.84 Impact Factor
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  Available from: terrapub.co.jp

  Article: Evidence for an extended reconnection line at the dayside magnetopause

  T D Phan, M P Freeman, L M Kistler, B Klecker, G Haerendel, G Paschmann, O Sonnerup, W Baumjohann, M B Bavassano-Cattaneo, C W Carlson, A M Dilellis, K.-H Fornacon, L A Frank, M Fujimoto, E Georgescu, S Kokubun, E Moebius, T Mukai, W R Paterson, H Reme
  [show abstract] [hide abstract]
  ABSTRACT: We report in-situ detection by two spacecraft of oppositely directed jets of plasma emanating from a magnetic reconnection site at the Earth's dayside magnetopause, confirming a key element inherent in all reconnection scenarios. The dual-spacecraft (Equator-S and Geotail) observations at the flank magnetopause, together with SuperDARN Halley radar observations of the subsolar cusp region, reveal the presence of a rather stable and extended reconnection line which lies along the equatorial magnetopause. These observations were made under persistent southward interplanetary magnetic field (IMF) conditions, implying that under these conditions the reconnection sites are determined by the large-scale interactions between the solar wind magnetic field and the dayside magnetosphere, rather than by local conditions at the magnetopause. Control by local conditions would result in patchy reconnection, distributed in a less well-organized fashion over the magnetopause surface.
  Earth Planets and Space 01/2001; 53:619-625. · 0.80 Impact Factor
• Source

  Available from: articles.adsabs.harvard.edu

  Article: Improved Boundary Normal Calculations Using Minimum Variance Analysis and Wavelet De-Noising Techniques

  S. Haaland, G. Paschmann
  12/2000; 492:127.
• Source

  Available from: A. Korth

  Article: Evidence for interplanetary magnetic field B-y controlled large-scale reconnection at the dayside magnetopause

  MF Marcucci, MBB Cattaneo, AM Di Lellis, PC Irelli, LM Kistler, TD Phan, G Haerendel, B Klecker, G Paschmann, W Baumjohann, E Mobius, MA Popecki, JA Sauvaud, H Reme, A Korth, L Eliasson, CW Carlson, M McCarthy, GK Parks
  Journal of Geophysical Research-Space Physics. 01/2000; 105(A12):27497-27507.
• Article: Contributions of different source and loss processes to the plasma content of the magnetosphere

  B. Hultqvist, M. André, S.P. Christon, G. Paschmann, D.G. Sibeck
  Space Science Reviews 03/1999; 88(1):355-372. · 3.61 Impact Factor
• Article: Plasma transfer processes at the magnetopause

  D.G. Sibeck, G. Paschmann, R.A. Treumann, S.A. Fuselier, W. Lennartsson, M. Lockwood, R. Lundin, K.W. Ogilvie, T.G. Onsager, T.-D. Phan, M. Roth, M. Scholer, N. Sckopke, K. Stasiewicz, M. Yamauchi
  Space Science Reviews 03/1999; 88(1):207-283. · 3.61 Impact Factor
• Article: EDI convection measurements at 5–6 R E in the post-midnight region

  J. M. Quinn, G. Paschmann, N. Sckopke, V. K. Jordanova, H. Vaith, O. H. Bauer, W. Baumjohann, W. Fillius, G. Haerendel, S. S. Kerr, C. A. Kletzing, K. Lynch
  [show abstract] [hide abstract]
  ABSTRACT: We present the first triangulation measurements of electric fields with the electron drift instrument (EDI) on Equator-S. We show results from five high-data-rate passes of the satellite through the near-midnight equatorial region, at geocentric distances of approximately 5–6 RE, during geomagnetically quiet conditions. In a co-rotating frame of reference, the measured electric fields have magnitudes of a few tenths of mV/m, with the E × B drift generally directed sunward but with large variations. Temporal variations of the electric field on time scales of several seconds to minutes are large compared to the average magnitude. Comparisons of the “DC” baseline of the EDI-measured electric fields with the mapped Weimer ionospheric model and the Rowland and Wygant CRRES measurements yield reasonable agreement.
  Annales Geophysicae 01/1999; 17(12):1503-1512. · 1.84 Impact Factor
• Article: The Electron Drift Technique for Measuring Electric and Magnetic Fields

  G. Paschmann, C. E. Mcilwain, J. M. Quinn, R. B. Torbert, E. C. Whipple, John Christensen
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  ABSTRACT: The electron drift technique is based on sensing the drift of a weak beam of test electrons that is caused by electric fields and/or gradients in the magnetic field. These quantities can, by use of different electron energies, in principle be determined separately. Depending on the ratio of drift speed to magnetic field strength, the drift velocity can be determined either from the two emission directions that cause the electrons to gyrate back to detectors placed some distance from the emitting guns, or from measurements of the time of flight of the electrons. As a by-product of the time-of-flight measurements, the magnetic field strength is also determined. The paper describes strengths and weaknesses of the method as well as technical constraints.
  02/1998;
• Source

  Available from: articles.adsabs.harvard.edu

  Article: The Electron Drift Instrument for Cluster

  G. Paschmann, F. Melzner, R. Frenzel, H. Vaith, P. Parigger, U. Pagel, O. H. Bauer, G. Haerendel, W. Baumjohann, N. Scopke
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  ABSTRACT: The Electron Drift Instrument (EDI) measures the drift of a weak beam of test electrons that, when emitted in certain directions, return to the spacecraft after one or more gyrations. This drift is related to the electric field and the gradient in the magnetic field, and these quantities can, by use of different electron energies, be determined separately. As a by-product, the magnetic field strength is also measured. The present paper describes the scientific objectives, the experimental method, and the technical realization of the various elements of the instrument.
  02/1997;