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Study of nonthermal continuum patches : wave propagation and plasmapause study

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Grimald, S., El-Lemdani-Mazouz, F., Foullon, C. (Claire), Décréau, P. M. E., Boardsen, Scott Arnold and Vallières, Xavier. (2011) Study of nonthermal continuum patches : wave propagation and plasmapause study. Journal of Geophysical Research, Vol.116 . A07219 . ISSN 0148-0227

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Official URL: http://dx.doi.org/10.1029/2011JA016476

Abstract

Nonthermal continuum (NTC) radiation is believed to be emitted at the plasmapause and near the magnetic equator. We present a particular type of NTC radiation, referred to as NTC patch, which appears over a wide frequency range and within a relatively short time interval. NTC patches are observed in all magnetospheric plasma environments of the Cluster 2 orbit and are shown to represent a quarter of the NTC events observed in 2003. A statistical analysis of the frequency pattern performed on the 2003 Cluster 2 Waves of High frequency and Sounder for Probing of Electron Density by Relaxation data indicates that the NTC patches can be divided into two classes: Those with banded emission in frequency are only observed close to the source region and are thus termed "plasmaspheric," while the others, nonbanded, are termed "outer magnetospheric." In an event on 26 September 2003, we localize the sources positions and study the expected propagation of each NTC frequency beam of a plasmaspheric patch. From the observations, we show that the sources are located very close to the satellite and to each other at positions projected on the XY GSE plane. Using a ray tracing code, we demonstrate that, close to the source regions, the satellite observes all frequency rays at the same time which overlap in the spectrogram making up the plasmaspheric patch. After the satellite crossing, the rays follow diverging paths and cannot therefore be observed further out by the same satellite simultaneously. Plasmaspheric patches are thus specific signatures of close and distorted source regions.

Item Type:	Journal Article
Subjects:	Q Science > QB Astronomy
Divisions:	Faculty of Science > Physics
Library of Congress Subject Headings (LCSH):	Atmospheric radiation, Magnetosphere
Journal or Publication Title:	Journal of Geophysical Research
Publisher:	American Geophysical Union
ISSN:	0148-0227
Date:	2011
Volume:	Vol.116
Page Range:	A07219
Identification Number:	10.1029/2011JA016476
Status:	Peer Reviewed
Publication Status:	Published
Access rights to Published version:	Restricted or Subscription Access
Funder:	Centre national d'études spatiales (France) (CNES), Science and Technology Facilities Council (Great Britain) (STFC)
References:	Aikyo, K., and T. Ondoh (1971), Propagation of nonducted VLF waves in the vicinity of the plasmapause, J. Radio Res. Lab. Jpn., 18, 153. Alfvén, H. (1968), Some properties of magnetospheric neutral surfaces, J. Geophys. Res., 73, 4379, doi:10.1029/JA073i013p04379. Angerami, J., and J. Thomas (1964), The distribution of ions and electrons in the Earth’s exosphere, J. Geophys. Res., 69, 4537, doi:10.1029/ JZ069i021p04537. Balogh, A., et al. (2001), The Cluster magnetic field investigation: Overview of in‐flight performance and initial results, Ann. Geophys., 19, 1207, doi:10.5194/angeo-19-1207-2001. Barbosa, D. D. (1982), Low‐level VLF and LF radio emissions observed at Earth and Jupiter, Rev. Geophys., 20, 316, doi:10.1029/ RG020i002p00316. Bernstein, I. B. (1958), Waves in a plasma in a magnetic field, Phys. Rev., 109, 10, doi:10.1103/PhysRev.109.10. Burton, R. K., R. L. Mc Pherron, and C. T. Russel (1975), An empirical relationship between interplanetary conditions and Dst, J. Geophys. Res., 80, 4204, doi:10.1029/JA080i031p04204. Calvert, W. (1985), DE‐1 measurements of AKR wave directions, Geophys. Res. Lett., 12, 381, doi:10.1029/GL012i006p00381. Canu, P., P. Décréau, S. Escoffier, and S. Grimald (2006), Observations of continuum radiation close to the plasmapause: Evidence for small scale sources, in Planetary Radio Emissions VI: Proceedings of the 6th International Workshop Held at Graz, Austria April 20–22, 2005, edited by H. O. Rucker, W. S. Kurth, and G. Mann, pp. 289–297, Akademie, Vienna. Carpenter, D. L. (1963), Whistler evidence of a “knee” in the magnetospheric ionization density profile, J. Geophys. Res., 68, 1675, doi:10.1029/JZ068i006p01675. Carpenter, D. L. (1970), Whistler evidence of the dynamic behavior of the duskside bulge in the plasmasphere, J. Geophys. Res., 75, 3837, doi:10.1029/JA075i019p03837. Chappell, C. R., K. K. Harris, and G. W. Sharp (1970), A study of the influence of magnetic activity on the location of the plasmapause as measured by OGO 5, J. Geophys. Res., 75, 50, doi:10.1029/JA075i001p00050. Christiansen, P. J., J. Etcheto, K. Ronmark, and L. Stenflo (1984), Upper hybrid turbulence as a source of nonthermal continuum radiation, Geophys. Res. Lett., 11, 139, doi:10.1029/GL011i002p00139. Darrouzet, F., et al. (2004), Density structures inside the plasmasphere: Cluster observations, Ann. Geophys., 22, 2577, doi:10.5194/angeo-22- 2577-2004. Darrouzet, F., et al. (2009), Plasmaspheric density structures and dynamics: Properties observed by the CLUSTER and IMAGE missions, Space Sci. Rev., 145, 55, doi:10.1007/s11214-008-9438-9 Décréau, P. M. E., et al. (1997), WHISPER, a resonance sounder and wave analyser: Performances and perspectives for the Cluster mission, Space Sci. Rev., 79, 157, doi:10.1023/A:1004931326404. Décréau, P. M. E., et al. (2001), Early results from Whisper instrument on Cluster: An overview, Ann. Geophys., 19, 1241, doi:10.5194/angeo-19- 1241-2001. Décréau, P. M. E., et al. (2004), Observation of Continuum radiations from the CLUSTER fleet: First results from direction finding, Ann. Geophys., 22, 2607, doi:10.5194/angeo-22-2607-2004. Dungey, J. W. (1961), Interplanetary magnetic field and the auroral zones, Phys. Rev. Lett., 6, 47, doi:10.1103/PhysRevLett.6.47. El‐Lemdani Mazouz, F., J. L. Rauch, P. M. E. Décréau, J. G. Trotignon, X. Vallières, F. Darrouzet, P. Canu, and X. Suraud (2009), Wave emissions at half electron gyroharmonics in the equatorial plasmasphere region: CLUSTER observations and statistics, Adv. Space Res., 43, 253, doi:10.1016/j.asr.2008.06.007. Etcheto, J., P. J. Christiansen, M. P. Gough, and J. G. Trotignon (1982), Terrestrial continuum radiation observations with GEOS‐1 and ISEE‐1, Geophys. Res. Lett., 9, 1239, doi:10.1029/GL009i011p01239. Gough, M. P. (1982), Nonthermal continuum emissions associated with electron injections: Remote plasmapause sounding, Planet. Space Sci., 30, 657, doi:10.1016/0032-0633(82)90026-5. Gough, M. P., P. J. Christiansen, G. Martelli, and E. J. Gershuny (1979), Interaction of electrostatic waves with warm electrons at the geomagnetic equator, Nature, 279, 515, doi:10.1038/279515a0. Green, J. L. (1988), Ray tracing planetary radio emissions, in Planetary Radio Emissions II: Proceedings of 2nd International Workshop Held at Graz, Austria, September 7–9, 1987, edited by H. O. Rucker, S. J. Bauer, and B. M. Pedersen, pp. 355–379, Akademie, Vienna. Green, J. L., S. Boardsen, S. F. Fung, H. Matsumoto, K. Hashimoto, R. R. Anderson, B. R. Sandel, and B. W. Reinisch (2004), Association of kilometric continuum radiation with plasmaspheric structures, J. Geophys. Res., 109, A03203, doi:10.1029/2003JA010093. Grimald, S., P. M. E. Décréau, P. Canu, A. Rochel, and X. Vallières (2008), Medium latitude sources of plasmaspheric nonthermal continuum radiations observed close to harmonics of the electron gyrofrequency, J. Geophys. Res., 113, A11216, doi:10.1029/2008JA013290. Grimald, S., C. Foullon, P. M. E. Décréau, G. Le Rouzic, X. Suraud, and X. Vallières (2009), Modulation of NTC frequencies by Pc5 ULF pulsations: Experimental test of the generation mechanism and magnetoseismology of the emitting surface, J. Geophys. Res., 114, A11211, doi:10.1029/2009JA014270. Gringauz, K. I. (1963), The structure of the ionized gas envelope of Earth from direct measurements in the U.S.S.R. of local charged particle concentrations, Planet. Space Sci., 11, 281, doi:10.1016/0032-0633(63) 90030-8. Gurnett, D. A. (1975), The Earth as a radio source: The nonthermal continuum, J. Geophys. Res., 80, 2751, doi:10.1029/JA080i019p02751. Gurnett, D. A., and L. A. Frank (1976), Continuum radiation associated with low‐energy electrons in the outer radiation zone, J. Geophys. Res., 81, 3875, doi:10.1029/JA081i022p03875. Gustafsson, G., et al. (1997), The electric field and wave experiment for the Cluster mission, Space Sci. Rev., 79, 137, doi:10.1023/A:1004975108657. Jones, D., W. Calvert, D. A. Gurnett, and R. L. Huff (1987), Observed beaming of terrestrial myriametric radiation, Nature, 328, 391, doi:10.1038/328391a0. Kasaba, Y., et al. (1998), Remote sensing of the plasmapause during substorms: Geotail observation of nonthermal continuum enhancement, J. Geophys. Res., 103, 20,389, doi:10.1029/98JA00809. Kennel, C. F., et al. (1970), VLF electric field observations in the magnetosphere, J. Geophys. Res., 75, 6136, doi:10.1029/JA075i031p06136. Kimura, I. (1966), Effects of ions on whistler mode ray tracing, Radio Sci., 1, 269. Kurth, W. S. (1992), Continuum radiation in planetary magnetospheres, in Planetary Radio Emission III: Proceedings of 3rd International Workshop Held at Graz, Austria, September 2–4, 1991, edited by H. O. Rucker, S. J. Bauer, and M. L. Kaiser, pp. 329–350, Akademie, Vienna. Kurth, W. S., D. A. Gurnett, and R. R. Anderson (1981), Escaping nonthermal continuum radiation, J. Geophys. Res., 86, 5519, doi:10.1029/ JA086iA07p05519. Loewe, C. A., and G. W. Prölss (1997), Classification and mean behavior of magnetic storms, J. Geophys. Res., 102, 14,209, doi:10.1029/ 96JA04020. Melrose, D. B. (1981), A theory of nonthermal continua in the terrestrial and Jovian magnetospheres, J. Geophys. Res., 86, 30, doi:10.1029/ JA086iA01p00030. Morgan, D. D., and D. A. Gurnett (1991), The source location and beaming of terrestrial continuum radiation, J. Geophys. Res., 96, 9595, doi:10.1029/91JA00314. Olsen, R. C., S. D. Shawhan, D. L. Gallagher, J. L. Green, C. R. Chappell, and R. R. Anderson (1987), Plasma observations at the Earth’s magnetic equator, J. Geophys. Res., 92, 2385, doi:10.1029/JA092iA03p02385. Oya, H. (1971), Conversion of electrostatic plasma wave into electromagnetic waves: Numerical calculation of the dispersion relation for all wavelengths, Radio Sci., 6, 1131, doi:10.1029/RS006i012p01131. Parks, G. K. (1991), Physics of Space Plasmas: An Introduction, Addison‐ Wesley, Redwood City, Calif. Pierrard, V., and J. F. Lemaire (2004), Development of shoulders and plumes in the frame of the interchange instability mechanism for plasmapause formation, Geophys. Res. Lett., 31, L05809, doi:10.1029/ 2003GL018919. Roelof, E. C., and D. G. Sibeck (1993), Magnetopause shape as a bivariate function of interplanetary magnetic field Bz and solar wind dynamic pressure, J. Geophys. Res., 98, 21,421, doi:10.1029/93JA02362. Rönnmark, K. (1985), Generation of magnetospheric radiation by decay of Bernstein waves, Geophys. Res. Lett., 12, 639, doi:10.1029/ GL012i010p00639. Stern, D. P. (1975), The motion of a proton in the equatorial magnetosphere, J. Geophys. Res., 80, 595, doi:10.1029/JA080i004p00595. Tsyganenko, N. A., and D. P. Stern (1996), Modeling the global magnetic field of the large‐scale Birkeland current systems, J. Geophys. Res., 101, 27,187, doi:10.1029/96JA02735. Volland, H. (1973), A semiempirical model of large‐scale magnetospheric electric fields, J. Geophys. Res., 78, 171, doi:10.1029/JA078i001p00171. Wolf, R. A. (1995), Magnetospheric configuration, in Introduction to Space Physics, edited by M. G. Kivelson and C. T. Russell, pp. 288– 329, Cambridge Univ. Press, Cambridge, U. K.
URI:	http://wrap.warwick.ac.uk/id/eprint/38668