World Library  


Add to Book Shelf
Flag as Inappropriate
Email this Book

The Distribution of the Ring Current: Cluster Observations : Volume 29, Issue 9 (28/09/2011)

By Zhang, Q.-h.

Click here to view

Book Id: WPLBN0003989845
Format Type: PDF Article :
File Size: Pages 8
Reproduction Date: 2015

Title: The Distribution of the Ring Current: Cluster Observations : Volume 29, Issue 9 (28/09/2011)  
Author: Zhang, Q.-h.
Volume: Vol. 29, Issue 9
Language: English
Subject: Science, Annales, Geophysicae
Collections: Periodicals: Journal and Magazine Collection (Contemporary), Copernicus GmbH
Historic
Publication Date:
2011
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

Citation

APA MLA Chicago

Kamide, Y., Hu, H., Zhang, Q., Woodfield, E. E., Liu, R., Holme, R.,...Liu, S. (2011). The Distribution of the Ring Current: Cluster Observations : Volume 29, Issue 9 (28/09/2011). Retrieved from http://www.ebooklibrary.org/


Description
Description: SOA Key Laboratory for Polar Science, Polar Research Institute of China, Shanghai, China. Extending previous studies, a full-circle investigation of the ring current has been made using Cluster 4-spacecraft observations near perigee, at times when the Cluster array had relatively small separations and nearly regular tetrahedral configurations, and when the Dst index was greater than −30 nT (non-storm conditions). These observations result in direct estimations of the near equatorial current density at all magnetic local times (MLT) for the first time and with sufficient accuracy, for the following observations. The results confirm that the ring current flows westward and show that the in situ average measured current density (sampled in the radial range accessed by Cluster ~4–4.5 RE) is asymmetric in MLT, ranging from 9 to 27 nA m−2. The direction of current is shown to be very well ordered for the whole range of MLT. Both of these results are in line with previous studies on partial ring extent. The magnitude of the current density, however, reveals a distinct asymmetry: growing from 10 to 27 nA m−2 as azimuth reduces from about 12:00 MLT to 03:00 and falling from 20 to 10 nA m−2 less steadily as azimuth reduces from 24:00 to 12:00 MLT. This result has not been reported before and we suggest it could reflect a number of effects. Firstly, we argue it is consistent with the operation of region-2 field aligned-currents (FACs), which are expected to flow upward into the ring current around 09:00 MLT and downward out of the ring current around 14:00 MLT. Secondly, we note that it is also consistent with a possible asymmetry in the radial distribution profile of current density (resulting in higher peak at ~4–4.5 RE). We note that part of the enhanced current could reflect an increase in the mean AE activity (during the periods in which Cluster samples those MLT).

Summary
The distribution of the ring current: Cluster observations

Excerpt
Balogh, A., Carr, C. M., Acuña, M. H., Dunlop, M. W., Beek, T. J., Brown, P., Fornacon, K.-H., Georgescu, E., Glassmeier, K.-H., Harris, J., Musmann, G., Oddy, T., and Schwingenschuh, K.: The Cluster Magnetic Field Investigation: overview of in-flight performance and initial results, Ann. Geophys., 19, 1207–1217, doi:10.5194/angeo-19-1207-2001, 2001.; Cowley, S. W. H. and Lockwood, M.: Excitation and decay of solar-wind driven flows in the magnetosphere-ionosphere system, Ann. Geophys., 10, 103–115, 1992.; Daglis, I. A., Thorne, R. M., Baumjohann, W., and Orsini, S.: The terrestrial ring current: Origin, formation, and decay, Rev. Geophys., 37, 407–438, 1999.; De Michelis, P., Daglis, I. A., and Consolini, G.: An average image of proton plasma pressure and of current systems in the equatorial plane derived from AMPTE/CCE-CHEM measurements, J. Geophys. Res., 104, 28615–28624, 1999.; Dunlop, M. W., Southwood, D. J., Glassmeier, K.-H., and Neubauer, F. M.: Analysis of multipoint magnetometer data, Adv. Space Res., 8, 273–277, 1988.; Dunlop, M. W., Balogh, A., Glassmeier, K.-H., and Robert, P.: Four-point Cluster application of magnetic field analysis tools: The Curlometer, J. Geophys. Res., 107, 1384–1387, 2002.; Escoubet, C. P., Fehringer, M., and Goldstein, M.: Introduction: The Cluster mission, Ann. Geophys., 19, 1197–1200, doi:10.5194/angeo-19-1197-2001, 2001.; Iijima, T., Potemra, T., and Zanetti, L.: Large�]Scale Characteristics of Magnetospheric Equatorial Currents, J. Geophys. Res., 95, 991–999, 1990.; Lui, A. and Hamilton, D.: Radial Profiles of Quiet Time Magnetospheric Parameters, J. Geophys. Res., 97, 19325–19332, 1992.; Jorgensen, A. M., Spence, H. E., Hughes, W. J., and Singer, H. J.: A statistical study of the global structure of the ring current, J. Geophys. Res., 109, A12204, doi:10.1029/2003JA010090, 2004.; Le, G., Russell, C. T., and Takahashi, K.: Morphology of the ring current derived from magnetic field observations, Ann. Geophys., 22, 1267–1295, doi:10.5194/angeo-22-1267-2004, 2004.; Rème, H., Aoustin, C., Bosqued, J. M., Dandouras, I., Lavraud, B., Sauvaud, J. A., Barthe, A., Bouyssou, J., Camus, Th., Coeur-Joly, O., Cros, A., Cuvilo, J., Ducay, F., Garbarowitz, Y., Medale, J. L., Penou, E., Perrier, H., Romefort, D., Rouzaud, J., Vallat, C., Alcaydé, D., Jacquey, C., Mazelle, C., d'Uston, C., Möbius, E., Kistler, L. M., Crocker, K., Granoff, M., Mouikis, C., Popecki, M., Vosbury, M., Klecker, B., Hovestadt, D., Kucharek, H., Kuenneth, E., Paschmann, G., Scholer, M., Sckopke, N., Seidenschwang, E., Carlson, C. W., Curtis, D. W., Ingraham, C., Lin, R. P., McFadden, J. P., Parks, G. K., Phan, T., Formisano, V., Amata, E., Bavassano-Cattaneo, M. B., Baldetti, P., Bruno, R., Chionchio, G., Di Lellis, A., Marcucci, M. F., Pallocchia, G., Korth, A., Daly, P. W., Graeve, B., Rosenbauer, H., Vasyliunas, V., McCarthy, M., Wilber, M., Eliasson, L., Lundin, R., Olsen, S., Shelley, E. G., Fuselier, S., Ghielmetti, A. G., Lennartsson, W., Escoubet, C. P., Balsiger, H., Friedel, R., Cao, J.-B., Kovrazhkin, R. A., Papamastorakis, I., Pellat, R., Scudder, J., and Sonnerup, B.: First multispacecraft ion measurements in and near the Earth's magnetosphere with the identical Cluster ion spectrometry (CIS) experiment, Ann. Geophys., 19, 1303–1354, doi:10.5194/angeo-19-1303-2001, 2001.; Robert, P., Dunlop, M. W., Roux, A., and Chanteur, G.: Accuracy of current density determination, in Analysis Methods for Multispacecraft Data, ISSI Sci. Rep., SR-001, 395–418, 1998.; Singer, S. F.: A new model of magnetic storms and aurorae, Trans. AGU, 38, 175–190, 1957.; Tsyganenko, N. A. and Stern, D. P.: M


 

Click To View

Additional Books


  • Multi-frequency Observations of E-region... (by )
  • Properties of a Cusp Diamagnetic Cavity ... (by )
  • Numerical Study of the Middle Adriatic C... (by )
  • Seasonal Cycle of Cloud Cover Analyzed U... (by )
  • Modelling the Solar Wind Interaction wit... (by )
  • Interhemispheric Observations of the Ion... (by )
  • Eastward Sub-auroral Ion Drifts or Asaid... (by )
  • Influence of the Ionosphere on the Altit... (by )
  • Solar and Magnetospheric Forcing of the ... (by )
  • Modulation of Radio Frequency Signals by... (by )
  • Magnetopause Surface Oscillation Frequen... (by )
  • Velocity of Auroral Arcs Drifting Equato... (by )
Scroll Left
Scroll Right

 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.