World Library  


Add to Book Shelf
Flag as Inappropriate
Email this Book

Polar Cap Arcs from the Magnetosphere to the Ionosphere: Kinetic Modelling and Observations by Cluster and Timed : Volume 30, Issue 2 (03/02/2012)

By Maggiolo, R.

Click here to view

Book Id: WPLBN0004002119
Format Type: PDF Article :
File Size: Pages 20
Reproduction Date: 2015

Title: Polar Cap Arcs from the Magnetosphere to the Ionosphere: Kinetic Modelling and Observations by Cluster and Timed : Volume 30, Issue 2 (03/02/2012)  
Author: Maggiolo, R.
Volume: Vol. 30, Issue 2
Language: English
Subject: Science, Annales, Geophysicae
Collections: Periodicals: Journal and Magazine Collection (Contemporary), Copernicus GmbH
Historic
Publication Date:
2012
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

Citation

APA MLA Chicago

Zhang, Y., Lointier, G., Wedlund, C. S., Trotignon, J., Fontaine, D., Maggiolo, R., & Echim, M. (2012). Polar Cap Arcs from the Magnetosphere to the Ionosphere: Kinetic Modelling and Observations by Cluster and Timed : Volume 30, Issue 2 (03/02/2012). Retrieved from http://members.worldlibrary.net/


Description
Description: Belgian Institute for Space Aeronomy (BIRA-IASB), Space Plasma, Brussels, Belgium. On 1 April 2004 the GUVI imager onboard the TIMED spacecraft spots an isolated and elongated polar cap arc. About 20 min later, the Cluster satellites detect an isolated upflowing ion beam above the polar cap. Cluster observations show that the ions are accelerated upward by a quasi-stationary electric field. The field-aligned potential drop is estimated to about 700 V and the upflowing ions are accompanied by a tenuous population of isotropic protons with a temperature of about 500 eV.

The magnetic footpoints of the ion outflows observed by Cluster are situated in the prolongation of the polar cap arc observed by TIMED GUVI. The upflowing ion beam and the polar cap arc may be different signatures of the same phenomenon, as suggested by a recent statistical study of polar cap ion beams using Cluster data.

We use Cluster observations at high altitude as input to a quasi-stationary magnetosphere-ionosphere (MI) coupling model. Using a Knight-type current-voltage relationship and the current continuity at the topside ionosphere, the model computes the energy spectrum of precipitating electrons at the top of the ionosphere corresponding to the generator electric field observed by Cluster. The MI coupling model provides a field-aligned potential drop in agreement with Cluster observations of upflowing ions and a spatial scale of the polar cap arc consistent with the optical observations by TIMED. The computed energy spectrum of the precipitating electrons is used as input to the Trans4 ionospheric transport code. This 1-D model, based on Boltzmann's kinetic formalism, takes into account ionospheric processes such as photoionization and electron/proton precipitation, and computes the optical and UV emissions due to precipitating electrons. The emission rates provided by the Trans4 code are compared to the optical observations by TIMED. They are similar in size and intensity. Data and modelling results are consistent with the scenario of quasi-static acceleration of electrons that generate a polar cap arc as they precipitate in the ionosphere. The detailed observations of the acceleration region by Cluster and the large scale image of the polar cap arc provided by TIMED are two different features of the same phenomenon. Combined together, they bring new light on the configuration of the high-latitude magnetosphere during prolonged periods of Northward IMF. Possible implications of the modelling results for optical observations of polar cap arcs are also discussed.


Summary
Polar cap arcs from the magnetosphere to the ionosphere: kinetic modelling and observations by Cluster and TIMED

Excerpt
Ajello, J. M. and Shemansky, D. E.: A reexamination of important N2 cross sections by electron impact with application to the dayglow – The Lyman-Birge-Hopfield band system and N I (1199.99 nm), J. Geophys. Res., 90, 9845–9861, 1985.; Anderson Jr., D. E., Meier, R. R., Feldman, P. D., and Gentieu, E. P.: The UV dayglow 3, OI emissions at 989, 1027, 1152, 1304, and 1356A, Geophys. Res. Lett., 7, 1057–1060, 1980.; Avakyan, S. V. (Ed.): Collision processes and excitation of UV emission from planetary atmospheric gases: a handbook of cross sections, Gordon and Breach Science Publishers, Amsterdam, The Netherlands, 1998.; 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.; Baumjohann, W. and Treumann, R. A.: Basic space plasma physics, London: Imperial College Press, 1997.; Berg, G. A., Kelley, M. C., Mendillo, M., Doe, R., Vickrey, J., Kletzing, C., Primdahl, F., and Baker, K. D.: Formation and eruption of Sun-aligned arcs at the polar cap-auroral oval boundary, J. Geophys. Res., 99, 17577–17589, 1994.; Bonnell, J., Elphic, R. C., Palfery, S., Strangeway, R. J., Peterson, W. K., Klumpar, D., Carlson, C. W., Ergun, R. E., and McFadden, J. P.: Observations of polar cap arcs on FAST, J. Geophys. Res., 104, 12669–12682, 1999.; Burke, W. J., Hardy, D. A., Rich, F. J., Gussenhoven, M. S., and Kelley, M. C.: Electric and magnetic field characteristics of discrete arcs in the polar cap, J. Geophys. Res., 87, 2431–2443, 1982.; Carlson, H. C. and Cowley, S. W. H.: Accelerated polar rain electrons as the source of Sun-aligned arcs in the polar cap during northward interplanetary magnetic field conditions, J. Geophys. Res., 110, A05302.1–A05302.10, 2005.; Carlson, H. C., Weber, E. J., Heelis, R. A., and Sharber, J. R.: Coherent mesoscale convection patterns during northward interplanetary magnetic field, J. Geophys. Res., 93, 14501–14514, 1988; Chiu, Y. T. and Schulz, M.: Self-consistent particle and parallel electrostatic field distributions in the magnetosphericionospheric auroral region, J. Geophys. Res., 83, 629–642, 1978.; Christensen, A. B., Paxton, L. J., Avery, S., Craven, J., Crowley, G., Humm, D. C., Kil, H., Meier, R. R., Meng, C.-I., Morrison, D., Ogorzalek, B. S., Straus, P., Strickland, D. J., Swenson, R. M., Walterscheid, R. L., Wolven, B., and Zhang, Y.: Initial observations with the Global Ultraviolet Imager (GUVI) in the NASA TIMED satellite mission, J. Geophys. Res., 108, SIA 16-1, 2003.; Décréau, P. M. E., Fergeau, P., Krasnoselskikh, V., Le Guirriec, E., Lévêque, M., Martin, Ph., Randriamboarison, O., Rauch, J. L., Sené, F. X., Séran, H. C., Trotignon, J. G., Canu, P., Cornilleau, N., de Féraudy, H., Alleyne, H., Yearby, K., M�gensen, P. B., Gustafsson, G., André, M., Gurnett, D. C., Darrouzet, F., Lemaire, J., Harvey, C. C., Travnicek, P., and Whisper experimenters: Early results from the Whisper instrument on Cluster: an overview, Ann. Geophys., 19, 1241–1258, doi:10.5194/angeo-19-1241-2001, 2001.; De Keyser, J. and Echim, M.: Auroral and sub-auroral phenomena: an electrostatic picture, Ann. Geophys., 28, 633–650, doi:10.5194/angeo-28-633-2010, 2010.; De Keyser, J. and Roth, M.: Equilibrium conditions and magnetic field rotation at the tangential discontinuity magnetopause, J. Geophys. Res., 103, 6653–6662, 1998.; De Keyser, J., Maggiolo, R., and Echim, M.: Monopolar and bipolar auroral electric fields and their effects, Ann. Geophys., 28, 2027–2046,

 

Click To View

Additional Books


  • A Method to Identify Aperiodic Disturban... (by )
  • Correlation Length of Magnetosheath Fluc... (by )
  • The Shape of the Sq Current System : Vol... (by )
  • Validation of Modis Derived Aerosol Opti... (by )
  • Common Volume Coherent and Incoherent Sc... (by )
  • Substorms and Polar Cap Convection: the ... (by )
  • Magnetopause Displacements: the Possible... (by )
  • On the Size Distribution of Ice-supersat... (by )
  • Role of Mixed Precipitating Cloud System... (by )
  • Large Aerosol Optical Depths Observed at... (by )
  • Multi-frequency Observations of E-region... (by )
Scroll Left
Scroll Right

 



Copyright © World Library Foundation. All rights reserved. eBooks from World 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.