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Lower Hybrid Drive in Solar Magnetic Reconnection Regions: Implications for Electron Acceleration and Solar Heating

Published online by Cambridge University Press:  05 March 2013

Iver H. Cairns
Iver H. Cairns*
Affiliation:
School of Physics, University of Sydney, NSW 2006, Australia; [email protected]
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Abstract

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Lower hybrid (LH) drive involves the resonant acceleration of electrons parallel to the magnetic field by lower hybrid waves, often driven by ions with ring or ring-beam distributions. Charge-exchange between hydrogen atoms and protons with relative motions perpendicular to the magnetic field leads to ring distributions of pickup ions, with concomitant perpedicular ion ‘heating’. This paper considers the combination of LH drive and charge-exchange in the outflow regions of magnetic reconnection sites in the solar chromosphere and lower corona, showing that the combined mechanism naturally predicts major perpendicular ion heating and parallel electron acceleration, and exploring the mechanism’s relevance to specific solar reconnection phenomena, heating of the solar atmosphere, and production of energetic electrons that generate solar radio emission. Although primarily qualitative, analysis shows that the mechanism has numerous attractive aspects, including perpendicular ion heating that increases linearly with ion mass, parallel electron acceleration, predicted ion and electron temperatures that span those of the chromosphere and lower corona, and parallel electron speeds spanning those for type III bursts. Applications to chromospheric explosive events and low-lying active regions, and to heating the chromosphere, appear particularly suitable. Sweeping of plasma frozen-in to chromospheric and coronal magnetic field lines across the neutral atmosphere due to motions of sub-photospheric fields represents an obvious and important generalisation of the mechanism away from reconnection sites. The requirements that the neutrals not be strongly collisionally coupled to the plasma and that sufficient neutrals are available for charge-exchange restricts the LH drive mechanism to above the photosphere but below where the corona is essentially fully ionised. LH drive may thus be important in heating the chromosphere and low corona while other heating mechanisms dominate at higher altitudes. Although attractive thus far, quantitative analyses of LH drive in these contexts are necessary before definitive conclusions are reached.

Keywords

Sun: magnetic fieldsSun: activitySun: chromospherewaves
Type
Research Article
Information
Publications of the Astronomical Society of Australia , Volume 18 , Issue 4 , 2001 , pp. 336 - 344
Copyright
Copyright © Astronomical Society of Australia 2001

References

Aschwanden, M. J., Benz, A. O., & Schwartz, R. A. 1993, ApJ, 464, 985 Google Scholar
Benz, A. O. 1987, Sol. Phys., 111, 1 Google Scholar
Benz, A. O., & Smith, D. F. 1987, Sol. Phys., 107, 299 CrossRefGoogle Scholar
Benz, A. O., Csillaghy, A., & Aschwanden, M. J. 1996, A&A, 309, 291 Google Scholar
Brueckner, G. E., & Bartoe, J.-D. F. 1983, ApJ, 272, 329 CrossRefGoogle Scholar
Cairns, I. H. 1990, J. Geophys. Res., 95, 15, 167 Google Scholar
Cairns, I. H., & Gurnett, D. A. 1991a, J. Geophys. Res., 96, 7591 Google Scholar
Cairns, I. H., & Gurnett, D. A. 1991b, J. Geophys. Res., 96, 13, 913 Google Scholar
Cairns, I. H., & Zank, G. P. 2001, in Proc. Cospar Colloquium on the Outer Heliosphere: The Next Frontiers, eds K. Scherer, H. Fichtner, E. Marsch, & H. Fahr, in pressGoogle Scholar
Cranmer, S. R. 2000, ApJ, 532, 1197 Google Scholar
Dere, K. P. 1994, Adv. Space Res., 14, 13 CrossRefGoogle Scholar
Dere, K. P., Bartoe, J.-D. F., & Brueckner, G. E. 1989, Solar Phys., 123, 41 Google Scholar
Dennis, B. R. 1985, Sol. Phys., 100, 465 CrossRefGoogle Scholar
Dulk, G. A., Steinberg, J.-L., Haong, S., & Goldman, M. V. 1987, A&A, 173, 366 Google Scholar
Fontenla, J. M., Avrett, E. H., & Loeser, R. 1990, ApJ, 355, 700 Google Scholar
Fontenla, J. M., Avrett, E. H., & Loeser, R. 1991, ApJ, 377, 712 Google Scholar
Fontenla, J. M., Avrett, E. H., & Loeser, R. 1993, ApJ, 406, 319 CrossRefGoogle Scholar
Gary, S. P. 1993, Theory of Space Plasma Microinstabilities (Cambridge: Cambridge University Press)CrossRefGoogle Scholar
Gabriel, A. H. 1971, Sol. Phys., 21, 392 Google Scholar
Harrison, R. A. 1997, Sol. Phys., 175, 467 Google Scholar
Harrison, R. A., Lang, J., Brooks, D. H., & Innes, D. E. 1999, A&A, 351, 1115 Google Scholar
Hoang, S., Dulk, G. A., & Leblanc, Y. 1994, A&A, 289, 957 Google Scholar
Holman, G. D. 1985, ApJ, 293, 584 Google Scholar
Innes, D. E., & Toth, G. 1999, Sol. Phys., 185, 127 CrossRefGoogle Scholar
Innes, D. E., Inhester, B., Axford, W. I., & Wilhelm, K. 1997a, Nature, 386, 811 Google Scholar
Innes, D. E., Brekke, P., Germott, D., & Wilhelm, K. 1997b, Sol. Phys., 175, 341 Google Scholar
Kohl, J. L., et al., 1997, Sol. Phys., 175, 613 Google Scholar
McBride, J. B., Ott, E., Boris, J. P., & Orens, J. H. 1972, Phys. Fluids, 15, 2367 Google Scholar
McClements, K. G., Bingham, R., Su, J. J., Dawson, J. M., & Spicer, D. S. 1993, ApJ, 409, 465 CrossRefGoogle Scholar
McKenzie, J. F., Banaszkiewicz, M., & Axford, W. I. 1995, A&A, 303, L45 Google Scholar
McLean, D. J., & Labrum, N. R. (eds) 1985, Solar Radiophysics (Cambridge: Cambridge University Press)Google Scholar
Melrose, D. B. 1974, Sol. Phys., 37, 353 Google Scholar
Melrose, D. B. 1980, Plasma Astrophysics, Vol. II (New York: Gordon & Breach)Google Scholar
Miller, J. A., et al. 1997, J. Geophys. Res., 102, 14, 631 Google Scholar
Omelchenko, Y. A., Sagdeev, R. A., Shapiro, V. D., & Shevchenko, V. I. 1989, Sov. J. Plasma Phys., 15, 427 Google Scholar
Parker, E. N. 1963, ApJS, 8, 177 Google Scholar
Parker, E. N. 1990, Geophys. Res. Lett., 17, 2055 Google Scholar
Papadopoulos, K. D. 1984, Radio Science, 19, 571 Google Scholar
Phan, T., et al. 2000, Nature, 404, 848 Google Scholar
Poquerusse, M. 1994, A&A, 286, 611 Google Scholar
Scudder, J. D. 1992, ApJ, 398, 299 Google Scholar
Shapiro, V. D., Bingham, R., Dawson, J. M., Dobe, Z., Kellett, B. J., & Mendis, D. A. 1998, Physica Scr., T75, 39 Google Scholar
Shklovskii, I. S. 1965, Physics of the Solar Corona (Oxford: Pergamon)Google Scholar
Spicer, D. S., Benz, A. O., & Huba, J. D. 1981, A&A, 105, 221 Google Scholar
Tandberg-Hanssen, E., & Emslie, A. G. 1988, The Physics of Solar Flares (Cambridge: Cambridge University Press)Google Scholar
Wild, J. P. 1950, Aust. J. Sci. Res., A3, 541 Google Scholar
Wu, C. S. 1996, ApJ, 472, 818 CrossRefGoogle Scholar
Wu, C. S., Li, Y., Chao, J. K., Yoon, P. H., & Lee, L. C. 1998, ApJ, 495, 951 Google Scholar
Wang, X. Y., Wu, C. S., Wang, S., Chao, J. K., Lin, Y., & Yoon, P. H. 2001, ApJ, 547, 1159 Google Scholar