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Dominance of toroidal oscillations in dawn/dusk sectors: A consequence of solar wind pressure variation
Earth, Planets and Space volume 55, pages 93–104 (2003)
Abstract
The pressure variations in the solar wind produce the oscillations in surface currents at the magnetopause boundary in order to nullify the pressure imbalance. These currents introduce compressional variations in the magnetic field within the magnetosphere. The response of transverse field line oscillations to such changes in the magnetic field has been brought out in perfectly reflecting ionospheric conditions. The analysis clearly shows that the fundamental toroidal modes are dominant in the dawn and the dusk sectors as revealed by the statistical studies of pulsations observed by the satellite AMPTE/CCE (Anderson et al., 1990). It is traditionally believed that such oscillations are mainly driven by Kelvin-Helmholtz (K-H) instability (Anderson et al., 1990). Our analysis shows that the dominance of fundamental toroidal modes in the dawn and dusk sectors can also be explained in terms of response to impressed pressure impulses without invoking K-H instability. The analysis also shows that poloidal modes do not exhibit any longitudinal structures. These results are consistent with the observations (Anderson et al., 1990).
References
Allan, W., S. P. White, and E. M. Poulter, Magnetospheric coupling of hydromagnetic waves—initial results, Geophys. Res. Let., 12, 287, 1985.
Allan, W., E. M. Poulter, and S.P. White, Magnetospheric wave coupling in the magnetosphere-plasmapause effects on impulse-excited resonances, Planet. Sp. Sci., 34, 1189, 1986.
Anderson, B. J., M. J. Engebretson, S. P. Rounds, L. J. Zanetti, and T. A. Potemra, A statistical study of Pc3-5 pulsations observed by the AMPTE/CCE magnetic fields experiment 1. Occurrence distributions, J. Geophys. Res., 95, 10,495, 1990.
Baumjohann, W., H. Junginger, G. Haerendel, and O. H. Bauer, Resonant Alfvén waves excited by a sudden impulse, J. Geophys. Res., 89, 2765, 1984.
Chen, L. and A. Hasegawa, A theory of long-period magnetic pulsations-2. impulse excitation of surface eigenmode, J. Geophys. Res., 79, 1033, 1974.
Cummings, W. D., R. J. O’Sullivan, and P. J. Coleman, Standing Alfvén waves in the magnetosphere, J. Geophys. Res., 74, 778, 1969.
Dudley, D. G., Mathematical Foundations for Electromagnetic Theory, 99 pp., Institute of Electrical and Electronics Engineers, Inc., Newyork, 1994.
Dungey, J. W., Electrodynamics of the outer atmospheres, Rep., 69, Ions. Res. Lab. Pa. State Univ., University Park, 1954.
Farrugia, C. J., M. P. Freeman, S. W. H. Cowley, D. J. Southwood, M. Lockwood, and A. Etemadi, Planet. Sp. Sci, 37, 589, 1989.
Fujita, S. and V. L. Patel, Eigenmode analysis of coupled magnetohydrodynamic oscillations in the magnetosphere, J. Geophys. Res., 97, 13,771, 1992.
Fujita, S., M. Itonaga, and H. Nakata, Relationship between the Pi2 pulsations and the localized impulsive current associated with the current disruption in the magnetosphere, Earth Planets Space, 52, 267, 2000.
Fujita, S., T. Mizuta, M. Itonaga, A. Yoshikawa, and H. Nakata, Propagation properties of transient MHD impulses in the magnetosphere-ionosphere system: The 2D model of the Pi2 pulsations, Geophys. Res. Let., 28, 2161, 2001.
Itonaga, M., A. Yoshikawa, and K. Yumoto, One-dimensional transient response of the inner magnetosphere at the magnetic equator, 2. Analysis of waveform, J. Geomag. Geoelectr., 49, 49, 1997.
Lee, D.H., Dynamics of MHD wave propagation in the low-latitude magnetosphere, J. Geophys. Res., 101, 15,371, 1996.
Leonovich, A. S. and V. A. Mazur, Theory of transverse small-scale standing Alfvén waves in an axially symmetric magnetosphere, Planet. Sp. Sci, 41, 697, 1993.
Leonovich, A. S. and V. A. Mazur, A model equation for monochromatic standing Alfvén waves in the axially symmetric magnetosphere, J. Geophys. Res., 102, 11,443, 1997.
Mead, G. D., Deformation of the geomagnetic field by the solar wind, J. Geophys. Res., 69, 1181, 1964.
Nagata, T, S. Kokubun, and T. Ijima, Geomagnetically conjugate relationships of giant pulsations at Syowa Base, Antarctica, and Reykjavik, Iceland, J. Geophys. Res., 68, 4621, 1963.
Nakata, H., S. Fujita, A. Yoshikawa, M. Itonaga, and K. Yumoto, Ground magnetic perturbations associated with the standing toroidal mode oscillations in the magnetosphere-ionosphere system, Earth Planets Space, 52, 601, 2000.
Newton, R. S., D. J. Southwood, and W. J. Hughes, Damping of geomagnetic pulsations by the ionosphere, Planet. Sp. Sci., 26, 201, 1978.
Schulz, M. and L. J. Lanzerotti, Particle diffusion in radiation belts, Springer-Verlag, Berlin Heidelberg Newyork, 1974.
Sibeck, D. G., W. Baumjohann, and R. E. Lopez, Solar wind dynamic pressure variations and transient magnetospheric signatures, Geophys. Res. Let., 16, 13, 1989.
Singer, H. J., D. J. Southwood, R. J. Walker, and M. G. Kivelson, Alfvén wave resonances in a realistic magnetospheric magnetic field geometry, J. Geophys. Res., 86, 4589, 1981.
Sinha, A. K. and R. Rajaram, An analytic approach to toroidal eigen mode, J. Geophys. Res., 102, 17,649, 1997.
Southwood, D. J. and W. J. Hughes, Theory of hydromagnetic waves in the magnetosphere, Space Sci. Rev., 35, 301, 1983.
Southwood, D. J. and M. G. Kivelson, The hydromagnetic response of the magnetospheric cavity to changes in solar wind pressure, J. Geophys. Res., 95, 2301, 1990.
Sugiura, M., Evidence of low frequency hydromagnetic waves in the exosphere, J. Geophys. Res., 66, 4087, 1961.
Walker, A. D. M., Excitation of magnetohydrodynamic cavities in the magnetosphere, J. Atmos. Ter. Phys., 60, 1279, 1998.
Walker, A. D. M., Coupling between waveguide modes and field line resonances, J. Atmos. Ter Phys., 62, 799, 2000.
Yoshikawa, A. and M. Itonaga, Reflection of shear Alfvén waves at the ionosphere and the divergent Hall current, Geophys. Res. Let., 23, 101, 1996.
Yoshikawa, A., M. Itonaga, S. Fujita, H. Nakata, and K. Yumoto, Eigenmode analysis of field line oscillations interacting with the ionosphere-atmosphere-solid earth electromagnetic coupled system, J. Geophys. Res., 104, 28,437, 1999.
Zhu, X. M. and M. G. Kivelson, Global mode ULF oscillations in a magnetosphere with a monochromatic Alfvén velocity profile, J. Geophys. Res., 94, 1479, 1989.
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Sinha, A.K., Rajaram, R. Dominance of toroidal oscillations in dawn/dusk sectors: A consequence of solar wind pressure variation. Earth Planet Sp 55, 93–104 (2003). https://doi.org/10.1186/BF03351736
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DOI: https://doi.org/10.1186/BF03351736
Keywords
- Solar Wind
- Solar Wind Dynamic Pressure
- Ionospheric Conductivity
- Toroidal Mode
- Driving Period