The role of heavy ions in the nonlinear modification of magnetospheric plasma under the influence of the ULF waves
Category: 15-2
UDC 550.344
A.K. Nekrasov, F.Z. Feygin
Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia
Abstract. A relationship for the ponderomotive force in realistic multi-component magnetospheric plasma containing several species heavy ions is given. The nonlinear stationary balance equation taking into account electromagnetic, gravitational, and centrifugal forces in the plasma consisting of electrons, protons and two species of heavy ions (He+ and O+) is obtained. The equation of force balance is solved numerically to obtain the nonlinear distribution of hydrogen ions (H+) along the magnetic field line in the presence of heavy ions. It has been shown that for frequencies less than the oxygen gyrofrequency at the equator a nonlinear plasma density perturbation has a maximum in the vicinity of the equator due to the action of ponderomotive and centrifugal forces. Comparison of the nonlinear density distributions in dipolar and non-dipolar dayside magnetosphere is provided. The results show that the presence of heavy ions causes a decrease of the proton density in the equator vicinity.
Keywords: magnetosphere, plasma, ponderomotive force, heavy ions.
References
Allan W. Ponderomotive mass transport in the magnetosphere, J. Geophys. Res., 1992, vol. 97, pp. 8483–8493.
Allan W., Manuel J.R., Ponderomotive effects in magnetospheric hydromagnetic waves, Ann. Geophys., 1996, vol. 14, pp. 893–905.
Antonova A.E. and Shabanskii V.P., The magnetic field structure at large distances from the Earth, Geomagn. Aeron., 1968, vol. 8, pp. 801–805
Antonova A.E., Shabanskii V.P., and Hedgcok, P.S., A comparison of the magnetic field model empirical model, based on the HEOS-1, 2 data, with the analytical two-dipole model of the magnetosphere, Geomagn. Aeron., 1983, vol. 23, pp. 697–699.
Carpenter D.L. and Anderson R.R., An ISEE/ whistler model of equatorial electron density in the magnetosphere, J. Geophys. Res., 1992, vol. 97, pp. 1097–1108.
Chappel C.R., Detached plasma regions in the magnetosphere, J. Geophys. Res., 1974, vol. 79, pp. 1861–1870.
Denton R.E., Takahashi K., Galkin I.A., Nsumei P.A., Huang X., and Reinisch B.W., Anderson R.R., Sleeper M.K., Hughes W.J., Distribution of density along magnetospheric field lines, J. Geophys. Res., 2006, vol. 111, pp. A04213. doi: 10.1029/2005JA011414.
Fraser B.J. and McPherron R.L,. Pc1-2 magnetic pulsation spectra and heavy ion effects at synchronous orbit: ATS 6 results, J. Geophys. Res., 1982, vol. 87, pp. 4560–4566,
Fraser B.J., Samson J.C., Hu Y.D., McPherron R.L., and Russel C.T. Electromagnetic ion cyclotron waves observed near the oxygen cyclotron frequency by ISEE 1 and 2, J. Geophys. Res., 1992, vol. 97, pp. 3063–3074.
Guglielmi A.V., Pokhotelov O.A., Stenflo L., and Shukla P.K. Modification of the magnetospheric plasma due to ponderomotive forces, Astrophys. Space Sci., 1993, vol. 200, pp. 91–96.
Guglielmi A.V. and Pokhotelov O.A. Nonlinear problems of physics of the geomagnetic pulsations, Space Sci. Rev., 1994, vol. 65, pp. 5–57.
Guglielmi A.V., Pokhotelov O.A., Feygin F.Z., Kurchashov Yu.P., McKenzie J.F., Shukla P.K., Stenflo L., and Potapov A.S. Ponderomotive wave forces in longitudinal MHD waveguides ,J. Geophys. Res., 1995, vol. 100, pp. 7997–8002.
Kozyra J.U., Cravens T.E., Nagy A.F., and Fonthim E.G. Effects of energetic heavy ions on electromagnetic ion cyclotron wave generation in plasmapause region, J. Geophys. Res., 1984, vol. 89, pp. 2217–2233.
Lemaire J. Plasma distribution models in a rotating magnetic dipole and refilling of plasmaspheric flux tubes, Phys. Fluids B., 1989, vol. 1, pp. 1519–1525.
Mauk B.N., McIlwain C.E., and McPherron R.L. Helium cyclotron resonance within the. Earth's magnetosphere, Geophys. Res. Lett., 1981, vol. 8, pp. 103–106.
Nekrasov A.K. and Feygin F.Z. Ponderomotive action of ULF pulsations in the magnetospheric plasma, Phys. Scr., 2005, vol. 71, pp. 310–313.
Nekrasov A.K. and Feygin F.Z. Nonlinear plasma density modification by the ponderomotive force of ULF pulsations at the dayside magnetosphere, Astrophys. Space Sci., 2012, vol. 341, pp. 225–230.
Nekrasov A.K. and Feygin F.Z. Ponderomotive modification of multicomponent magnetospheric plasma due to electromagnetic ion cyclotron waves, Astrophys. Space Sci., 2013, vol. 346, pp. 203–212.
Persoon A.M., Gurnett D.A., Santolik O., Kurth W.S., Faden J.B., Groene J.B., Lewis G.R., Coates A.J., Wilson R.J., Tokar R.L., Wahlund J.-E., and Moncuquet M., A diffusive equilibrium model for the plasma density in Saturn’s magnetosphere, J. Geophys. Res., 2009, vol. 114. A04211, doi:10.1029/2008JA013912.
Pokhotelov O.A., Feygin F.Z., Stenflo L., and Shukla P.K., Density profile modifications by electromagnetic ion-cyclotron wave pressures near the dayside magnetospheric boundary, J. Geophys. Res., 1996, vol. 101, pp. 10.827–10.833.
Witt E.F., Hudson M.K., Li X., Roth I., and Temerin M., Ponderomotive effects on distribution of O+ ions in the auroral zone, J. Geophys. Res., 1995, vol. 100, pp. 12151–12162.
Young D.T., Perraut S., Roux A., Villedary C., Gendrin R., Korth A., Kremser G., and Jones D., Wave-particle interactions near WHe+ observed on GEOS 1 and 2. 1. Propagation of ion cyclotron waves in He+-rich plasma, J. Geophys. Res., 1981, vol. 86, pp. 6755–6772.