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Energetic particle precipitation in the Brazilian geomagnetic anomaly during the “Bastille Day storm” of July 2000

Abstract

Ionospheric absorption associated with a great geomagnetic storm on July 15–16, 2000 (the “Bastille Day storm”) was observed in the Brazilian geomagnetic anomaly using a two-dimensional 4 × 4 imaging riometer (IRIS). In the afternoon of July 15, weak absorption (≈0.2 dB) was observed during the initial phase of the storm; large spatial-scale absorption exceeded the IRIS field of view (330×330 km). During the sharp magnetic decrease in the main phase of the storm, absorption was intensified (<0.5 dB) in the evening, showing a sheet structure with ≈150 km latitudinal width and >330 km longitudinal elongation. Subsequently, absorption was intensified (≈1 dB), having a small spatial-scale (≈150 km) in the background sheet structure and a pronounced westward drift (≈570 m s-1). In association with large magnetic fluctuations in the Bz component of the interplanetary magnetic field (IMF), the ground magnetic variation in the night sector showed large positive swings during the initial to main phases of the storm. With the subsequent southward turning of the IMF Bz, the ground magnetic variation in the evening sector showed rapid storm development. Particle fluxes measured by a geosynchronous satellite (L =≈6.6) demonstrated large enhancements of low-energy protons (50–400 keV) and probably electrons (50–225 keV) during the storm’s initial phase. Particle fluxes from the low-altitude NOAA satellite (≈870 km) indicated the invasion of low-energy particles into the region of L < 2 during the main phase of the storm. These results indicate that low-energy particles injected into the outer radiation belt in association with frequent and strong substorm occurrences, were transported into the inner radiation belt through direct convective access by the storm-induced electric fields during the storm’s development. These particles then precipitated into the ionosphere over the Brazilian geomagnetic anomaly. Notably, the most intense absorption could be dominantly caused by proton precipitation with energies of ≈40 keV. Key words: Bastille Day storm, Brazilian geomagnetic anomaly, energetic particle precipitation, imaging riometer.

References

  • Abdu, M. A., S. S. Degaonkar, and K. R. Ramanathan, Attenuation of galactic radio noise at 25 Mhz and 21.3 Mhz in the ionosphere over Ahmedabad during 1957–1964, J. Geophys. Res., 72(5), 1547–1554, 1967.

    Article  Google Scholar 

  • Abdu, M. A., S. Ananthakrishnan, E. F. Coutinho, B. A. Krishnan, and E. M. Da S. Reis, Azimuthal drift and precipitation of electrons into the South Atlantic geomagnetic anomaly during an SC magnetic storm, J. Geophys. Res., 78(25), 5830–5836, 1973.

    Article  Google Scholar 

  • Abdu, M. A., I. S. Batista, R. Piazza, and O. Massambani, Magnetic storm associated enhanced particle precipitation in the South Atlantic anomaly: Evidence from VLF phase measurements, J. Geophys. Res., 86(A9), 7533–7542, 1981.

    Article  Google Scholar 

  • Abel, B. and R. M. Thorne, Modeling energetic electron precipitation near the South Atlantic anomaly, J. Geophys. Res., 104(A4), 7037–7044, 1999.

    Article  Google Scholar 

  • Badhwar, G. D., Drift rate of the South Atlantic anomaly, J. Geophys. Res., 102, 2343–2349, 1997.

    Article  Google Scholar 

  • Basu, S., Su Basu, K. M. Gloves, H.-C. Yeh, S.-Y. Su, R. J. Rich, P. J. Sultan, and M. J. Keskinen, Response of the equatorial ionosphere in the South Atlantic region to the great magnetic storm of July 15, 2000, Geophys. Res. Lett., 28(18), 3577–3580, 2001.

    Article  Google Scholar 

  • Batista, L. S. and M. A. Abdu, Magnetic storm associated with delayed sporadic E enhancements in the Brazilian geomagnetic anomaly, J. Geophys. Res., 82(29), 4777–4783, 1977.

    Article  Google Scholar 

  • Chen, M., M. Schulz, and L. R. Lyons, Modeling of ring current formation and decay: A review, Magnetic Storms, Geophysical Monograph, 98, pp. 173–186, AGU, Washington, D.C., 1997.

    Google Scholar 

  • Datlowe, D. W. and W. L. Imhof, Seasonal variations of energetic electron precipitation by cyclotron resonance with VLF waves from a groundbased transmitter, Radio Science, 28, 705–714, 1993.

    Article  Google Scholar 

  • Fälthammer, C. G., Motion of charged particles in the magnetosphere, in Cosmic Geophysics, edited by A. Egeland et al., p. 121, Universitiesforlaget, Oslo, 1973.

  • Gledhill, J. A., Aeronomic effects of the South Atlantic anomaly, Rev. Geophys. Space Phys., 14(2), 173–187, 1976.

    Article  Google Scholar 

  • Gonzalez, W. D., S. L. G. Dutra, and O. Pinto, Jr., Middle atmospheric electrodynamic modification by particle precipitation at the South Atlantic Magnetic Anomaly, J. Atmos. Terr. Phys., 49(4), 377–383, 1987.

    Article  Google Scholar 

  • Gough, M. P. and M. A. Abdu, Particle precipitation in the South Atlantic anomaly deduced from VLF propagation path measurements, J. Atmos. Terr. Phys., 37, 1379–1383, 1975.

    Article  Google Scholar 

  • Greenspan, M. E., G. M. Mason, and J. E. Mazur, Low-altitude equatorial ions: A new look with SAMPEX, J. Geophys. Res., 104(A9), 19,911–19,922, 1999.

    Article  Google Scholar 

  • Jayanthi, U. B., M. G. Pereira, I. M. Martin, Y. Stozkov, F. D’Amico, and T. Villela, Electron precipitation associated with geomagnetic activity: Balloon observation of X ray flux in South Atlantic anomaly, J. Geophys. Res., 102(A11), 24,069–24,073, 1997.

    Article  Google Scholar 

  • Kohno, T., K. Munakata, K. Nagata, H. Murakami, A. Nakamoto, N. Hasebe, J. Kikuchi, and T. Doke, Intensity maps of MeV electrons and protons below the radiation belt, Planet. Space Sci., 38(4), 483–490, 1990.

    Article  Google Scholar 

  • Lühr, H., A. Aylward, S. C. Bucher, A. Pajunpaa, K. Pajunpaa, T. Holmboe, and S.M. Zalewski, Westward moving dynamic substorm features observed with IMAGE magnetometer network and other ground-based instruments, Ann. Geophys., 16, 425–440, 1998.

    Article  Google Scholar 

  • Lyons, L. R. and M. Schulz, Access of energetic particles to storm time ring current through enhanced radial “diffusion”, J. Geophys. Res., 94(A5), 5491–5496, 1989.

    Article  Google Scholar 

  • Lyons, L. R. and D. J. Williams, A source for the geomagnetic storm main phase ring current, J. Geophys. Res., 85(A2), 523–530, 1980.

    Article  Google Scholar 

  • Nagata, K., T. Khono, H. Murakami, A. Nakamoto, N. Hasebe, T. Takenaka, J. Kikuchi, and T. Doke, OHZORA high energy particle observations, J. Geomag. Geoelectr., 37, 329–345, 1

    Article  Google Scholar 

  • Nishino, M., Y. Tanaka, T. Oguti, H. Yamagishi, and J. A. Holtet, Initial observation results with imaging riometer at Ny Alesund (L = 16), Proc. NIPR Symposium on Upper Atmosphere Physics, 6, 47–60, 1

    Google Scholar 

  • Nishino, M., K. Makita, K. Yumoto, F. Rodrigues, N. J. Schuch, and M. A. Abdu, Unusual ionospheric absorption characterizing energetic electron precipitation into the South Atlantic magnetic anomaly, Earth Planets Space, 54, 907–916, 2002.

    Article  Google Scholar 

  • Paulikas, G. A., Precipitation of particles at low and middle latitudes, Rev. Geophys. Space Phys., 3(5), 709–734, 1975.

    Article  Google Scholar 

  • Pinto, Jr. O. and W. D. Gonzalez, X ray measurements at the South Atlantic magnetic anomaly, J. Geophys. Res., 91(A6), 7072–7078, 1986.

    Article  Google Scholar 

  • Pinto, O. and W. D. Gonzalez, Energetic electron precipitation at the South Atlantic Magnetic Anomaly: review, J. Atmos. Terr. Phys., 5, 351–365, 1989.

    Article  Google Scholar 

  • Pinto, Jr. O., W. D. Gonzalez, and N. M. Paes Leme, VLF disturbances at the South Atlantic magnetic anomaly following magnetic storms, Planet. Space Sci., 38(5), 633–636, 1990.

    Article  Google Scholar 

  • Raben, V. J., D. E. Evans, H. H. Sauer, S. R. Sahm, and M. Huynh, Tiros/NOAA satellite space environment monitor data archive documentation: 1995 update, NOAA Tech. Memo. ERL SEL-86, 1995.

    Google Scholar 

  • Tanaka, T., Low-latitude ionospheric disturbances: Results for March 22, 1979, and their general characteristics, Geophys. Res. Lett., 13 (13), 1399–1402, 1986.

    Article  Google Scholar 

  • Torr, D. G., R. Martsha, R. Torr, C. G. Walker, and R. A. Hoffman, Particle precipitation in the South Atlantic geomagnetic anomaly, Planet. Space Sci., 23, 15–26, 1975.

    Article  Google Scholar 

  • Walt, M. and H. D. Voss, Proton precipitation during magnetic storms in August through November 1998, J. Geophys. Res., 109, A02201, doi:0.1029/2003JA010083, 2004.

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Correspondence to Masanori Nishino.

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Now retired from Nagoya University.

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Nishino, M., Makita, K., Yumoto, K. et al. Energetic particle precipitation in the Brazilian geomagnetic anomaly during the “Bastille Day storm” of July 2000. Earth Planet Sp 58, 607–616 (2006). https://doi.org/10.1186/BF03351958

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