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A study of local time and longitudinal variability of the amplitude of the equatorial electrojet observed in POGO satellite data

Earth, Planets and Space volume 51, pages 373–381 (1999)Cite this article

Abstract

The local time and longitudinal variations of the amplitude of the equatorial electrojet (EE) are investigated using the POGO series satellite data. An iterative normalization scheme is developed to separate the variations of the amplitude of the EE with respect to longitude and local time. The resulting local time variation of the EE compares favorably with observatory based studies; however, the longitudinal variation is not well resolved. The altitude of the satellite is another factor that affects the amplitude of the EE. We use a simple linear scaling of amplitude of the EE with the inverse of the satellite altitude. An experiment including only the satellite passes below 450 km altitude indicates that there may be problems in correcting the data from higher altitudes. The reason behind the discrepancy between the results from the data limited to below 450 km and the full data set is not understood and requires further investigation.

References

  • Agu, C. E. and C. A. Onwumechili, Comparison of the POGO satellite and ground measurements of the magnetic field of the equatorial electrojet, J. Atmos. Terr. Phys., 43, 801–807, 1981.

    Article  Google Scholar 

  • Cain, J. C. and R. E. Sweeney, The POGO data, J. Atmos. Terr. Phys., 35, 1231–1247, 1973.

    Article  Google Scholar 

  • Doumouya, V., J. Vassal, Y. Cohen, O. Fambitakoye, and M. Menvielle, Equatorial electrojet at African longitudes: First results from magnetic measurements, Ann. Geophysicae, 16, 658–676, 1998.

    Article  Google Scholar 

  • Forbes, J. M., The equatorial electrojet, Rev. Geophys., 19, 469–504, 1981.

    Article  Google Scholar 

  • Forbes, J. M. and R. S. Lindzen, Atmospheric solar tides and their electrodynamic effects-II. The equatorial electrojet, J. Atmos. Terr. Phys., 38, 911–920, 1976.

    Article  Google Scholar 

  • Gupta, J. C. and S. Chapman, Manual of the coefficients of the first four harmonics of the solar and lunar daily geomagnetic variations computed from IGY/C and certain other data, NCAR Pub., MS-68-110, 1–23, 1970.

    Google Scholar 

  • Kane, R. P., Comparison of geomagnetic changes in India and the POGO data, J. Atmos. Terr. Phys., 35, 1249–1252, 1973.

    Article  Google Scholar 

  • Langel, R. A., Global magnetic anomaly maps derived from POGO spacecraft data, Phys. Earth Planet. Inter., 62, 208–230, 1990.

    Article  Google Scholar 

  • Langel, R. A., Study of the crust and mantle using magnetic surveys by Magsat and other satellites, Proc. Indian Acad. Sci., 99, 581–618, 1990.

    Google Scholar 

  • Langel, R. A., The use of low altitude satellite dta bases for modeling of core and crustal fields and the separation of external and internal fields, Surv. Geophys., 14, 31–87, 1993.

    Article  Google Scholar 

  • Langel, R. A., R. L. Coles, and M. A. Mayhew, Comparison of magnetic anomalies of lithospheric origin measured by satellite and airborne magnetometers over western Canada, Can. J. Earth Sci., 17, 876–887, 1980.

    Article  Google Scholar 

  • Langel, R. A., M. Purucker, and M. Rajaram, The equatorial electrojet and associated currents as seen in Magsat data, J. Atmos. Terr. Phys., 55, 1233–1269, 1993.

    Article  Google Scholar 

  • Maeda, H., T. Iyemori, T. Araki, and T. Kamei, New evidence of a meridional current system in the equatorial ionosphere, Geophys. Res. Lett., 9, 341–344, 1982.

    Article  Google Scholar 

  • Onwumechili, C. A., Satellite measurements of the equatorial electrojet, J. Geomag. Geoelectr., 37, 11–36, 1985.

    Article  Google Scholar 

  • Onwumechili, C. A. and C. E. Agu, General features of the magnetic field of the equatorial electrojet measured by the POGO satellites, Planet. Space Sci., 28, 1125–1130, 1980.

    Article  Google Scholar 

  • Rastogi, R. G., The equatorial electrojet: magnetic and ionospheric effects, in Geomagnetism, Vol. 3. Chap. 7, edited by J. A. Jacobs, pp. 461–525, Academic Press, London, 1989.

    Google Scholar 

  • Ravat, D. and W. J. Hinze, Considerations of variations in ionospheric fields effects in mapping equatorial lithospheric Magsat magnetic anomalies, Geophys. J. Int., 113, 387–398, 1993.

    Article  Google Scholar 

  • Roy, M., Equatorial ionospheric currents derived from MAGSAT data, Geophys. Res. Lett., 10, 741–744, 1983.

    Article  Google Scholar 

Download references

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Author notes

  1. H. R. Kim

    Present address: Department of Geological Sciences, Ohio State University, Columbus, OH, 42325, USA

Authors and Affiliations

  1. Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette, IN, 47907, USA

    H. R. Kim & Scott D. King

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  1. H. R. Kim
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  2. Scott D. King
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Kim, H.R., King, S.D. A study of local time and longitudinal variability of the amplitude of the equatorial electrojet observed in POGO satellite data. Earth Planet Sp 51, 373–381 (1999). https://doi.org/10.1186/BF03352241

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  • DOI: https://doi.org/10.1186/BF03352241

Keywords

  • Local Time
  • Magnetic Anomaly
  • Longitudinal Variation
  • Equatorial Electrojet
  • Satellite Pass