Abstract
Wiener filters are derived from the horizontal field data of two adjacent equatorial electrojet stations, Adis Ababa and Trivandrum from several sequences of quiet days. The time invariant property of the filter is established and the filter is applied to conditions marked by afternoon counter electrojet events. The prediction efficiency is shown to be consistently high. Possible uses of this technique in studies related to generating mechanisms of counter electrojet events and the day-to-day variability in electrojet currents are indicated. Inter-relationships and day-to-day variability of different components of the fields at the two stations are highlighted.
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References
Bhargava B N and Sastri N S 1977 A comparison of days with and without occurrence of counter electrojet afternoon events in the Indian region;Ann. Geophys. 33 329–332
Bhargava B N, Arora B R and Sastri N S 1983 Indices of equatorial electrojet and counter electrojet in the Indian region: Evolution of the indices and their authenticity;Proc. Indian Acad. Sci. Earth Planet. Sci. 92 45–56
Clauer C R 1986 The technique of linear prediction filters applied to studies of solar wind-magnetosphere coupling in “Solar wind-Magnetosphere Coupling”, (eds) Y Kamide and J A Slavin;Terra Pub, Tokyo, Japan pp 39–58
Clauer C R, McPherron R L and Searls C 1983 Solar wind control of low latitude asymmetric field;J. Geophys. Res. 88 2123–2130
Fay R A, Garrity C R, McPherron R L and Bargatze L F 1986 Prediction filters for the Dst index and the polar cap potential in “Solar wind-Magnetosphere Coupling” (eds) Y Kamide and J A Slavin;Terra Pub, Tokyo, Japan pp. 111–118
Gouin P 1962 Reversal of the magnetic daily variation at Adis Ababa;Nature (London) 193 1145–1146
Iyemori T, Maeda H and Kamei T 1979 Impulse response of geomagnetic indices to interplanetary magnetic field;J. Geomagn. Geoelectr. 31 1–9
Iyemori T and Maeda H 1980 Prediction of geomagnetic activities from solar wind parameters based on the linear prediction theory;Solar Terr. Prediction Proceedings, US Dept. of Commerce Boulder CO, USA, Vol. 4 A 1
Levinson N 1949 The Wiener R M S (Root Mean Square) error criterion in filter design and prediction in Appendix B. N. Wiener's book reprint
McPherron R L, Baker B D N and Bargatze L F 1986 Linear filters as a method of real time prediction of geomagnetic activity in “Solar wind-Magnetosphere Coupling”, (eds) Y Kamide and J A Slavin;Terra Pub, Tokyo 85–96
Rao K N and Raja Rao K S 1963 Quiet day magnetic variations near the magnetic equator;Nature (London) 200 460–461
Rastogi R G 1973 Counter equatorial electrojet currents in Indian zone Planet;Space Sci. 21 1355–1365
Rastogi R G 1974 Westward equatorial electrojet during daytime hours;J. Geophys. Res. 79 1503–1512
Rastogi R G and Iyer K N 1976 Quiet day variation of geomagnetic H field at low latitudes;J. Geomagn. Geoelectr. 28 461–479
Robinson E A 1967 Multi-channel time series analysis with digital computer programs Holden Day, San Francisco, 232–259
Somayajulu V V 1988 Behaviour of harmonic components of the geomagnetic field during counter electrojet events;J. Geomagn. Geoelectr. 40 111–130
Schlapp D H and Mann R J 1983 The spatial scale of correlation of the day-to-day variability of Sq Geophys.;J. R. Astron. Soc. 73 671–673
Wiener N 1942 Extrapolation interpolation and smoothing of stationary time series with engineering applications; (Cambridge Mass: MIT Press)
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Rangarajan, G.K. Application of the Linear Prediction filters in equatorial electrojet studies. Proc. Indian Acad. Sci. (Earth Planet Sci.) 101, 329–338 (1992). https://doi.org/10.1007/BF02893008
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DOI: https://doi.org/10.1007/BF02893008