Analysis of an eastward electrojet by means of upward continuation of ground-based magnetometer data
Article Sidebar
Published:
Dec 22, 1978
Keywords:
Magnetic variations,
Scandinavian magnetometer array,
Field separation,
Upward continuation of external fields,
Eastward auroral electrojet,
Field-aligned currents
Volumes
Vols. 1-18 (1924-1944), ISSN 0044-2801
Main Article Content
Abstract
On October 26, 1975, data from two parallel meridian chains of densely spaced magnetometers in Northern Scandinavia indicated the presence of an evening sector eastward electrojet which between 1606 and 1710 UT was two-dimensional. By separating the relevant components of the magnetic disturbance fields into internal and external parts, and by subsequent upward continuation (towards the source) of the external horizontal component, equivalent height-integrated ionospheric current densities were derived as a function of latitude and time. Whereas the demarcation line between the eastward and westward ionospheric electrojet currents remained stationary, the sharp southern border of the eastward electrojet moved towards the south with a speed of about 50 ms-1 , possibly indicating an earthward movement of the inner edge of the magnetospheric plasma sheet. The maximum eastward height-integrated current density was of the order of 0.5 Am-1 , the corresponding large-scale field-aligned current density has been estimated to have been of the order of 1.0 μAm-2 . After 1630 UT there was evidence for a superposed stationary small-scale structure (wavelength of the order of 250 km) in the eastward flow, which would imply a pair of local field-aligned current sheets possibly related to an auroral arc.
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Article Details
How to Cite
Mersmann, U., Baumjohann, W., Kuppers, F., & Lange, K. (1978). Analysis of an eastward electrojet by means of upward continuation of ground-based magnetometer data. Journal of Geophysics, 45(1), 281-298. Retrieved from https://journal.geophysicsjournal.com/JofG/article/view/179
Section
References
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Banks, P.M., Doupnik, J.R., Akasofu, S.-I. (1973) Electric field observations by incoherent scatter radar in the auroral zone. J. Geophys. Res. 78:6607-6622
Baumjohann, W., Greenwald, R.A., Kuppers, F. (1978) Joint magnetometer array and radar backscatter observations of auroral currents in Northern Scandinavia. J. Geophys. 44:373-383
Beaujardiere, O. de la, Vondrak, R., Baron, M. (1977) Radar observations of electric fields and currents associated with auroral arcs. J. Geophys. Res. 82:5051-5062
Bostrom, R. (1964) A model of the auroral electrojets. J. Geophys. Res. 69:4983-5000
Brekke, A., Doupnik, J.R., Banks, P.M. (1974) Incoherent scatter measurements of E-region conductivities and currents in the auroral zone. J. Geophys. Res. 79:3773-3790
Carlson, C.W., Kelley, M.C. (1977) Observation and interpretation of particle and electric field measurements inside and adjacent to an active auroral arc. J. Geophys. Res. 82:2349-2360
Casserly, R.T., Cloutier, P.A. (1975) Rocket-based magnetic observations of auroral Birkeland currents in association with a structured auroral arc. J. Geophys. Res. 80:2165-2168
Czechowsky, P. (1971) Calculation of an equivalent current system in the polar E-region. Radio Sci. 6:247-253
Evans, D.S., Maynard, N.C., Troim, J., Jacobsen, T., Egeland, A. (1977) Auroral electric field and particle comparisons. 2. Electrodynamics of an arc. J. Geophys. Res. 82:2235-2249
Fukushima, N. (1976) Generalized theorem for no ground magnetic effect of vertical currents connected with Pedersen currents in the uniform-conductivity ionosphere. Rep. Ionos. Space Res. Jpn. 30:35-40
Gough, D.I., Reitzel, J.S. (1967) A portable three component magnetic variometer. J. Geomagn. Geoelectr. 19:203-215
Grant, F.S., West, G.F. (1965) Interpretation theory in applied geophysics. McGraw-Hill, New York
Gustafsson, G. (1970) A revised corrected geomagnetic coordinate system. Ark. Geofys. 5:595-617
Horwitz, J.L., Doupnik, J.R., Banks, P.M. (1978) Chatanika radar observations of the latitudinal distributions of auroral zone electric fields, conductivities, and currents. J. Geophys. Res. 83:1463-1481
Iijima, T., Potemra, T.A. (1976) The amplitude distribution of field-aligned currents at northern high latitudes observed by Triad. J. Geophys. Res. 81:2165-2174
Iijima, T., Potemra, T.A. (1978) Large-scale characteristics of field-aligned currents associated with substorms. J. Geophys. Res. 83:599-615
Kamide, Y., Brekke, A. (1975) Auroral electrojet current density deduced from the Chatanika radar and from the Alaska meridian chain of magnetic observatories. J. Geophys. Res. 80:587-594
Kamide, Y., Brekke, A. (1977) Altitude of the eastward and westward auroral electrojets. J. Geophys. Res. 82:2851-2853
Kamide, Y., Fukushima, N. (1972) Positive geomagnetic bays in evening high-latitudes and their possible connection with partial ring current. Rep. Ionos. Space Res. Jpn. 26:79-101
Kamide, Y., Horwitz, J.L. (1978) Chatanika radar observations of ionospheric and field-aligned currents. J. Geophys. Res. 83:1063-1070
Kamide, Y., Rostoker, G. (1977) The spatial relationship of field-aligned currents and auroral electrojets to the distribution of nightside auroras. J. Geophys. Res. 82:5589-5608
Kertz, W. (1954) Modelle fur erdmagnetisch induzierte elektrische Strome im Untergrund. Nachr. Akad. Wiss. Goettingen 1954, Math.-Phys. Kl.:101-110
Kuppers, F., Post, H. (1979) A second generation Gough-Reitzel magnetometer, J. Geomagn. Geoelectr. (accepted for publication)
Kuppers, F., Untiedt, J., Baumjohann, W., Lange, K., Jones, A. (1979) A two-dimensional magnetometer array for ground-based observations of auroral zone electric currents during the International
Magnetospheric Study (IMS). J. Geophys. 46:429-450
Lui, A.T.Y., Venkatesan, D., Anger, C.D., Akasofu, S.-I., Heikkila, W.J., Winningham, J.D., Burrows, J.R. (1977) Simultaneous observations of particle precipitations and auroral emissions by the Isis 2 satellite in the 19-24 MLT sector. J. Geophys. Res. 82:2210-2226
Mallinckrodt, A.J., Carlson, C.W. (1978) Relations between transverse electric fields and the field-aligned currents. J. Geophys. Res. 83:1426-1432
Maynard, N.C. (1974) Electric field measurements across the Harang discontinuity. J. Geophys. Res. 79:4620-4631
Maynard, N.C., Evans, D.S., Maehlum, B., Egeland, A. (1977) Auroral vector electric field and particle comparisons. I. Premidnight convection topology. J. Geophys. Res. 82v2227-2234
McNish, A.G. (1938) Heights of electric currents near the auroral zone. Terr. Magn. Atmos. Electr. 43:67-75
Mende, S.B., Eather, R.H. (1976) Monochromatic all-sky observations and auroral precipitation patterns. J. Geophys. Res. 81:3771-3780
Oldenburg, D.W. (1976) Ionospheric current structure as determined from groundbased magnetometer data. Geophys. J. 46:41-66
Oldenburg, D.W. (1978) A quantitative technique for modelling ionospheric and magnetospheric current distributions. J. Geo phys. Res. 83:3320-3326
Rostoker, G. (1972) Polar magnetic substorms. Rev. Geophys. Space Phys. 10:157-211
Rostoker, G., Armstrong, J.C., Zmuda, A.J. (1975) Field-aligned current flow associated with intrusion of the substorm-intensified westward electrojet into the evening sector. J. Geo phys. Res. 80:3571-3579
Rostoker, G., Kisabeth, J.L. (1973) Response of the polar electrojets in the evening sector to polar magnetic substorms. J. Geophys. Res. 78:5559-5571
Sato, T. (1978) A theory of quiet auroral arcs. J. Geophys. Res. 83:1042-1048
Scrase, F.J. (1967) The electric current associated with polar magnetic sub-storms. J. Atmos. Terr. Phys. 29:567-579
Siebert, M., Kertz, W. (1957) Zur Zerlegung eines lokalen erdmagnetischen Feldes in ausseren und inneren Anteil. Nachr. Akad. Wiss. Gottingen 1957, Math.-Phys. Kl.:87-112
Stauning, P., Christensen, B. (1977) Compilation of Ionlab riometer data for IMS-Workshop in Hankasalmi. Ionlab Rep. R41, Lyngby (Denmark)
Sugiura, M., Potemra, T.A. (1976) Net field-aligned currents observed by Triad. J. Geophys. Res. 81:2155-2164
Untiedt, J., Pellinen, R., Kuppers, F., Opgenoorth, H.J., Pelster, W.D., Baumjohann, W., Ranta, H., Kangas, J., Czechowsky, P., Heikkila, W.J. (1978) Observations of the initial development of an auroral and magnetic substorm at magnetic midnight. J. Geophys. 45:41-65
Wallis, D.D. (1976) Comparison of auroral electrojets and the visible aurora. In: McCormack, B.M. (Ed.) Magnetospheric particles and fields, pp. 247-255. D. Reidel, Dordrecht
Wallis, D.D., Anger, C.D., Rostoker, G. (1976) The spatial relationship of auroral electrojets and visible aurora in the evening sector. J. Geophys. Res. 81:2857-2869
Weaver, J.T. (1964) On the separation of local geomagnetic fields into external and internal parts. J. Geophys. 30:29-36
Wedde, T., Doupnik, J.R., Banks, P.M. (1977) Chatanika observations of the latitudinal structure of electric fields and particle precipitation on November 21, 1975. J. Geophys. Res. 82:2743-2751
Wescott, E.M., Stolarik, J.D., Heppner, J.P. (1969) Electric fields in the vicinity of auroral forms from motions of barium vapor releases. J. Geophys. Res. 74:3469-3487
Winningham, J.D., Yasuhara, F., Akasofu, S.-I., Heikkila, W.J. (1975) The latitudinal morphology of 10-eV to 10-keV electron fluxes during magnetically quiet and disturbed times in the 2100-0300 MLT sector. J. Geophys. Res. 80:3148-3171
Zmuda, A.J., Armstrong, J.C. (1974) The diurnal flow pattern of field-aligned currents. J. Geophys. Res. 79:4611-4619
Banks, P.M., Doupnik, J.R., Akasofu, S.-I. (1973) Electric field observations by incoherent scatter radar in the auroral zone. J. Geophys. Res. 78:6607-6622
Baumjohann, W., Greenwald, R.A., Kuppers, F. (1978) Joint magnetometer array and radar backscatter observations of auroral currents in Northern Scandinavia. J. Geophys. 44:373-383
Beaujardiere, O. de la, Vondrak, R., Baron, M. (1977) Radar observations of electric fields and currents associated with auroral arcs. J. Geophys. Res. 82:5051-5062
Bostrom, R. (1964) A model of the auroral electrojets. J. Geophys. Res. 69:4983-5000
Brekke, A., Doupnik, J.R., Banks, P.M. (1974) Incoherent scatter measurements of E-region conductivities and currents in the auroral zone. J. Geophys. Res. 79:3773-3790
Carlson, C.W., Kelley, M.C. (1977) Observation and interpretation of particle and electric field measurements inside and adjacent to an active auroral arc. J. Geophys. Res. 82:2349-2360
Casserly, R.T., Cloutier, P.A. (1975) Rocket-based magnetic observations of auroral Birkeland currents in association with a structured auroral arc. J. Geophys. Res. 80:2165-2168
Czechowsky, P. (1971) Calculation of an equivalent current system in the polar E-region. Radio Sci. 6:247-253
Evans, D.S., Maynard, N.C., Troim, J., Jacobsen, T., Egeland, A. (1977) Auroral electric field and particle comparisons. 2. Electrodynamics of an arc. J. Geophys. Res. 82:2235-2249
Fukushima, N. (1976) Generalized theorem for no ground magnetic effect of vertical currents connected with Pedersen currents in the uniform-conductivity ionosphere. Rep. Ionos. Space Res. Jpn. 30:35-40
Gough, D.I., Reitzel, J.S. (1967) A portable three component magnetic variometer. J. Geomagn. Geoelectr. 19:203-215
Grant, F.S., West, G.F. (1965) Interpretation theory in applied geophysics. McGraw-Hill, New York
Gustafsson, G. (1970) A revised corrected geomagnetic coordinate system. Ark. Geofys. 5:595-617
Horwitz, J.L., Doupnik, J.R., Banks, P.M. (1978) Chatanika radar observations of the latitudinal distributions of auroral zone electric fields, conductivities, and currents. J. Geophys. Res. 83:1463-1481
Iijima, T., Potemra, T.A. (1976) The amplitude distribution of field-aligned currents at northern high latitudes observed by Triad. J. Geophys. Res. 81:2165-2174
Iijima, T., Potemra, T.A. (1978) Large-scale characteristics of field-aligned currents associated with substorms. J. Geophys. Res. 83:599-615
Kamide, Y., Brekke, A. (1975) Auroral electrojet current density deduced from the Chatanika radar and from the Alaska meridian chain of magnetic observatories. J. Geophys. Res. 80:587-594
Kamide, Y., Brekke, A. (1977) Altitude of the eastward and westward auroral electrojets. J. Geophys. Res. 82:2851-2853
Kamide, Y., Fukushima, N. (1972) Positive geomagnetic bays in evening high-latitudes and their possible connection with partial ring current. Rep. Ionos. Space Res. Jpn. 26:79-101
Kamide, Y., Horwitz, J.L. (1978) Chatanika radar observations of ionospheric and field-aligned currents. J. Geophys. Res. 83:1063-1070
Kamide, Y., Rostoker, G. (1977) The spatial relationship of field-aligned currents and auroral electrojets to the distribution of nightside auroras. J. Geophys. Res. 82:5589-5608
Kertz, W. (1954) Modelle fur erdmagnetisch induzierte elektrische Strome im Untergrund. Nachr. Akad. Wiss. Goettingen 1954, Math.-Phys. Kl.:101-110
Kuppers, F., Post, H. (1979) A second generation Gough-Reitzel magnetometer, J. Geomagn. Geoelectr. (accepted for publication)
Kuppers, F., Untiedt, J., Baumjohann, W., Lange, K., Jones, A. (1979) A two-dimensional magnetometer array for ground-based observations of auroral zone electric currents during the International
Magnetospheric Study (IMS). J. Geophys. 46:429-450
Lui, A.T.Y., Venkatesan, D., Anger, C.D., Akasofu, S.-I., Heikkila, W.J., Winningham, J.D., Burrows, J.R. (1977) Simultaneous observations of particle precipitations and auroral emissions by the Isis 2 satellite in the 19-24 MLT sector. J. Geophys. Res. 82:2210-2226
Mallinckrodt, A.J., Carlson, C.W. (1978) Relations between transverse electric fields and the field-aligned currents. J. Geophys. Res. 83:1426-1432
Maynard, N.C. (1974) Electric field measurements across the Harang discontinuity. J. Geophys. Res. 79:4620-4631
Maynard, N.C., Evans, D.S., Maehlum, B., Egeland, A. (1977) Auroral vector electric field and particle comparisons. I. Premidnight convection topology. J. Geophys. Res. 82v2227-2234
McNish, A.G. (1938) Heights of electric currents near the auroral zone. Terr. Magn. Atmos. Electr. 43:67-75
Mende, S.B., Eather, R.H. (1976) Monochromatic all-sky observations and auroral precipitation patterns. J. Geophys. Res. 81:3771-3780
Oldenburg, D.W. (1976) Ionospheric current structure as determined from groundbased magnetometer data. Geophys. J. 46:41-66
Oldenburg, D.W. (1978) A quantitative technique for modelling ionospheric and magnetospheric current distributions. J. Geo phys. Res. 83:3320-3326
Rostoker, G. (1972) Polar magnetic substorms. Rev. Geophys. Space Phys. 10:157-211
Rostoker, G., Armstrong, J.C., Zmuda, A.J. (1975) Field-aligned current flow associated with intrusion of the substorm-intensified westward electrojet into the evening sector. J. Geo phys. Res. 80:3571-3579
Rostoker, G., Kisabeth, J.L. (1973) Response of the polar electrojets in the evening sector to polar magnetic substorms. J. Geophys. Res. 78:5559-5571
Sato, T. (1978) A theory of quiet auroral arcs. J. Geophys. Res. 83:1042-1048
Scrase, F.J. (1967) The electric current associated with polar magnetic sub-storms. J. Atmos. Terr. Phys. 29:567-579
Siebert, M., Kertz, W. (1957) Zur Zerlegung eines lokalen erdmagnetischen Feldes in ausseren und inneren Anteil. Nachr. Akad. Wiss. Gottingen 1957, Math.-Phys. Kl.:87-112
Stauning, P., Christensen, B. (1977) Compilation of Ionlab riometer data for IMS-Workshop in Hankasalmi. Ionlab Rep. R41, Lyngby (Denmark)
Sugiura, M., Potemra, T.A. (1976) Net field-aligned currents observed by Triad. J. Geophys. Res. 81:2155-2164
Untiedt, J., Pellinen, R., Kuppers, F., Opgenoorth, H.J., Pelster, W.D., Baumjohann, W., Ranta, H., Kangas, J., Czechowsky, P., Heikkila, W.J. (1978) Observations of the initial development of an auroral and magnetic substorm at magnetic midnight. J. Geophys. 45:41-65
Wallis, D.D. (1976) Comparison of auroral electrojets and the visible aurora. In: McCormack, B.M. (Ed.) Magnetospheric particles and fields, pp. 247-255. D. Reidel, Dordrecht
Wallis, D.D., Anger, C.D., Rostoker, G. (1976) The spatial relationship of auroral electrojets and visible aurora in the evening sector. J. Geophys. Res. 81:2857-2869
Weaver, J.T. (1964) On the separation of local geomagnetic fields into external and internal parts. J. Geophys. 30:29-36
Wedde, T., Doupnik, J.R., Banks, P.M. (1977) Chatanika observations of the latitudinal structure of electric fields and particle precipitation on November 21, 1975. J. Geophys. Res. 82:2743-2751
Wescott, E.M., Stolarik, J.D., Heppner, J.P. (1969) Electric fields in the vicinity of auroral forms from motions of barium vapor releases. J. Geophys. Res. 74:3469-3487
Winningham, J.D., Yasuhara, F., Akasofu, S.-I., Heikkila, W.J. (1975) The latitudinal morphology of 10-eV to 10-keV electron fluxes during magnetically quiet and disturbed times in the 2100-0300 MLT sector. J. Geophys. Res. 80:3148-3171
Zmuda, A.J., Armstrong, J.C. (1974) The diurnal flow pattern of field-aligned currents. J. Geophys. Res. 79:4611-4619