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Joule heating due to vertical ion currents in the lower thermosphere over the dip equator
Earth, Planets and Space volume 50, pages833–837(1998)
The theory of equatorial electrojet predicts the presence of vertical ion currents (Pedersen currents) as a part of the electrojet current system. The vertical ion current density profile over the dip equator, that forms a part of the meridional current system is derived from an electrojet model. The joule heating due to these currents flowing upward during daytime for a local time for 1100 hrs has been estimated. The primary east-west current density of the model is kept at the same value as that measured by means of rocket-borne magnetometer on one occasion. The electrical power dissipated as heat in the narrow belt in the height region of 100–180 km is estimated and found to be significant. The height of maximum power dissipation coincides with the altitude of maximum ion velocity i.e. 122 km. By solving the heat conduction equation we obtain a maximum temperature increase of 8°K around 135 km. The importance of this localized heating in the lower thermosphere around ±2° of the dip equator is discussed.
Anandarao, B. G., Effects of gravity wave winds and wind shears on the equatorial electrojet, Geophys. Res. Lett., 3, 545–548, 1976.
Anandarao, B. G. and R. Raghavarao, Effects of vertical shears in the zonal winds on the electrojet, Space. Res., XIX, 283–286, 1979.
Anandarao, B. G. and R. Raghavarao, Effects of vertical shears in the currents and fields of the equatorial due to zonal and meridional winds, J. Geophys. Res., 92, 2514–2526, 1987.
Anandarao, B. G., R. Raghavarao, J. N. Desai, and G. Haerendel, Vertical winds and turbulence over Thumba, J. Atmos. Terr. Phys., 40, 157–163, 1978.
Banks, P. M. and G. Kockarts, Aeronomy Part B, Academic Press, N.Y., 1973.
Cole, K. D., Joule heating of the upper atmosphere, Aust. J. Phys., 15, 223–235, 1962.
Cole, K. D., Electrodynamic heating and movement of the thermosphere, Planet. Space Sci., 19, 59–75, 1971.
Forbes, J. M., The equatorial electrojet, Rev. Geophys. Space Phys., 19, 469–504, 1981.
Gagnepain, J., M. Crochet, and A. D. Richmond, Comparison of equatorial electrojet models, J. Atmos. Terr. Phys., 39, 1119–1124, 1977.
Jacchia, L. G., Smithsonian. Astrophys. Obs. Special Rep., No. 375, 1977.
Kato, S., Joule heating at the magnetic equator, Planet. Space Sci., 11, 1297–1302, 1963.
Raghavarao, R. and B. G. Anandarao, Vertical winds as a plausible cause for equatorial counter-electrojet, Geophys. Res. Lett., 7, 357–360, 1980.
Raghavarao, R., R. Sridharan, and R. Suhasini, The importance of vertical ion currents in the nighttime ionization in the equatorial electrojet, J. Geophys. Res., 89, 11033–11037, 1984.
Rees, D., P. D. Bhavsar, J. N. Desai, S. P. Gupta, A. D. Farmer, and P. Rounce, Preliminary report on commonwealth collaborative rocket programme from Thumba equatorial rocket launching station for the investigation of atmospheric and ionospheric processes, Space. Res., XVI, 407–412, 1976.
Sampath, S., T. S. G. Sastry, K. Oyama, and K. Hirao, Joule heating due to the equatorial electrojet as observed by rocket-borne probes, Space. Res., XIV, 253–258, 1974.
Shirke, J. S., R. Sridharan, S. R. Das, A. D. Danilov, A. A. Pokhunkov, and V. A. Semenov, Simultaneous measurements of ionospheric parameters at the dip equator, Space. Res., XVII, 403–407, 1977.
Untiedt, J., A model of the equatorial electrojet involving meridional currents, J. Geophys. Res., 72, 5799–5810, 1967.
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Raghavarao, R., Sridharan, R. & Suhasini, R. Joule heating due to vertical ion currents in the lower thermosphere over the dip equator. Earth Planet Sp 50, 833–837 (1998) doi:10.1186/BF03352176
- Power Dissipation
- Joule Heating
- Vertical Wind
- Lower Thermosphere
- Equatorial Electrojet