Electric conductivities, electric fields and auroral particle energy injection rate in the auroral ionosphere and their empirical relations to the horizontal magnetic disturbances

Recent progress in modeling ionospheric current systems requires global conductivity models which can reflect substorm conditions on an instantaneous basis. For this purpose, empirical relations of the North-South component ( ΔH) of the magnetic disturbance field observed at College with the Pedersen ( Σ_p) and Hall ( Σ_H) conductivities deduced from the Chatanika radar data and their ratio ( Σ _H/Σ _p) are examined. These empirical formulas allow us to construct approximate distribution patterns of Σ_p and Σ_{> H} over the entire polar region on the basis of the distribution of ΔH at given instants by devising an appropriate weighting function for both the polar cap and the subauroral region. The global conductivity distributions thus obtained are compared with those employed by Kamide et al. (1981) and Spiro et al. (1982). The comparisons show that the gross features are similar among them. In addition, we also examine the relationship of ΔH with the North-South component of the electric field with the particle energy injection rate ( u_A) estimated from the Chatanika radar data. Based on the empirical relation between Σ_H and u_A the global distribution of the latter over the entire polar region at particular instants can also be obtained.