Publication Date:
2015-10-01
Description:
The dependence of the upward field-aligned current density ( J || ) at the dayside magnetopause boundary layer is well described by a simple analytic model based on a velocity shear generator. A previous observational survey confirmed the scaling properties predicted by the analytical model are applicable between 11 and 17 MLT. We utilize the analytic model to predict field-aligned currents using solar wind and ionospheric parameters and compare with direct observations. The calculated and observed parallel currents are in excellent agreement, suggesting the model may be useful to infer boundary layer structures. However, near noon, where velocity shear is small, the kinetic pressure gradients and thermal currents, which are not included in the model, could make a small but significant contribution to J || . Excluding data from noon, our least square fit returns log( J ||,max_cal ) = (0.96 ± 0.04) log( J ||_obs ) + (0.03 ± 0.01) where J ||,max_cal = calculated J ||,max and J ||_obs = observed J || .
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
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