Abstract:
To understand the dynamics of the equatorial ionosphere and mitigate its effect on radio
wave propagation, vertical ion drift velocity empirical models have been developed using limited
ground‐based and/or space‐based observations. These models, however, have not yet been validated in
detail using recent observations for sufficiently different longitudinal sectors. In this paper we have
evaluated the performance of two empirical models and also propose a simplified vertical drift velocity
model based on basic physics laws (i.e., Ampere's and Ohm's laws) that we call it parameterized drift
velocity (PDV) model. These models have been applied to estimate the E region electric field and the
associated F region E × B drift velocity using observed horizontal magnetic fields, due to equatorial
electrojet current, as model driver input. Drift velocities obtained from these models are compared with
the Communication/Navigation Outage Forecasting System (C/NOFS) satellite in situ vertical drift
observations for different longitudinal sectors. It is found, for all longitudinal sectors considered in this
study, that the vertical drift velocity obtained from a model based on physics laws has shown better
agreement with C/NOFS observations as compared to the outputs of other empirical models. Moreover, it
is shown that the Anderson empirical model performs better than the International Reference
Ionosphere model.
