The applicability of using theoretical models to improve ionospheric maps

Electron density distributions in the midlatitude ionospheric F region are calculated by solving the time-dependent ion continuity equation numerically, including the effects of production, loss and transport of ionization. The object of the study is to obtain values of the F region critical frequency which can be used to improve the prediction of ionospheric parameters over regions of the earth which are inaccessible to ground-based measurements. This is accomplished by including into the theoretical calculations realistic physical processes along with a realistic geomagnetic field model. Input parameters are adjusted so that agreement is achieved between calculated and observed f0F2 values as a function of local time at two different stations. It is assumed that these same input parameters (i.e., neutral wind field, neutral atmospheric model, etc.) are valid at the intermediate region of interest where the major difference is the geomagnetic field line configuration. Coefficients that yield global representations of f0F2 are then determined using the theoretically derived f0F2 values and the predicted critical frequencies are compared with observed values to estimate the degree of improvement