ON THE POTENTIAL APPLICABILITY OF THE SIMPLIFIED IONOSPHERIC REGIONALMODEL TO DIFFERENT MIDLATITUDE AREAS

The simplified ionospheric regional model (SIRM) was originally develo ped for modeling the most relevant ionospheric characteristics over Eu rope for radiocommunication purposes. The model, based mainly on the F ourier expansion of a reference past data set, is here adapted and app lied to different sets of dishomogeneous periods of observed data comi ng from a sparse network of ionospheric stations in midlatitude areas, that is, northeastern North America, southeastern South America, nort heast Asia, and southeast Australia. Notwithstanding the simple SIRM f ormulation and the reduced number of numerical coefficients involved, a good agreement has been found between modeled and observed monthly m edian values of f(o)F(2) and M(3000)F-2 under different heliogeophysic al conditions.