A numerical study of the quite-time F-region equatorial anomaly at solar maximum and minimum

Time-dependent numerical models of the F-region equatorial anomaly for quite-time (A(p) = 4) equinox and solstice conditions in solar maximum (F10.7 = 243) and minimum (F10.7 = 68) based on the geographic axially centred dipole (CD) field approximation are developed. The modelled F-region consists of a single positive ion species, 0+. Diurnal profiles of equatorial EXB and zonal drift velocities of the F-region plasma required in the computation of the models are taken from Jicamarca measurements. The meridional wind field assumed in the anomaly region is based on NCAR TGCM and HWM-87 horizontal wind models. Model predictions of the anomaly features such as temporal and spatial evolution of the anomaly crests, their maximum latitudinal separation, crest to trough ratios and diurnal variation of the equatorial foF2 are described and compared with experimental observations.