Modeling the influence of changes in neutral atmosphere parameters on ionospheric electron density

Based on the modified numerical model of the ionosphere and plasmasphere developed at ISTP SB RAS, we calculated the height profiles of the electron density Ne for the quiet and disturbed thermospheric conditions of January 25, 2009 at the geographical location of Irkutsk (52.4N, 104.3E). The disturbed conditions were simulated by varying the neutral temperature T in the thermosphere. At heights below 180 km and above 250 km, with an increase/decrease in T, an increase/decrease in Ne occurs. At 180–250 km, the opposite pattern is seen: an increase/decrease in T causes a decrease/increase in Ne. The opposite pattern of the change in the Ne profile is associated with the influence of the atomic oxygen to molecular nitrogen density ratio [O]/[N2] at heights of the F-region. Quantitative estimates of the change in Ne at different heights with changes in the neutral temperature were obtained. It has been established that a change in T by 1 K leads to a change in Ne by 0.2–0.3%. The modeling results were compared with observations of the peak electron density NmF2 obtained with the Irkutsk ionosonde during the sudden stratospheric warming in January 2009.