Variability of F2-layer peak characteristics at low latitude in Argentina for high and low solar activity and comparison with the IRI-2016 model

This work presents the study of the variability of foF2 and hmF2 at a low latitude station in South America (Tucumán, 26.9°S, 294.6°E; magnetic latitude 15.5°S, Argentina). Ground based ionosonde measurements obtained during different seasonal and solar activity conditions (a year of low solar activity, 2009 and one of high solar activity, 2016) are considered in order to compare the ionospheric behavior. The parameters used to analyze the variability are the median, upper and lower quartiles. In addition, the foF2 values are compared with those estimated by the International Reference Ionosphere (IRI) - 2016 model. It is found that: a) A clear dependence on solar activity is observed in foF2 and hmF2, both increase with increase in solar activity. b) the variability of foF2 is higher at low solar activity, this behavior is not observed in hmF2 that present similar variability during both periods. c) the variability of foF2 is larger at night than during the day, this behavior is more pronounced during the high solar activity period. d) The variability of foF2 is higher than that of hmF2. e) Significant planetary wave spectral peaks at about 2 and 5 days are observed at high and low solar activity. f) In general, IRI overestimates foF2 during daytime, and underestimates it at post-sunset period, a better agreement is shown during nighttime.