Spread-F observations and climatology at Tucumán by automatic scaling software

Abstract:

A wide sample of ionograms of the AIS-INGV ionosonde installed in the ionospheric station of Tucumán (26.9º S, 294.6º E), Argentina is analyzed, representative of various heliogeophysical conditions. The appearance of equatorial spread-F (ESF) is studied as a function of LT in the nighttime hours and in the post-sunset hours. The development of ESF is compared to variations of hmF2 which were obtained from the automatic scaling of the ionograms, along with the main ionospheric characteristics. A routine for automatic identification of spread-F was used to identify the irregularities. F-region apparent uplifts prior to post-midnight ESF events are investigated and discussed in the frame of the capabilities of the software for automatic interpretation of ionograms.