Mid-latitude spread F over an Extended European area

A three-year study (2017, 2020, 2021) of diurnal and seasonal characteristics of nighttime spread F over eight Digisonde European stations covering an extended latitude and longitude range of the European mid-latitude ionosphere is presented. The findings of the study underline the significant seasonal differences between higher and lower latitude stations which is in line with the findings of previous studies. Moreover, we attempt to correlate spread F activity and Travelling Ionospheric Disturbances (TID) over Digisondes, identified on GPS detrended TEC maps from the DRAWING-TEC project at 10-min resolution for 2017. The similarity in spread F activity at nearby stations supports the hypothesis that spread F development over nearby stations can be attributed to common TID activity affecting both stations.