Equatorial plasma bubbles studied using African slant total electron content observations

Equatorial plasma bubbles (EPBs) are field-aligned depletions of F-region ionospheric plasma density that grow from irregularities caused by the generalized Rayleigh–Taylor instability mechanism in the postsunset equatorial sector. Although they have been studied for some decades, they continue to be an important subject of both experimental and theoretical investigations because of their effects on trans-ionospheric radio communications.In this work, calibrated data of slant total electron content (sTEC) taken every 10 min from EGNOS System Test Bed Brazzaville (Congo), Douala (Cameroon), Lome (Togo) and N’Djamena (Chad), and International GNSS Service Ascension Island, Malindi (Kenya), and Libreville (Gabon), stations are used to detect plasma bubbles in the African equatorial region during the first 6 months of 2004. To identify these irregularities, the trend of every curve of sTEC against time is subtracted from the original data. The size of the EPBs is estimated by measuring its amplitude in the de-trended time variation of sTEC.