Total Electron Content (TEC) is a pivotal parameter in ionospheric physics and space weather research, offering critical insights into the ionospheric conditions of a region. Despite its significance, Sub-Saharan Africa, including Malawi, faces substantial challenges due to a sparse network of geodetic stations needed for comprehensive atmospheric modeling. This paper presents an in-depth characterisation of TEC over Malawi using high-rate Global Positioning System (GPS) observations. The study leverages data from Continuously Operating Reference Stations (CORS) and campaign measurements from short-term GPS receiver deployments across diverse locations within the country. The analysis reveals notable variations in TEC, influenced by seasonal changes, latitude, and the elevation of geodetic receivers. Notably, the findings indicate elevated TEC values during midday hours relative to other periods, with higher TEC recorded in elevated regions compared to lower-lying areas. The study further highlights that TEC exhibits increased temporal variation during the wet season, with pronounced fluctuations around midday local time. These findings not only enhance an understanding of TEC dynamics in Malawi but also underscore the critical need for more extensive studies on geomagnetic influences and quiet days to fully elucidate TEC dynamics.

Keywords: TEC modelling, GPS observations, Malawi