Total Electron Content Modelling Over Malawi Using GPS Observations

Total Electron Content (TEC) is a crucial parameter in ionospheric physics and space weather studies as it allows researchers to gain insights into ionospheric conditions for a specific area. Despite this importance, Sub-Saharan Africa faces challenges due to the limited number of geodetic stations for modelling such weather phenomena. This paper focuses on modelling TEC over Malawi using Global Positioning System (GPS) observations. The study utilises data from Continuously Operating Reference Stations (CORS) and campaign measurements from short-term GPS receiver occupations in multiple locations. The analysis reveals that TEC exhibits variations based on season, latitude, and elevation of the geodetic receiver. Notably, the findings indicate increased TEC values during midday hours compared to other periods, with regions of higher elevations displaying greater TEC than low-lying areas. The study also highlights that during the wet season, there is more variation in TEC throughout the day and across seasons, particularly around midday in local time. Furthermore, statistical analysis was conducted to evaluate the relationship between the estimated GPS-TEC and International Reference Ionosphere (IRI)-TEC, revealing a strong agreement in seasonal and diurnal trends. Furthermore, statistical analysis was conducted to evaluate the relationship between the estimated GPS-TEC and International Reference Ionosphere (IRI)-TEC, revealing a strong agreement in seasonal and diurnal trends. Solar and geomagnetic activity over Malawi was also evaluated. The study revealed that the lack of significant geomagnetic storms, combined with stable solar flux, suggests that daily TEC variations are primarily controlled by solar ionisation. While uncovering these characteristics in TEC over Malawi, the study underscores the need for further investigation to explore the intricate realms of geomagnetism and quiet days in shaping TEC dynamics.

Keywords: TEC modelling, Geodetic station, GPS observations, Malawi, CORS