Ingestion of GNSS‐Derived‐TEC Into NeQuick 2 Model Over South America

Abstract This study examines the ingestion of total electron content (TEC) data from a network of ground‐based Global Navigation Satellite System (GNSS) receivers into the NeQuick 2 model, providing a benchmark for evaluating the cost‐effectiveness of GNSS data ingestion for near‐real‐time ionospheric specification. A significant reduction in root mean square error (RMSE) between NeQuick 2 outputs and GNSS‐derived TEC was observed across various test stations, including those located at mid‐latitudes. During geomagnetically quiet periods, the performance difference between using 35 and 166 GNSS stations was less than 1%, while a similar trend, less than 2% difference was observed during disturbed periods with 34 and 177 stations, respectively. These findings highlight the importance of the spatial distribution of GNSS receivers in enhancing the model's accuracy, particularly over regions with complex ionospheric dynamics. Diurnal variations in vertical TEC (vTEC) over the test locations showed remarkable improvement during geomagnetic disturbances, with enhancements ranging from 37% to 68% in the low‐latitude region. Additionally, comparisons between NeQuick 2‐derived plasma frequencies and digisonde observations demonstrated strong agreement in the 100–200 km altitude range, with average correlation coefficients of 0.97 and 0.95 at São Luís (2.58°S, 44.20°W), 0.93 and 0.55 at Boa Vista (2.83°N, 60.70°W), and 0.88 for both conditions at Campo Grande (20.40°S, 54.50°W) during quiet and disturbed periods, respectively. The lower correlation observed at Boa Vista during disturbed conditions may be attributed to limited data ingestion coverage in the Northern Hemisphere.