Abstract

On December 14, 2020, a total solar eclipse occurred whose shadow cone projected over part of South America. Its effect on critical ionospheric frequencies variability is analysed, considering two stations with similar geographical latitudes and a 95% obscuration percentage: Chilla acute accent n (36.6 degrees S, 72.0 degrees W), in Chile, and Bahi acute accent a Blanca (38.9 degrees S, 62.2 degrees W), in Argentina. A comparison of the ionospheric response to the eclipse is made with quiet time daily values and the IRI-2016 model. Results indicate that the greatest eclipse impacts are obtained in foE and foF1, with similar to 31% and similar to 40% of maximum reductions, respectively. Alternatively, weak disturbances are observed in the foF2 case (<20%). The recombination coefficients were calculated for the E-layer and F1-layer with values of alpha similar to 10(-9) cm(3) s(-1) and for F2-layer with values in beta similar to 10(-4) s(-1), similar to previous studies. Longitudinal differences between both ionospheric stations are very small for the F1-layer (similar to 11%), but a much larger variability is found at F2-layer critical frequencies (similar to 20%). These results suggest different plasma diffusion processes at high altitudes in the different locations that require further investigation in future studies. (C) 2021 COSPAR. Published by Elsevier B.V. All rights reserved.