Comparison of the simulated amplitude scintillation indices (circles) with the empirical data (squares) for the low latitude region over Africa, the Atlantic Ocean, and South America. As a reference to the possible plasma bubble shapes, the background image shows the atmospheric emission radiance obtained from the GOLD mission data. The green vectors represent the gradient values of the mask extracted from the GOLD images and the black vectors correspond to the Swarm NeGIX index.