Conjugate Sporadic-E measurements

During an equatorial campaign called COPEX (Conjugate Point Equatorial Experiment) ionosondes at a pair of conjugate stations in Brazil were operated for 2 months in 2002. One expected the sporadic-E (Es) layers to be rather similar at the conjugate locations. However, there were significant differences in the Es, particularly in the part of the Es trace that extends above the blanketing frequency. Considerations of the ambient conditions at the conjugate locations indicate that relatively small differences in parameters such as the tidal winds, electric fields, and background density gradients can significantly affect the structuring of the Es layer.