Ionospheric responses to the 21 August 2017 great American solar eclipse - A multi-instrument study

Publication date: Available online 16 September 2019Source: Advances in Space ResearchAuthor(s): G. Uma, P.S. Brahmanandam, V.K.D Srinivasu, D.S.V.V.D Prasad, V. Sai Gowtam, S. Tulasi Ram, YH ChuAbstractIonospheric responses to a total solar eclipse occurred on 21 August 2017 over the US region is reported. Ground-based GPS total electron content (TEC) data along with ground (Millstone Hill Observatory (MHO) and digital ionosondes) and space-based measurements (COSMIC radio occultation, RO, technique) allowed us to identify eclipse associated ionospheric responses. TEC data at ∼200, ∼300, and ∼400 N latitudes from west to the east longitudes show not only considerable depression, but also show wavy nature in TEC both in the path of totality and away from it, exclusively on the day of eclipse. Interestingly, the observed depressions are associated with lesser (higher) magnitudes at stations over which the solar obscuration percentage was meager (significant), a clear indication of bow wave-like features. The MHO observes a 30% reduction in F2-layer electron densities between 180 and 220 km on eclipse day. Ionosonde- scaled parameters over Boulder (40.40N, 1000E) and Austin (30.40N, 94.40E) show a significant decrease in critical frequencies while an altitude elevation is seen in virtual heights of the F-layer only during the eclipse day and that decreases are associated with wave-like signatures, which could be attributed to eclipse-generated waves. The estimated vertica...

Source: Advances in Space Research - September 18, 2019 Category: Science Source Type: research