Replication Data for Ionospheric Effects during the Total Solar Eclipse over Southeast Asia-Pacific on 9 March 2016

We report the results of our experimental investigation on a number of ionospheric effects that were observed during the total solar eclipse over the Southeast Asia-Pacific region on 9 March 2016. In particular, here we discuss a set of experimental observations that reveal a rapid uplift of the ionospheric F-layer during the eclipse, and prompt reduction of ionospheric plasma density in the areas around the eclipse totality. Data from ionosonde measurements at Biak (in eastern part of Indonesia) and Guam (in the Pacific) indicate an upward vertical drift velocity in the range of 21-40 m/s in the ionospheric F-region during the eclipse. Over Biak, foF2 decreased from 10 MHz to 6 MHz (a 40% reduction) during the eclipse. Meanwhile, foF2 over Guam during the eclipse was suppressed for a few hours; lower than the 7-day average normal level by 3 MHz. A comparison with the total electron content (TEC) data from MIT Haystack Observatory's Madrigal Database further confirms the findings from these ionosonde measurements. In addition, observational data from an HF radio link between Biak and Manado (~1300 km apart, cutting across the eclipse totality trajectory) also indicate that the D-region ionosphere had diminished considerably during the solar eclipse. We attribute these eclipse-related ionospheric effects to the interruption of solar photoionization within the eclipse totality, and to the consequential disruption of the background ionospheric current by the localized ionospheric density reduction --- which leads to a build-up of polarization electric field that gives rise to an upward vertical plasma drift.
We report some key findings from our experimental observations and data analyses on a number of ionospheric effects that had occurred during the total solar eclipse over the Southeast Asia-Pacific region on 9 March 2016. Specifically, here we present the observations of traveling ionospheric disturbances (TIDs) likely to have been caused by the passage of the total solar eclipse in the region. Moreover, we also discuss the observed spatio-temporal pattern of changes in the total electron content (TEC) distribution in the areas traversed by the eclipse totality. Signatures of eclipse-related TIDs were seen in the Doppler signals from ionosonde measurements at Guam, and in the TEC perturbation (TECP) signals from several GPS receiver stations in eastern part of Indonesia. These TIDs were observed at F-region heights with a period of 30-45 minutes, Doppler velocity amplitude of 15 m/s, and TEC fluctuations of 0.3-0.4 TECU. In addition to the TID signatures, the data from GPS receiver stations also show that the level of absolute TEC was significantly affected by the passage of the eclipse. TEC reductions in the range of 10-14 TECU were observed over the eastern part of Indonesia and over Guam. In the surveilled areas, the TEC reduction due to the solar eclipse was generally found to be more prominent at the coordinate points located further east --- closer to the point of greatest eclipse duration in the middle of the Pacific. We posit that the variability in the TEC reduction (as well as the non-uniformity in the TID wave patterns) during the eclipse was caused in part by the varying lunar shadow speed at different parts of the eclipse trajectory.