Ionospheric effects during the total solar eclipse over South-East Asia-Pacific on 9 March 2016, Part 2: Total electron content reduction and fluctuation patterns

We report our observations and data analysis of ionospheric effects during the total solar eclipse over the South-East Asia-Pacific region on 9 March 2016. Here we present observations of spatio-temporal changes in the total electron content (TEC) distribution in the areas traversed by the eclipse. TEC reductions of 10-14 TECU were observed over the eastern part of Indonesia and over Guam. In the surveilled areas, TEC reductions due to solar extreme ultraviolet (EUV) obstruction during the eclipse were more prominent at coordinate points located further east, closer to the point of greatest eclipse duration in the middle of the Pacific. In addition, we also discuss observations of medium-scale traveling ionospheric disturbances (MSTIDs) associated with the passage of this solar eclipse. Signatures of eclipse-related TIDs were seen in the TEC perturbation (TECP) signals from several GPS receiver stations in eastern part of Indonesia and in the Doppler signals from ionosonde measurements at Guam. These MSTIDs were observed at F-region heights with a period of 30-45 min, Doppler velocity amplitude of 15 m/s, and TECP fluctuations of 0.3-0.4 TECU.