9 March 2016 Solar Eclipse Effects F2 Layer Peak Electron Density at Conjugate Points over Southeast Asia Region

Abstract

In this paper, the effect of March 9, 2016 solar eclipse on the F2 layer peak electron density (NmF2) at conjugate points in Southeast Asia is presented. NmF2 is calculated from the F2 layer critical frequency (foF2) that is manually scaled from three ionosonde stations in Southeast Asia region. Two ionosonde stations are in Thailand, namely Chiang Mai $(18.76^{\circ} N, 98.93^{\circ} E$, Dip $12.7^{\circ} N)$ and Chumphon $(10.72^{\circ} N, 99.38^{\circ}$E, Dip $3.2^{\circ} N)$. One station is in Indonesia, namely Kototabang $(0.2^{\circ}\mathrm{S}, 100.32^{\circ}$E, Dip $10.1^{\circ} S)$. These ionosonde stations are located at conjugate points in Southeast Asia. The daily interquartile range (every 15 minutes) of NmF2 data from 4$^{th}$ March to 15$^{th}$ March 2016 were analyzed the NmF2 variations during before and after the solar eclipse day on 9$^{th}$ March 2016. Besides, the monthly median, the upper boundary and lower boundary of NmF2 compared with the observed ones were used for analyzing the anomalous variations. The results of this study indicate that the NmF2 value increases during 2 days before and after the eclipse day while it decreases on solar eclipse day for all 3 stations.