Low latitude ionospheric TEC response to the solar flares during the peak of solar cycle 24

We describe the newly discovered response of differential vertical total electron content (DVTEC) in the low-equatorial latitude ionosphere to the solar flares during the peak of solar cycle 24 i.e., the year 2014. GPS TEC data for the existing investigation has been acquired from the international GNSS services network station in Bangalore, India (geomagnetic latitude 4.58oN). For the year 2014, we inspected five X-class solar flares, forty-nine M-class solar flares, and three hundred ninety-six C-class solar flares in the current study. To ascertain the relationship between ADVTEC and the AX-ray and AEUV fluxes, the two main ionizing radiation fluxes during flare events are used. Additionally, to identify electron density change in the ionosphere due to solar flares, we used two well-known methodologies, the baseline method and the mean method. The baseline method provides a better correlation between ADVTEC and AX-ray for X-, M-, and C-class flares. For M- and C- class flares, both methods do not show any meaningful correlation. The Solar disc location effect shows an enhanced (0.573) correlation between ADVTEC and AX-ray*cos (CMD) for the X-class flares, whereas for M- and Cclass flares, no significant change was observed, which indicates feeble or no CMD effect for lower class solar flares while it is opposite for X-class flares. Here we suggest that the high solar activity, and location of the observation station to the EIA trough region might be the possible reason for the observed results.(c) 2023 COSPAR. Published by Elsevier B.V. All rights reserved.