Measurements and Modeling of Total Solar Irradiance in X-Class Solar Flares

TL;DR

This study measures and models the total solar irradiance during X-Class solar flares using NASA's TIM data, establishing an empirical relationship with VUV irradiance to estimate flare energy output.

Contribution

It introduces a robust algorithm for analyzing TSI variations during solar flares and links TSI measurements with VUV models to estimate flare radiative energy.

Findings

Successful measurement of TSI changes during X-Class flares.

Established empirical relationship between VUV irradiance and TSI.

Enabled estimation of flare bolometric energy from VUV data.

Abstract

The Total Irradiance Monitor (TIM) from NASA's SOlar Radiation and Climate Experiment (SORCE) can detect changes in the Total Solar Irradiance (TSI) to a precision of 2 ppm, allowing observations of variations due to the largest X-Class solar ares for the first time. Presented here is a robust algorithm for determining the radiative output in the TIM TSI measurements, in both the impulsive and gradual phases, for the four solar ares presented in Woods et al. (2006), as well as an additional are measured on 2006 December 6. The radiative outputs for both phases of these five ares are then compared to the Vacuum Ultraviolet (VUV) irradiance output from the Flare Irradiance Spectral Model (FISM) in order to derive an empirical relationship between the FISM VUV model and the TIM TSI data output to estimate the TSI radiative output for eight other X-Class ares. This model provides the basis for the bolometric energy estimates for the solar ares analyzed in the Emslie et al. (2012) study.