Solar flare evolution model for operational users

A solar flare evolution prediction model has been developed and placed into operations to mitigate flare-related risks to operational systems. The GOES 0.1-0.8 nm X-ray background flux is first determined and the residual flux is used to create a flare index value. The flare index is useful for determining the relative characteristics of a flare separate from its background, for comparison with other flares, and for determining flare initiation. Within the first five minutes of flare initiation, the flare evolution model predicts the flare rise, timing and magnitude of the peak fluxes, decay to half maximum, and termination at background levels. Based on the rise time, a flare is quantitatively categorized as small, medium, or large based on the absolute value of the flare index value and this enables the selection of a flare model shape. Using the convolution of Gaussian and quadratic functions for the modeled flare, the integral of the flare area (magnitude and duration) quantifies its integrated energy content which can be related to the flare’s geoeffectiveness. A description of the flare evolution prediction model and its development for operations is presented. The solar flare evolution model and the operational system behind it is compliant with ISO 21348 “Process for Determining Solar Irradiances.”