Predicting Solar Flares by Data Assimilation in Avalanche Models. I. Model Design and Validation

TL;DR

This paper investigates applying 4D-VAR data assimilation to solar flare prediction using avalanche models, demonstrating it can produce initial conditions that replicate energy release time series, advancing flare forecasting capabilities.

Contribution

It introduces the novel application of 4D-VAR data assimilation to avalanche models for solar flares, showing promising results in reproducing flare energy series.

Findings

4D-VAR successfully reproduces synthetic flare energy time series.

The approach provides optimal initial conditions for flare prediction.

Results are a step toward real flare forecasting.

Abstract

Data assimilation techniques, developed in the last two decades mainly for weather prediction, produce better forecasts by taking advantage of both theoretical/numerical models and real-time observations. In this paper, we explore the possibility of applying the data-assimilation techniques known as 4D-VAR to the prediction of solar flares. We do so in the context of a continuous version of the classical cellular-automaton-based self-organized critical avalanche models of solar flares introduced by Lu and Hamilton (Astrophys. J., 380, L89, 1991). Such models, although a priori far removed from the physics of magnetic reconnection and magneto-hydrodynamical evolution of coronal structures, nonetheless reproduce quite well the observed statistical distribution of flare characteristics. We report here on a large set of data assimilation runs on synthetic energy release time series. Our results indicate that, despite the unpredictable (and unobservable) stochastic nature of the driving/triggering mechanism within the avalanche model, 4D-VAR succeeds in producing optimal initial conditions that reproduce adequately the time series of energy released by avalanches/flares. This is an essential first step towards forecasting real flares.