Characteristics of solar flares associated with ground level enhancement events

We conduct a statistical analysis on 76 ground level enhancement (GLE) events to examine the characteristics of their associated solar flares. Our analysis reveals that GLE-associated flares predominantly occur within the longitude range of 20^∘–100^∘ west and belong to higher optical and soft X-ray flare classes, with 84% being X-class. The average flare longitudes for GLEs with increase rates above 100% and 10% are found to be 53.67^∘ ± 15.31^∘ and −59.18^∘ ± 8.04^∘, respectively, with a concentration near 55^∘ west longitude for high-intensity GLEs. Statistical timing analysis shows that 69% of GLE events commence after the associated flare peaks, with an average delay of 17.18 ± 7.06 minutes. These findings underscore the impact of solar flare location and intensity on GLE production and highlight the role of interplanetary magnetic field structures in guiding energetic particle transport toward Earth. The results further suggest that both flare-driven and CME-driven acceleration mechanisms play a role in GLE initiation, with particle transport conditions influencing the observed timing relationships.