The Second LHAASO Collaboration Conference in 2026 & The Academic Symposium for the 10th Anniversary of the LHAASO collaboration

LHAASO (4410 m a.s.l., Daocheng, Sichuan, China) is a new-generation hybrid ground-based detector array composed of three sub-arrays: KM2A, WCDA, and WFCTA, among which KM2A is used to measure electromagnetic particles and muons in cosmic ray air shower events. In the shower mode of the KM2A array, a shower event is recorded when the trigger condition is satisfied, i.e., at least 20 EDs or MDs are fired within a 400 ns time window. During thunderstorms, the noise trigger recorded by the detector will increase, primarily attributed to intense electromagnetic radiation and precipitation, which consequently elevates the shower event rate in LHAASO-KM2A. In this work, using the CORSIKA and G4KM2A packages, the relationship between the noise-level and shower rate variation in LHAASO-KM2A is simulated. Meanwhile, the noise is subtracted from each shower event by means of re-triggering.