Distant Storms Can Affect Seismic Noise Crustal Monitoring

Abstract Using seismic noise interferometry to monitor the Earth's interior relies on continuous seismic wavefields produced by stable, invariant sources. In numerous applications, this condition is relaxed, arguing that secondary scattering effects render the late coda source independent. Using an 800‐km aperture seismic array in southwestern China, we identify strong teleseismic body waves (P, PP, PKPbc) embedded in the noise correlation functions in the secondary microseism frequency band (5–10 s) that exhibit seasonal variations correlating with changes in ocean wave heights at distant source regions. We demonstrate that these body wave arrivals generate cross‐talk artifacts that distort both ballistic and coda wavefields. Our findings challenge the assumption that late coda waves are source‐independent and highlight the need to account for body wave interference from distant storms to ensure reliable interpretations in ambient noise‐based studies.