Capturing atmospheric dynamics with cross-correlation functions: Insights from infrasound propagation during the April 8, 2024 Solar Eclipse

The Earth’s atmosphere is a highly dynamic system influenced by periodic and transient phenomena, such as diurnal cycles, seasonal changes, thunderstorms, and solar eclipses. This variability is especially pronounced in the Atmospheric Boundary Layer (ABL), where rapid fluctuations in temperature and wind speed/direction significantly affect the propagation of infrasound waves. Traditional numerical models often fail to fully capture this complexity due to the ABL’s inherent spatiotemporal variability. In this study, we employed cross-correlation functions (CCFs) to analyze the atmospheric response to infrasound waves. A 24-h experiment conducted at Southern Methodist University, Dallas, Texas, from April 8 to 9, 2024, during diverse atmospheric conditions—including a total solar eclipse—generated a unique dataset. Chirp signals emitted by a fixed infrasound source were recorded by an array of sensors at various distances, allowing detailed CCF analysis of source-receiver signals. The results revealed significant changes in signal travel time and amplitude, particularly during the solar eclipse, highlighting the ABL's transient response. These findings demonstrate that CCFs effectively capture the dynamic evolution of the atmosphere, providing insights that surpass the capabilities of numerical models. This study underscores the importance of experimental techniques in advancing infrasound propagation research and atmospheric studies.