Oceans are a major source of waves in the thermosphere

Recent theoretical analysis by Godin et al. (2015) led to the suggestion that infragravity waves (IGWs, i.e., surface gravity waves in the ocean with periods longer than 30 s) can radiate acoustic-gravity waves (AGWs) and account for a significant part of the wave activity observed in the thermosphere with periods between about 5min and 3 h. In this paper, we report a strong experimental demonstration of thermospheric waves being driven by the ocean using data from two Deep-ocean Assessment and Reporting of Tsunamis stations located off the US East Coast and Dynasonde radar system located at Wallops Island, Virginia. Over a 9month observation period, variations of IGW and AGW spectral amplitudes demonstrate large, statistically significant correlation in a broad range of frequencies (0.2-3.2mHz) and altitudes (140-190 km). Peak correlation values (similar to 0.43) indicate that waves radiated by the ocean represent a major constituent of thermospheric wave activity.