Observing Mesospheric Gravity Waves with NASA’s AWE Mission and Correlating to GNSS TEC Maps

The Atmosphere Waves Experiment (AWE) is a NASA mission launched on November 9, 2023, and installed on the International Space Station (ISS). Its primary goal is to detect and characterize atmospheric gravity waves (AGWs) by measuring Earth’s mesospheric hydroxyl (OH) airglow with its key instrument, the Advanced Mesospheric Temperature Mapper (AMTM). Since its deployment, AWE has been quantifying the seasonal and regional variability of AGWs, investigating their occurrence and potential sources, and enabling the assessment of their broader impact on the atmosphere by comparing measurements at different altitudes by other instruments. AWE has collected extensive imagery and temperature data capturing distinct mesospheric phenomena, including mesospheric bores, signatures of a hurricane, and instability- and convection-driven disturbances. These observations are now publicly available for the first several months of the mission. In this work, we compare AWE’s dataset to total electron content (TEC) maps derived from GNSS data processed by the System for Rapid Analysis of Ionospheric Dynamics (S-RAID) (Inchin et al., 2023), which analyzes data from approximately 2,700 stations across the continental United States (CONUS). S-RAID applies common bandpass filters to isolate traveling ionospheric disturbances (TIDs) with periods shorter than two hours. By comparing AWE’s measurements at the approximate OH airglow height of 87 km with the GNSS data at an average ionospheric pierce point (IPP) of 300 km, we identify wave parameters and potentially determine which signatures correspond to upward-propagating gravity waves. These signals, in turn, can be traced back to various tropospheric sources, such as those mentioned above.