Connections Between Stratospheric GWs, the Polar Vortex, and MSTIDs From Longitudinally Distinct Regions During Nine Arctic Winters

Abstract

Midlatitude medium‐scale traveling ionospheric disturbances (MSTIDs) are a common source of ionospheric variability that may influence GNSS‐based positioning and can disrupt HF‐communication channels. Here, we present a comprehensive nine‐winter analysis (2014–2023) that establishes a robust connection between stratospheric gravity waves (GWs) in the polar night jet (PNJ) region and daytime MSTID amplitudes over North America and Europe. Using atmospheric infrared sounder satellite observations, MERRA‐2 wind reanalysis, and GNSS‐derived differential TEC data, we show positive correlations between wintertime stratospheric GWs located in the PNJ and MSTIDs over North America and Europe. The positive correlations arise from sub‐seasonal variations, rather than short‐period fluctuations or solar or geomagnetic drivers. Correlations are elevated for MSTIDs from 7 to 15 LT over midlatitude Europe and from 7 to 20 LT over midlatitude North America and are low at other times. This local time range corresponds to when the thermospheric diurnal tide exhibits poleward flow, which is known to facilitate equatorward propagation of higher‐order GWs.