Short- and long-wavelength TIDs generated by the Great American Eclipse of 21 August 2017 | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

Twitter

Aller au compte twitter

  Short- and long-wavelength TIDs generated by the Great American Eclipse of 21 August 2017

Type de publication:

Journal Article

Source:

JGR-Space Physics (Soumis)

Mots-clés:

21 August 2017, ionosphere, Solar Eclipse, TEC, USA

Résumé:

On the 21st August 2017 the eclipse shadow drastically changed the state of the ionosphere over the USA. This effect on the ionosphere is visible in the total electron content (TEC) measured by GNSS. The shadow moved with the supersonic speed of ~1000 m/s over Oregon to ~650 m/s over South Carolina. In order to exhaustively explore the ionospheric signature of the eclipse, we use data of total electron content (TEC) from ~3000 GNSS stations seeing multiple GPS and GLONASS satellites to visualize the phenomena. This tremendous dataset allows high-resolution characterization of the frequency content and wavelengths -using an omega-k analysis based on 3D Fast-Fourier-Transform (FFT)- of the eclipse signature in the ionosphere in order to fully identify traveling ionospheric disturbances (TIDs). We confirmed the generation of TIDs associated with the eclipse including TIDs interpreted as bow waves in previous literature. Additionally we revealed, for the first time, short (50-100 km) and long (500-600 km) wavelength TIDs with periods between 30 and 65 min. The sources of the revealed short wavelength TIDs are co-located with the regions of stronger gradient of EUV related to sunspots. Our work confirms and describes the physical properties of the waves observable in the ionosphere during the Great American Eclipse.