||Possible shear instability in the daytime midlatitude sporadic-E observed with InSAR and GPS-TEC
Maeda, Jun ,
Suzuki, Takato Furuya, Masato ,
A coordinated observation of GPS total electron content (TEC) and space-borne interferometric synthetic aperture radar (InSAR) has been conducted to reveal both the large- and small-scale plasma structures of daytime midlatitude sporadic-E (Es). Both observations are used for the direct imaging of the plasma patches. GPS-TEC observations have shown a common frontal shape of Es elongated typically in the east-west (E-W) direction, while an interferogram derived from InSAR observation have revealed the small-scale (fine) structure of Es. Small-scale patches are aligned in the E-W direction which is the same azimuthal direction of dominant large-scale frontal structure. We speculate that the Kelvin-Helmholtz instability with the vertical shear of meridional winds is considered to be the most likely candidate for the generation mechanism of the small-scale plasma patches aligned in the zonal direction.