Study on Four-Dimensional Evolution of Concentric Traveling Ionospheric Disturbances After Falcon 9 Rocket Launch Using Ionospheric Tomography

Abstract

The ionospheric disturbances induced by the Falcon 9 rocket launch on 17 January 2016 were reconstructed by threedimensional computerized ionospheric tomography (3DCIT) using observations from the North American GNSS networks. The results showed that concentric traveling ionospheric disturbances (CTIDs) occurred ~18 minutes after the rocket launch and were remarkable at 200-300 km altitudes. The vertical phase velocities of the CTIDs were consistent with the inclinations of the U-shaped structures. At specific azimuth directions of 350°, 30°, and 105°, the estimated vertical phase velocities between 100 km and 200 km altitudes were ~222.2 m/s, ~208.3 m/s, and ~242.4 m/s, respectively. When the CTIDs propagated upward to 400-500 km altitudes, their vertical velocities increased to ~566.7 m/s, ~966.7 m/s, and ~944.4 m/s. CTIDs traveling northward (azimuths 350°, 30°) had periods of ~11 minutes. At 200 km and 300 km altitudes, their horizontal phase velocities were ~309.9-323.3 m/s and ~309.4-330.9 m/s, respectively, with horizontal wavelengths of ~204.5-213.4 km and ~204.2-218.4 km. In contrast, CTIDs propagating eastward (azimuth 105°) displayed a period of ~15 minutes. At 200 km and 300 km altitudes, their horizontal phase velocities were ~223.2 m/s and ~241.1 m/s, respectively, with horizontal wavelengths of ~200.9 km and ~217.0 km. These CTIDs propagation characteristics agreed well with the theory of gravity waves (GWs).