This can also be useful in unpredictable ways. One is the North Korean nuclear test a couple of years back[1]. "The blast generated infrasonic waves that propa

This can also be useful in unpredictable ways. One is the North Korean nuclear test a couple of years back[1]. "The blast generated infrasonic waves that propagated all the way to the upper atmosphere causing small variations in the density of electrons there. By analyzing the signals from GPS satellites collected at ground-based monitoring stations in South Korea and Japan, scientists [...] confirmed the ionospheric disturbance generated by the North Korean test." [1] http://gpsworld.com/researchers-see-ionospheric-signature-of-north-korean-nuclear-test/ http://gpsworld.com/researchers-see-ionospheric-signature-of...