NSF Award
0451265
The possible connection between mesoscale tropospheric storms and ionospheric spread-F events is investigated using fifty years of ionosonde data, and using extensive incoherent scatter radar and microbarograph data. The project aims to determine by correlative testing whether there is a statistically significant association between periods of Spread-F observation and concurrent, identifiable mesoscale disturbances in the tropical troposphere. The electric field strength and direction as well as ion drift velocities will be determined for associated events when possible, and an attempt will be made to ascertain the relationship between the location and time of storms and the associated onset of the F-region ionospheric regularities. This study attempts to conclusively identify or exclude gravity waves generated by storms as a likely source of the density fluctuations, or Kelvin-Helmholtz instabilities, thought to be the precursor to F-region instabilities that generate GPS scintillation events.
