Polarimetry Studies of Ionospheric Modification by Rocket boosters

High altitude releases of certain molecules in booster rocket exhausts are known to deplete electron concentration in the ionosphere dramatically. These effects are exhibited in recent Faraday rotation measurement for the HEAO-C launch from Cape Kennedy on September 20, 1979 and the NOAA-B launch from Vandenberg on May 29, 1980, in which total electron content drop-out responses to the booster rockets are evident. The polarimetry experiments and data for these nocturnal launches are presented, discussed, and analyzed to obtain time profiles of total electron content (TEC) associated with three different satellite-to-receiver raypaths. Calculations of the booster rocket effect are carried out in detail for the HEAO-C case in an attempt to theoretically simulate the experimental results for the early-time TEC depletion effect from the booster rocket. The calculational model includes a full, three-dimensional integration of the rocket exhaust effect, in which rocket exhaust expansion is treated as thermalized, mutual diffusion in the non-uniform ambient background atmosphere. Results are discussed, and future directions are indicated. (Author)