On the magnetospheric effects of experimental ground explosions observed from AUREOL-3

Abstract

A new analysis is described for the published data from the M ASS A active experiments held in 1981-1983 in the USSR. These tests were aimed to simulate earthquake effects in the magnetosphere and ionosphere using surface chemical explosions. Measurements in the magnetosphere above the explosions were made from the AUREOL-3 satellite (Galperin et al1985a1985b). ELF/VLF noises were excited within an altitude range from 410 km to ≈ 2000 km along the Explosion plasma Flux Tube (EFT), based on the .E-region above the explosion point (L ≈ 1.5). During the MASSA-1 experiment, at L ≈ 1.3, before the EFT crossing, 5 minutes after the explosion at L = 1.5, a strong upward moving MHD-impulse was registered with a sharp front. The front was accompanied by excited ion sound waves. Indirect arguments are presented for the origin of the impulse within the EFT, its bouncing and accompanied cross-L drift to, and then trapping at L = 1.3. The effects observed suggest the existence of a natural MHD-impulse generator and/or its power amplifier located in the middle atmosphere not higher than 70 km. It generates/amplifies the electromagnetic response in the magnetosphere and ionosphere. It is suggested that the form of electric discharges in the middle atmosphere known as red sprites or blue jets can serve the role of the natural generator/power amplifier for the effects in the ionosphere and magnetosphere observed in the M ASS A experiments. If real, it can be speculated that similar amplification effects through atmospheric electrical discharges could play a role in the generation of some earthquake precursor effects observed in the magnetosphere and ionosphere.