VARIATIONS OF PLASMA PARAMETERS OF THE UPPER IONOSPHERE AFTER THE UNDERGROUND NUCLEAR DETONATIONS

  1. Pushkov institute of terrestrial magnetism, ionosphere and radio wave propagation, RAS

Observations of the ionosphere disturbances during the underground nuclear explosions (UNE) at various
test sites from the satellite Cosmos-1809 at an altitude of about 960 km [Kostin and Murashev, 2002] are pre-
sented. Relaxation processes in the Earth’s crust after UNE can be associated with the mechanisms of stress
before earthquakes. During joint verification experiments to monitor UNE at the Nevada Test Site (NTS) on
August 17, 1988 and at the Semipalatinsk Test Site (STS) on September 14, 1988 dynamics of the ionospheric
plasma parameters perturbations (within 3 days) over the polygons and magnetoconjugated area were discussed.
Physical mechanisms explaining the different types of observed perturbations were proposed on the example
of registration experience of TEXARKANA conducted on 10.02.1989 at NTS, when the satellite was near the
magnetic zenith at the time of the explosion. These perturbations were compared with those on the same day
from Pacific Ocean Harry typhoon and Indian Ocean Kirryly one [Isaev et al, 2010]. Superposition of sudden
ionospheric disturbances (SID) and the disturbances after UNE were considered on the example of the record-
ing experience at STS on 16.10.1987. In this experiment highly dispersed signal EMI UNE reflected from the
ionosphere of the other hemisphere was found due to the accompanying ground-based ULF-ELF observations
[Belyaev, 2003]. The experiment on the Moruroa atoll on 21.11.1990, carried out during the anomalous condi-
tion of the upper ionosphere, where the density was lowered by two orders of the median values showed that
the lithospheric source can be successfully identified from the ionospheric satellite in this case too.