Volcanic eruption effects over the upper ionosphere

ARGELIA H. C. DE RAGONE; AMALIA N. F. DE MANZANO; ANA G. ELIAS; MARTA ZOSSI DE ARTIGAS

Concepcion

Congreso; 6ta COLAGE, Conferencia LatinoAmericana de Geofísica Espacial; 2001

ALAGE, Asociacion LatinoAmericana de Geofisica Espacial

Nuclear detonations, strong earthquakes and volcanic eruptions can trigger acoustic-gravity waves in the Earth atmosphere. These waves can disturb surface pressure as well as ionospheric parameters as already detected by other authors. In this work, variations of ionospheric parameters measured in Argentina and Chile during eruptions of volcanoes located in the Andes Cordillera, were analyzed. The response to volcanic eruptions of magnitude greater or equal to 2 during 1957 and 1986, of the critical frequency foF2, and the F layer virtual height, h´F, hourly data for quiet magnetic activity, was studied. In some cases, during the eruption days, a decrease in foF2 amplitude variation and an increase in h’F can be noticed respect to previous days. This behavior, similar to that found in Manila by other authors in response to the Mount Pinatubo eruption, may be interpreted as the ionosphere response to gravity waves propagation originated by volcanic eruptions.