Composition changes during geomagnetic disturbances

MANSILLA, GUSTAVO A.; ZOSSI ARTIGAS MARTA

Ciudad Autónoma de Buenos Aires

Congreso; Eleventh Latin American Conference on Space Geophysics; 2018

Asociación Latinoamericana de Geofísica Espacial

disturbances in technological systems which depend on transionospheric communications, in the static or dynamical positioning with satellites, among others.Increases or decreases of the Total Electron Content TEC and/or peak electron density of the F2 layer NmF2 with respect to quiet magnetic conditions can be observed during geomagnetic storms. It is well known that decreases in TEC or NmF2 (called negative disturbances) are correlated with an increase in the N2/O ratio, which is attributed to an increase in the molecular nitrogen N2 and practically no change in the atomic oxygen O. Using the DE-2 satellite data at F2 region heights, we analyze the changes observed in the molecular nitrogen and atomic oxygen densities during storms occurred in 1982. The results show that both N2 and O increase during storm periods but N2 increase more than O. An order of magnitude of the relative deviations has been calculated. Although data used are rather old, they are useful because they are one of the few in situ measurements that have been made. That permits to study with precision the ionospheric and thermospheric responses to geomagnetic storms.