GRAVITY-WAVE GENERATION AND PROPAGATION DURING GEOMAGNETIC STORMS OVER KIRUNA (67.8-DEGREES-N, 20.4-DEGREES-E)

Atmospheric gravity waves, detected over Kiruna (67.8 degrees N, 20.4 degrees E) during geomagnetic storms, are presented and analysed. The data include direct measurements of the OI 630.0 nm emission line inte nsity, the x-component of the local geomagnetic field and thermospheri c (meridional and zonal) wind velocities derived from the OI 630.0 nm Doppler shift observed with an imaging Fabry-Perot interferometer (IFP I). A low pass band filter technique was used to determine short-perio d variations in the thermospheric meridional wind velocities observed during geomagnetic storms. These short-period variations in the meridi onal wind velocities, which are identified as due to gravity waves, ar e compared to the corresponding variations observed in the OI 630.0 nm emission line intensity, x-component of the local geomagnetic field a nd the location of the auroral electrojet. A cross-correlation analysi s was used to calculate the propagation velocities of the observed gra vity waves.