F2 region response to geomagnetic disturbances across low latitude ionosphere
Abstract
The morphology of ionospheric storm has been investigated across equatorial and low latitude of Indian region. The deviation in F2 region parameters at equatorial stations Thiruvananthapuram (8.5°N, 76.8°E) and Delhi (28.6°N, 77.2°E) have been studied during five geomagnetic storm periods. The southward polarity reversal of the z component of the interplanetary magnetic field, Bz, is found to be highly correlated with the storm sudden commencement (SSC). Both positive and negative phases have been noticed during the study and it is observed that in spite of local time variation in Dst, the corresponding deviation in F layer parameter vary with the intensity of the storm as well as latitude of the observing stations. The positive storm phase over equatorial stations are found to be more frequent while the drop in ionization in most of the cases have been noticed at low latitude station of varying amplitude of deviations from the mean quiet day value. Due to disturbed electric field the simultaneous height rises have been noticed at these stations, with higher amplitude at CityDelhi in between 0000 to 0600 EMT. Positive deviation in foF2 is also observed across low latitude station during the storm which is attributed to daytime eastward electric field penetrating promptly from high to low latitudes. It may also be concluded that the reaction as seen at different ionospheric stations may be quiet different during the same storm depending on the station coordinates, local time of the magnetic disturbance beginning.
- Publication:
-
39th COSPAR Scientific Assembly
- Pub Date:
- July 2012
- Bibcode:
- 2012cosp...39.2032U