On F2 response to geomagnetic storm

The interaction of solar wind with earth's magnetic field leads to a number of modifications of the F region global structure. Furthermore, the absorption of solar wind energy has the same phase all over the globe throughout the year. All these imply that there could be simultaneity in UT in global response of some F2 parameters to geomagnetic storms. Presently, F2 region global structure response to geomagnetic storm was studied using foF2 data obtained during the very intense geomagnetic storm (Ap>196) of 13-15 March 1989 from a global network of stations. The ionosonde stations located are at Ouagadougou (12.4), Manila (14.7ºN), Chung-Li (25.0ºN), Kokubunji (35.7ºN), Akita (39.7ºN), Boulder (40.0ºN), Rome (41.8ºN), Ottawa (45.4ºN), Wakkanai (45.4ºN), and Slough (54.5ºN) and Churchill (58.8ºN). The present result obtained using derived ratios R(foF2) show that all the stations showed some high degree of simultaneity in the depletion of foF2 between 0000 and 1200 UT on 14 March