Analysis of ionospheric response to solar flares at Kunming site

We presented in this paper the ionosphere variation characteristics during solar flares with location, season and solar activity level at Kunming site (25.6°N, 103.8°E), using the data measured by MF radar and ionosonde. Results showed: (1) the maximum amplitudes both D region and f
min
during solar flares appeared near at noon; there was no the strict corresponding relationship during solar flares between F layer critical frequency (foF2) and location time. (2) seasonal variation of increasing amplitude of electron density in D layer during solar flares reached the maximum in summer; that of f
min
was maximal in autumn, second in spring; that of foF2 reached the maximum in winter, second in autumn and least in spring. (3) the variation of ionosphere showed the positive correlation with the level of solar flare. (4) the ionosphere of D region had different characteristics with F layer ionosphere during solar flare on November 4, 2008.