Effects of sporadic E-layer characteristics on spread-F generation in the nighttime ionosphere near a northern equatorial anomaly crest during solar minimum

摘要: Abstract This study is to know how the characteristics of sporadic E-layer (E s -layer) affect generation spread-F in nighttime ionosphere near crest equatorial ionization anomaly during solar minimum. The data E -layer parameters and are obtained from Chungli ionograms 1996. include foE (critical frequency -layer), fbE (blanketing Δ f (≡foE −fbE ). Results show that variations medians (Δ medians) different (similar to) occurrence probabilities spread-F. Because total number events greater than events, comparison between might have a shortfall. Further, we categorize into each interval parameters. For versus , an increasing trend found post-midnight all three seasons. also exists pre-midnight J-months seasons, for . These demonstrate increases with and/or Moreover, trends indicate polarization electric fields generated assist produce spread-F, through electrodynamical coupling F-region. Regarding significant only appears E-months. implies not be major factor formation.