We report a new ionosphere phenomenon: Equatorial ionization anomaly (EIA) discontinuity (EIAD), based on OI 135.6 nm radiance observations from the Global Observations of Limb and Disk (GOLD), ground-based total electron content maps in-situ ion density data Constellation Observing System for Meteorology, Ionosphere, Climate-2. The EIAD occurs when EIA crest has local minimum, at fixed UT, wit...