Difference in the Sporadic E Layer Occurrence Ratio Between the Southern and Northern Low Magnetic Latitude Regions as Observed by COSMIC Radio Occultation Data

In this study, the difference in the sporadic E layer occurrence ratio between two low‐magnetic‐latitude (±5° to ±15°) regions is analyzed by using COSMIC scintillation observations covering the period from 2007.001 to 2017.365. Obvious longitudinal, seasonal, and LT dependencies of this phenomenon are found. Most features of the differences between two hemispheres could be explained by the difference in zonal vertical wind shear between the two hemispheres induced by the difference between the magnetic and geographic latitudes of the studied regions. This result also indicates that the wind shear mechanism still dominates sporadic E layer formation in low‐magnetic‐latitude regions. Key Points The difference in the sporadic E layer occurrence ratio between two low‐magnetic‐latitude regions is analyzed The difference in the sporadic E layer occurrence ratio between two hemispheres shows obvious longitudinal, seasonal, and LT dependencies The longitudinal, seasonal, and LT dependencies of this difference could be partly explained by the difference in vertical zonal wind shear