Relationship between Various Types of Sporadic-E &. Magnetic Activity

189-195A study has been made or different types or sporadic-E and their relationships with magnetic activity. Evidence is given to suggest that the changes in the occurrence or low-type of Es may be related to changes In the magnetic field. Changes in the behaviour of cusp-types of Es are considered to be related to the interaction between quiet solar and disturbed polar current systems. It has also been found that the superposition of low and high type Es has a magnetic dependence similar to that of flat-type. The complete opaque layer of Es with no F-region echo can exist only under special circumstances