Production of the low‐latitude night E layer

A recent study of data from Arecibo concluded that the night E layer must consist primarily of metallic ions produced by meteors. Full model calculations show that this is not necessary. Known EUV sources (from starlight, scattered sunlight, and F region recombination) will produce an E region that agrees well with Arecibo results throughout the night. Direct rocket observations confirm that metallic ions are insignificant in the E region at all times. Model and data also agree on the absence of any appreciable changes with season or solar activity in the night values of N m E . The large solar cycle change in the IRI‐95 model seems to come from an incorrect application of F region theory and should be deleted.