Premium
Concluding remarks, session 2: Structure, ionization sources
Author(s) -
Davies Kenneth
Publication year - 1975
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/rs010i003p00411
Subject(s) - ionosphere , ionization , midnight , sunset , physics , ion , plasma , electron , daytime , atomic physics , session (web analytics) , atmospheric sciences , astronomy , nuclear physics , computer science , quantum mechanics , world wide web
There are three major topics which arose in Session 2 on which I would like to comment, namely, maintenance of the night ionosphere, particle ionization, and modelling. 1. THE NIGHT IONOSPHERE The maximum densities of the E and intermediate layers decay at night to values of the order of 3×10 3 cm −3 . Taking a low value of α ≈ 10 −8 cm 3 sec −1 , then N e = 4.96×10 4 cm −3 at sunset and the electrons would completely disappear within an hour after production ceases. Not only does the E ‐layer ionization persist but evidence (Geller et al .) indicates that after midnight, the ion production in the upper E region increases markedly. Incidentally, ionospheric total content data show that the content of the F region can also increase around midnight. Hence, a source of plasma is required.