z-logo
open-access-imgOpen Access
Day‐to‐day variability of the E layer
Author(s) -
Moore Luke,
Mendillo Michael,
Martinis Carlos,
Bailey Scott
Publication year - 2006
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2005ja011448
Subject(s) - middle latitudes , ionosonde , latitude , atmospheric sciences , atmosphere (unit) , ionosphere , environmental science , climatology , geology , meteorology , electron density , geodesy , physics , geophysics , electron , quantum mechanics
Noontime day‐to‐day variability of ionosonde and incoherent scatter radar (ISR) measurements of the E layer are analyzed for two time periods: 9–27 March 1999 and 4 October–4 November 2002. E layer variability is found to be between 5 and 7% at midlatitudes for these periods. Polar latitudes demonstrate variability ranging from ∼7 to 50%, resulting primarily from a combination of photochemical and auroral processes. In order to understand the relative importance of the various sources that drive the variability in the E layer, a one‐dimensional time‐dependent photochemical model of the Earth's upper atmosphere is developed. The model is able to reproduce E layer electron density and variability for both time periods at a number of mid‐ and low‐latitude stations. It is shown that E layer variability is dominated by variations in the incident solar flux for mid‐ and low‐latitude stations, while auroral ionization processes are estimated to contribute roughly 30% of the total variability observed at polar stations. Changes in the solar declination over the time periods studied are responsible for a secondary source of E layer variability at midlatitudes and for a primary source at high latitudes. Day‐to‐day changes in neutral atmosphere species (including observed NO densities) contribute the least to overall E layer variations, except at low latitudes, where their contribution to variability is comparable to variability induced by changes in solar declination.

The content you want is available to Zendy users.

Already have an account? Click here to sign in.
Having issues? You can contact us here