First simulations of day-to-day variability of mid-latitude sporadic E layer structures

Abstract:

The first simulations of day-to-day variability of the mid-latitude sporadic E (Es) layers have been performed by a new three-dimensional local ionospheric model combined with neutral winds from GAIA (Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy) model. Es layers are thin layers of metallic ions appearing in the ionospheric E region. Although it is widely accepted that vertical zonal-wind shears of the atmospheric diurnal/semi-diurnal tides play a key role to the formation of the layers, no simulations to date have reproduced the Es layers observed on a certain day. This is due to the lack of the combination of realistic information on atmospheric tides in the lower ionosphere and a three-dimensional numerical ionospheric model that can simulate the precise transport of metallic ions.

In this study, we have developed a numerical local ionospheric model for the Es layers coupled with the neutral winds from GAIA model. The fundamental structures and the day-to-day variations of the Es layers observed by a Ca+ lidar are successfully reproduced in the simulations.