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

Abstract

We present the first simulations that successfully reproduce the day-to-day variability of the mid-latitude sporadic E (Es) layers. Es layers appearing in the lower ionosphere have been extensively investigated to monitor and forecast their effects on long-distance communication by radio waves. Although it is widely accepted that the atmospheric tides are important in generating the Es 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 the atmospheric tides in the lower ionosphere and a three-dimensional numerical ionospheric model that can simulate the precise transport of metallic ions. We developed a numerical ionospheric model coupled with the neutral winds from the GAIA (Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy). The fundamental structures and the day-to-day variations of the Es layers observed by a Ca + lidar are well-reproduced in the simulations. [Figure not available: see fulltext.]