The companion paper by Zou et al. shows that the annual and semiannual variations in the peak F2-layer electron density (NmF2) at midlatitudes can be reproduced by a coupled thermosphere-ionosphere computational model (CTIP). without recourse to external influences such as the solar wind. or waves and tides originating in the lower atmosphere. https://allfixelectricales.shop/product-category/crimping-tool/