{'fraction_non_alphanumeric': 0.02168021680216802, 'fraction_numerical': 0.004516711833785004, 'mean_word_length': 5.595238095238095, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Comparison and Verification of the Different Schemes for the Ionization‐Recombination Cycle of the Ionospheric D‐Region

This study presents the results of a comparison and verification of three plasma‐chemical models of the lower ionosphere, which describe the dynamics of 4, 5, and 8 charged components under calm conditions and during X‐ray flares of different classes. As a result of verification of the constructed schemes for the ionization‐recombination cycle using data on the propagation of very low frequency signals during 12 X‐ray flares, the best agreement with experimental measurements was obtained with the eight‐component model of the ionospheric D‐region. On two of the four paths, this model successfully simulated the qualitative and quantitative response of the amplitude‐phase characteristics to solar flares in the C, M, and X classes. In contrast to the eight‐component model, four‐ and five‐component models are of limited accuracy which could not be noticeably increased by correcting the ionization rate calculation or the input values of the neutral parameters of the atmosphere.