Comparison of NeQuick, PIM, and TSM model results for the topside ionospheric plasma scale and transition heights Original Research Article

The topside ionospheric scale height (Ts) and the O+–H+ transition height (Th) are key ionospheric characteristics that are of special interest when studying and modelling the plasma composition and dynamics. Recently, a new Topside Sounder Model (TSM) has been developed which provides the Ts and Th quantities together with the ratio between them, Ts/Th. The database for this model has been built upon thousands of Ts and Th values deduced from electron density profiles retrieved from topside sounding measurements. For validation purposes, it would be interesting to compare calculations of the ionospheric scale/transition heights from TSM with corresponding calculations from two other well-known models – the NeQuick Model (NeQ) and the Parameterized Ionospheric Model (PIM). For the purpose, electron density profiles have been computed with both the NeQuick and PIM models over suitable grids of input parameters such as month, local time, geomagnetic latitude, solar activity, and in the altitude range between 200 and 2000 km. The topside ionospheric scale height and the O+–H+ transition height values have been extracted from each profile in the same manner as previously done for the TSM development database. Finally, the Ts and Th values deduced from the NeQuick and PIM profiles have been compared with the respective values provided by the TSM. Results of this comparison are analysed and suggestions are put forward for further improving the models in question. TSM applications are discussed as well.