East Siberian Center for the Earth's Ionosphere Research (SDC ESCEIR)

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Incoherent scatter ionosphere diagnostics subdivision

Modelling, post processing and analysis of geophysical data

The ionosphere plasma parameters measured by the IS method are: the electron density N_e, the electron T_e and ion T_i temperatures, the ion composition, the drift velocity V_d, the basic parameters for determining the ionospheric structure and properties. Although their determination is based on the scattering process model, independent check-ups by rocket experiments have shown their correctness in experimental applications. Hence, we can consider data obtained, subject to confidence intervals and special reservations, to be sufficiently reliable experimental material.

Another group of ionospheric parameters -- such as the electron -- ion collision frequency, the ion -- neutral collision frequency, neutral temperature, heavy ion density and so on -- are secondary parameters. For determining them, we must use rather sophisticated semi-empirical lower-ionospheric models, which give relations of these parameters to measured basic parameters.

Thus, a typical ionospheric database can contain secondary parameters along with basic ones, for which we must specify the procedure of obtaining. The problem of developing reliable models and algorithms for determining of secondary parameters is a promising direction in investigating the relation between the atmosphere and the lower ionosphere.

Ionospheric data analysis, especially during strong disturbances, cannot be without some other kinds of diagnostic tools. These are, in the first place, magnetic observationae data, total electron content data from GPS systems, ionosonde data, ultraviolet satellite data, and so on. With this in mind, it is important to combine databases from different instruments into a single system to enable researchers to work most effectively. From this point of view, we must construct the database to give access to any kind of Internet geophysical information and make this database most effective.

One of the poorly known problems in ionospheric research is investigating longitudinal variations of ionospheric parameters. They are long-period variations associated with tidal waves, the passage thriuhh single large irregularities, possible effects of terrain, and so on. The lack of data has always been a challange in this case. But now we have an opportunity to initiate the investigation of this kind by using mid-latitude IS radar data from the Irkutsk, Kharkov, Millstone-Hill and Japan MU radars.