Electromagnetic and acoustic-gravity wave coupling in Lithosphere (Earth)-Atmosphere-Ionosphere-Magnetosphere (LEAIM) system in «vertical» and «horizontal» directions and radio diagnostics

Ionospheric space weather (ISW) is formed when LEAIM system is impacted by powerful sources located above the ionosphere (from solar wind and magnetosphere during strong magnetic storms), within atmosphere-ionosphere (lightnings; instabilities in active nonlinear atmosphere-ionosphere), and below the ionosphere (in the lower atmosphere or within Earth, including hurricanes, earthquakes, and volcanoes). One of the key issues in understanding mechanisms of ISW formation is the study, modeling, and comparison with experiment of processes of interactions and propagation of wave disturbances in "vertical" and "horizontal" (latitude-longitude) directions in open dynamic active/dissipative LEAIM system, including the ionosphere. Synergistic approach required for such studies requires multiparameter ground-based and satellite methods for diagnosing ionospheric plasma structures (IPS), including Traveling Ionospheric Disturbances (TIDs). Radio diagnostics, including the use of GNSS data, LOFAR (Low-FRequency Radio Telescope Array), Ionosondes, VLF (Very Low Frequency/kHz) Radio Waves in the Earth-Ionospheric Waveguide, etc., constitutes an important part of radio diagnostic methods. In particular, methods and models for excitation of electromagnetic waves (EMW) and acoustic-gravity waves (AGW) by current and hydrodynamic/thermal sources are being developed and will be presented, including lightning sources EMWs in lower atmosphere and mesosphere associated with volcanoes; excitation of AGW and EMW by ground and lithospheric current sources associated with seismic processes; excitation by ionospheric current-thermal sources of AGW/IPS/TIDs (Travelling Ionospheric Disturbances), penetrating from upper to middle and low latitudes; these sources are located at high latitudes/auroral oval or middle latitudes, and they are associated with the penetration of magnetospheric currents into ionosphere during magnetic storms; solar terminator as a source of AGW/TIDs;  developing Perkins instability in the middle-latitude ionosphere in the presence of AGWs as a seeding factor and radio wave scattering on the excited nonlinear IPS; models of scattering of high-frequency EMW/LOFAR (MHz) radio waves on IPS. The following breakthrough experimental-theoretical results in the field of atmospheric electricity theory will be presented. (1) Hunga Tonga volcano eradication (HTVE) (January 2022) caused unprecedented lightning currents in lower atmosphere of order 5*10^-7 A/m², exceeding fine-weather current by 5 orders of magnitude; unprecedented influence of radon on conductivity, electric and magnetic fields in the lower atmosphere in region of Popocatepetl volcano was discovered; electric field can exceed the fine-weather field by 5 orders of magnitude, with coronal discharge between charged cloud and volcano cone. Therefore seismogenic  electromagnetic fields of ULF and ELF (Ultra- and Extremally Low frequencies, respectively) and VLF ranges penetrate into ionosphere and are capable to form ISW; (2) new model of planetary-scale MHD/AGW vortex structures gives spatial periods and velocities which are in agreement with ionospheric satellite observations; (3) combined complex-geometrical optics-beam method for radio weave scattering on the IPS/TIDs is developed; birefringence and dependence of radio wave frequency on the TID velocity is included; astrophysical sources are used as “projectors”  irradiating the IPS under investigation, while LOFAR is used as a detector of the scattering waves; (4) new model of AGW/TIDs excitation by solar terminator provides characteristics parameters (periods, velocities) and tiny peculiarities of structures corresponding to GNSS and LOFAR observations.