in natural environments and their diagnostics
The experience gained by the Nizhny Novgorod (Gorky) Radiophysical School in studying instabilities, waves, and structures, as well as in developing remote sensing methods of environmental diagnostics, has led to the formation of the IAP RAS interdisciplinary scientific field dealing with the study of geophysical phenomena in natural environments, such as ocean, atmosphere, ionosphere, magnetosphere, and solid earth. The basis for this integration was radiophysical methods of environmental research. Radiophysics, understood in a wide sense as a general science on oscillations and waves of different physical nature and in various ranges, allows a unified address to a wide spectrum of specific tasks related to environmental research. This common ground in the formulation of problems and approaches to their solutions proves to be particularly effective in developing methods and facilities of remote diagnostics of natural media and objects, i.e., in the field, the relevance of which has notably increased. That is why many modern radiophysical research lines actively developed today at the IAP RAS are attributed to the problems of remote diagnostics and tomography of geophysical plasma, hydrosphere and atmosphere of the Earth, and terrestrial rocks.
One of the most topical problems of modern geophysics is improving methods of monitoring, modeling, and forecasting hazardous (including disastrous) fast geophysical phenomena. To optimize technologies for monitoring and forecasting of disasters, it is necessary to study the mechanisms and spatio-temporal characteristics of nonstationary geophysical phenomena using present-day achievements of radio physics and nonlinear physics. The studies carried out at the IAP RAS encompass various geospheric shells, such as the ocean (hurricanes, tsunamis, and rogue waves), the lower (energetic rainstorms, thunderstorms, and hail) and the middle atmosphere (the ozone hole, sprites, and jets), ionosphere and magnetosphere (precipitation of fast particles), and the lithosphere (landslides, erosion, and karst). Many nonstationary geophysical phenomena (especially hurricanes) affect several geospheric shells, thus their adequate comprehension is based on an integrated monitoring and physico-mathematical modeling of the interaction of geospheres.
A unique multifunctional complex of scientific and technical equipment has been developed at the IAP RAS, including two largest Russian facilities for modeling phenomena in the ocean (Large thermostratified tank) and in the ionized Earth shells (plasma setup "Krot"), a complex apparatus for microwave sounding of the Earth's surface and the atmosphere, a complex for reception and recording of electromagnetic fields, an onboard equipment for remote diagnostics of the sea surface, and a receiving-emitting equipment complex of seismoacoustic diagnostics. This allows a unified solution of specific scientific and technical problems of natural environment diagnostics, including those of fast geophysical phenomena.
An important direction in the development and wide application of geo-informational and geo-engineering (related to the effect on natural processes) technologies is to ensure environmental safety: monitoring and early detection of various factors of environmental pollution and system changes of geophysical environment resulting from human impact. The technologies developed at the IAP RAS are widely used on behalf of a number of ministries and departments, including the Ministry of Natural Resources, RF Ministry of Emergencies, Ministry of Agriculture, and local authorities. Cooperation with Agencies of Federal Service of Hydrometeorology and Environmental Monitoring, primarily with the Department of Hydrometeorology of the Volga Federal District, is successfully developed in recent years. In the near future, it is planned to actively participate in the development of a monitoring system for climate changes across the country.
The problems of remote diagnostics are, in fact, ill-posed inverse problems of reconstructing the properties of objects from their intrinsic radiation (passive diagnostics) or from their "reaction" to external forcing (active diagnostics). To diagnose the environment, wave signals of different physical nature are used. The scientific research lines focused on the study of physical phenomena in the ocean, the atmosphere, and their diagnostics are adjacent to other two researches long and intensely developed at the Institute, i.e., millimeter and submillimeter radio astronomy and molecular spectroscopy.