ИСТИНА

Central industrial region of Russia, as one of the most populated and industrialized region of the whole Rus-sian Federation, is characterized by complicated ecological situation. In the Moscow city urban agglomeration a huge human population and industrial power is concentrated on a relatively small area. Moscow with its suburbs, therefore, is a notable source of anthropogenic perturbations of the natural environment. Due to its high con-sumption of heat and electrical energy, motor fuel, and relatively low albedo of urban landscape in visible solar spectrum, the city in fact is a strong and compact source of heat, deposited in the surrounding atmosphere. In addition, there are strong emissions of water vapor, carbon dioxide, soot, dust, aerosols etc., influencing local heat and radiation balance in the atmosphere. All the mentioned impacts cause strong perturbations of natural fields of the atmospheric parameters, e.g. temperature, pressure and relative humidity. As a consequence, there can be generated acoustical gravity waves, propagating upward and reaching ionospheric heights. These pertur-bations largely determine regional atmospheric dynamics, local climate and air mass transport in the city and the region. The complexity of the problem increases additionally due to huge variety of the sources of the acoustical gravity waves, like thermal and orographic inhomogeneities of the underlying surface. Thus, influence of the urban environment on the air mass transport has been repeatedly proved in the experiments. Studies show that the acoustical gravity waves, excited by the wave source at the source of the Earth, can indeed reach the iono-sphere, provided their destruction due to the non-linear effects and further extinction take place at the heights above the main ionospheric maximum of the F2 plasma layer [1] During the propagation in the atmosphere, the most stable are the waves with periods close to the buoyancy (Brunt-Vaisala) frequency of the free vertical oscillations of stratified atmosphere. Typical frequencies of the acoustical gravity waves are lower than buoyancy frequencies at the ionospheric heights, while the velocities do not exceed the sound speed at there heights, which are from hundreds of meters up to 2 kilometers per second. [2 ]. For this reason, techniques of regional monitoring of the atmosphere, including both precision local in situ measurements and remote sensing of various atmospheric parameters, providing average estimates in areas, not covered by contact measurements, are of especial importance. Complexity of this problem is caused primarily by lack of various observation data, both satellite and meteorological. Due to that, development of combined tech-niques, capable for assimilation and integration of heterogeneous data, is now extremely important. The objective of the present study is development of complex approach to analysis of multi-instrumental data of regional atmospheric monitoring, including in situ airborne measurements together with remote sensing data, including radio occultation and interferometric experiments with radio navigational satellite systems. Radio occultation technique for regional monitoring of the atmosphere: Radio occultation technique, as a powerful and promising remote sensing technique, has been widely applied for satellite observations of the planetary atmospheres and ionospheres during more than 40 years. In the last 15 years this technique is actively used for the satellite monitoring of the terrestrial environment. Since 2001, formation of an international global system of radio occultation monitoring of terrestrial atmosphere has been started. The system includes several low Earth orbiters, capable of receiving of radio signals of 24 navigational GPS satellites, thus performing more than three thousands radio occultation events every day. The system uses space-borne receivers GRACE, COSMIC and other types, orbiting nearly circular orbits with inclination of 75-85 degrees and height about 500 - 700 kilometers. Development of these techniques significantly improved the quality of assimilated data, partly removing the limitations of traditionally applied techniques and mitigating the impact of the noise on the process and result of the experimental research, to obtain more comprehensive information about the structure of envi-ronment being sounded. In the practice of radio occultation sounding, starting from the pioneering works [3] until the end of the twen-tieth century, theoretical basis of the method was the geometrical optics approximation. One of the most impor-tant disadvantages of the method is its poor horizontal resolution, largely caused by small curvature of the at-mosphere and long propagation distance of the sounding signal in it. Vertical resolution of the technique is also limited, in particular, by the diffraction scale. Detection and assessment of the parameters of the atmospheric structures, not exceeding and comparable to the Fresnel zone size, requires application of the proper methods, accounting for the wave effects (radio holography, diffractional tomography) and a priori information usage. For the validation of the geometrical optics (GO) approximation in the particular wave propagation situation, and de-tection of violation of ray approximation, we apply the approach based on the adiabatic invariant [4]. The ap-proach allows reveal the connections between the observed wave field quantities, functional dependence be-tween which otherwise cannot be established. Revealing the features of re-distribution of the radiation energy, connected with the variations of the Doppler wave frequency shift in the monochromatic RO experiment caused by the refraction in the spherically symmetrical gaseous envelope of the planet, allows detection of thin atmos-pheric layers, typically masked by the measurements noise and atmospheric turbulence. Conditions of conserva-tion of the adiabatic invariant, which in fact is an indicator of validity of the geometrical optics approximation, were investigated by the authors in the series of direct simulations of the wave field in the inhomogeneous at-mosphere with the numerical solution of the parabolic diffraction equation. Computer simulations of the wave fields in large domains with sizes, greatly exceeding the wavelength, is a separate challenging computing task, consuming much time and computational resources. Combined data processing approach: We not only apply new methods of the adiabatic invariant for the com-plex vertical profile analysis, but we assimilate additional information, obtained from radio interference measure-ments of the navigational satellite signals on the ground based regional GPS receivers network. Essentials of the GPS interferometry technique for separation of ionospheric wave perturbations, applied in this work, based on simultaneous phase processing at two GPS operational frequencies L1 and L2 and further filtration of the signals for selection of waves with typical periods exceeding three minutes. [5] For detection of wave structures, the groups of three stations each, providing minimal data set for the proc-essing, were specially organized. Ionospheric perturbations, initially retrieved from correlation measurements, are further classified by cluster analysis. The structure is supposed to be reliably detected if the correlation meas-urements of the given number of groups retrieve similar parameters. In the study we pay a special attention to specific atmospheric situations, taking place during last years, such as anomalously hot summer in 2010, accompanied by the blocking cyclone, causing dramatic consequences in Canada, Europe and Russian Federation. In this study, radio interferometric data for Moscow, Russia and Fair-banks, Alaska, USA have been processed and analyzed. Ionospheric wave structure parameters, retrieved with this approach, were in turn analyzed together with the vertical profiles of atmopheric parameters measured in situ with radiosondes. Acknowledgements: The present study is supported by the Russian Fundamental Research Fund (project 15-45-03266). Authors thank the Moscow State University computational facility for granting access to the high performance parallel computing systems “Lomonosov” and “Tchebyusheff”. References 1. Gavrilov, N.M., Kshevetskii, S.P. Numerical modeling of the propagation of nonlinear acoustic-gravity waves in the middle and upper atmosphere (2014) Izvestiya - Atmospheric and Ocean Phys-ics, 50 (1), pp. 66-72. 2. Gossard, E. E. and Hooke, W. H. Waves in the Atmosphere, 456 pp., 1975. Elsevier. 3. Phinney, R.A. and Anderson, D.L. (1968). On the radio occultation method for studying planetary atmospheres. Journal of Geophysical Research 73: doi: 10.1029/JA073i005p01819. issn: 0148-0227. 4. Gavrik A.L., Ilyushin Ya.A. Structure of the multi-ray radio wave field in the Venusian ionosphere: numerical simulations with parabolic diffraction equation. Abstracts of the Fourth Moscow Solar System Symposium 4ms3-PS-44 5. Zakharov, V.I., Kunitsyn, V.E. Regional features of atmospheric manifestations of tropical cyclones according to ground-based GPS network data (2012) Geomagnetism and Aeronomy, 52 (4), pp. 533-545.