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A regression approach is presented for the problem of restoring the sea surface temperature (SST) from radiometric measurements of a microwave radiometer–spectrometer (MIRS) in the Convergence Space Experiment at frequencies of 10.65, 18.7, and 36.5 GHz. A feature of the proposed regression approach is the use of a limited set of frequencies (10.65, 18.7, and 36.5 GHz) with vertical and horizontal polarization at each one. The selection of a regression relationship with quadratic terms is validated. The problem of restoring the SST based on true space-based measurements using the WindSat instrument is modeled and compared to reanalysis. Estimates of the accuracy of determining the SST show that an error of around 1 K can be achieved, which is confirmed by theoretical calculations of measuring errors.

The original MicRAWinD (Microwave Radiometric Algorithm for Wind Direction retrieval) algorithm planned for use in reconstructing the near-surface wind direction in the Convergence space experiment (SE) is presented. The possibility of determining the wind direction based on radiometric measurements in two swaths of the radiometer stems from the anisotropy of surface radiation, which is manifested most clearly in the third Stokes parameter. Combining the results of measurements at different frequencies with their reliability factored in, one can improve the accuracy of reconstructing the wind direction. A new algorithm for enhancing the reliability of measurements which takes the real errors in measuring brightness temperatures into account is proposed. The algorithm has been tested with real data provided by the WindSat radiometric system. The results are compared with the Remote Sensing Systems (RSS) reconstruction data. A surface region with different geophysical parameters (sea surface temperature, vapor content, wind speed and direction, and cloud water content) is chosen for this comparison. The reconstruction algorithm involves solving the direct problem of calculating the radio brightness temperatures at linear ±45° polarizations with subsequent calculations of the third Stokes parameter for 37, 18.7, and 10.7 GHz. The initial meteorological parameters for the direct problem are products provided by RSS. The sensitivity of radiometric instruments is taken into account in the simulation process. The solution of the inverse problem and the comparison results demonstrate that this algorithm retrieves the wind direction with fine qualitative agreement both from the results of radiometric observations at a single frequency and from multifrequency data.

The purpose of this research is to present a detailed description of the proposed Convergence space mission on the Russian segment of the International Space Station for the wider scientific community. The key features of the mission are (1) the necessity of creating a new type of multifrequency radio-thermal airborne complexes with a specialized set of operating frequencies and with the formation of algorithms and software for the three-dimensional recovery of the water-vapor field in the lower troposphere and for estimating the horizontal advection and convective latent heat fluxes at different altitudes and with different forms of boundaries of the investigated regions. (2) An important part of the mission is the global monitoring of optical transient activity, including lightning in cloud tropospheric systems and electric discharges in the upper atmosphere, which are accompanied by a variety of short-term optical glows, commonly called transient luminous events. A significant contribution to the elucidation of the physics and the development of models of high-altitude electric discharges is the synchronous operation of the lightning detector and gamma detector to search for and study gamma-ray bursts of terrestrial origin, including those in previously unexplored latitudes, up to ±51°. It seems that the proposed instrumental configuration and integrity of the mission, which includes the synchronous operation of devices of different ranges of electromagnetic radiation (both the microwave range and optical and gamma range) will contribute significantly to the elucidation of the physics of processes of interaction of catastrophic atmospheric phenomena of the hydrodynamic type, i.e., tropical cyclones, with the electrical activity of tropospheric cloud systems (the field of lightning discharges) and activity of high-altitude electric discharges, which, in turn, can serve as a serious experimental basis for the formation of physical ideas about the genesis of gamma-ray outbreaks of terrestrial origin.

This paper presents an analysis of the experimental measurements of the azimuthal anisotropy of the microwave emissions of a rough water surface. The experimental data were obtained using microwave radiometers with operating frequencies of ~37 GHz (a wavelength of ~8 mm) on the oceanographic platform of the Black Sea Hydrophysical Experimental Facility of the Russian Academy of Sciences in the period from 2005 to 2016. This paper describes the azimuthal anisotropy effect, experimental studies, measurement methods, and data processing. A qualitative comparison of the measurement results with the model calculations and other experimental studies of anisotropy was performed. It was shown that there is a strong sensitivity of the variation in the radio emissions of a rough water surface, both to the wind speed and to its direction at different incidence observation angles.

This paper presents the functional dependence of the microwave emission of a rough water surface at a frequency of 37.5 GHz (wavelength of ~8 mm). The MiROSE model (Microwave Rough Ocean Surface Emission model) is based on the experimental studies of the own thermal radio emission of the water surface, which were carried out in 2005 and 2007 on the oceanographic platform of the Black Sea Hydrophysical Experimental Facility of the Russian Academy of Sciences. This paper demonstrates the steps of the simulation for selecting the optimal functions to describe the incident angle, wind, and temperature dependences of the increment of the own water surface emission. The following parameters can be calculated on the basis of the proposed model: the increment of the brightness temperature, radio-brightness contrast, and radio-brightness temperature for horizontal and vertical polarizations of the received emission. The model is applicable to water temperatures ranging from 12.5 to 25°C, wind speeds of 3–13 m/s, and incident angles of 30°–80° measured from the nadir.

A correlation analysis of the model calculations and experimental measurements of wind-speed sensitivity of a rough sea-surface microwave emission at a frequency of 37.5 GHz are presented. The field data used in the research were collected over 3 years in the summer and autumn periods at the oceanographic platform of the Marine Hydrophysical Institute, Russian Academy of Sciences (RAS). A hypothesis about a significant correlation between the model calculations and experimentally measured sea-surface emission ability caused by wind forcing was formulated and tested to reveal this correlation. An evaluation of the discrepancy between the model and experimental data has been performed by an analysis of residuals. Our studies have shown that among the selected models not a single one adequately describes the experimental data.

The results of in situ measurements of the characteristics of intrinsic microwave radiation from the sea surface are presented. The studies were carried out on the oceanographic platform of the Experimental Department of Marine Hydrophysical Institute during the summer–fall periods for 3 years, which made it possible to accumulate a significant amount of information on the change in the radiation intensity of under different meteorological conditions. Attention is primarily focused on the construction of wind-radiation dependences and their steepness analysis based on the measurement data obtained by a radiometer-polarimeter with a central frequency of received radiation equal to 37.7 GHz. The results are compared with the previous experimental studies and the model estimates of this effect.

The results of comprehensive studies of transformation of hydrocarbons in light catalytic gasoil (LCG) by ozone in different ozonation conditions are reported. It was found that low-temperature oxidative cracking and oxidative polycondensation reactions take place as a result of electrophilic 1,3-addition of ozone to the components of the LCG. The flash point of the samples decreased, and the concentration of adsorption resins increased. Olefins have the highest activity in interaction with ozone. The optimum conditions of ozonation of LCG were selected.

Ozonation of diesel cuts with different sulfur contents was investigated. Intensive gum formation and formation of insoluble products take place during the process. At temperatures below 20°C, the intensity of gum formation decreases significantly. The existent gum content increases with an increase in the ozonation time. At 0°C and higher, ozonolysis is accompanied by intensive foaming.