We considered the phenomenon of reflection of light radiation from crystalline particles preferentially oriented in the atmosphere, as well as the physical patterns and possible conditions favoring this reflection. Experimental observations were used to analyze the recorded light spots, occurring due to reflection of radiation from layers of these particles. We describe a case of recording specular layers using a panoramic optical station (AllSky system).

Представляются экспериментальные результаты исследования особенностей формирования и распространения интенсивных световых каналов в условиях структурирования начального профиля пучка мощного фемтосекундного лазерного излучения в виде отдельных субапертур. Такое особым образом структурированное излучение получено путем амплитудной модуляции лазерного пучка с использованием масок. Применение амплитудных масок позволяет получить заданное число высокоинтенсивных световых каналов, и осуществить их управляемое распространение в конкретном нелинейном режиме, преимущественно на небольших (десятки метров) расстояниях в атмосфере.

The results of analysis of aerosol in aqueous NaCl solution by the femtosecond-pulse laser-induced breakdown spectroscopy (FS-LIBS) method are considered. Estimates are presented for the impurity (Na) concentration by the analytical pair method using the additive method. We chose, as an internal standard line, the radiation of the atomic nitrogen ion N+ at a wavelength of 500.515 nm, formed from atmospheric nitrogen molecules in the filamentation domain. A possibility of estimating the concentration of a chemical compound (NaCl) from emission of its constituent part (Na) in aqueous aerosol by the FS-LIBS method is interesting for developing the femtosecond lidar sounding techniques.

The results of synchronous remote (lidar) and direct (balloon) measurements of tropospheric and stratospheric aerosol parameters carried out in Tomsk on January 27–30, 2022 are presented. The objective of the experiment was to work off coupled lidar-balloon observations and to validate aerosol backscatter profiles in the upper troposphere and the stratosphere for developing an all-weather system for lidar-balloon monitoring of spatiotemporal and microphysical aerosol characteristics. A good consistency of the retrieved profiles of the backscatter ratio R(H) was demonstrated for the close wavelengths (528 and 532 nm for the aerosol backscatter sonde and the lidar, respectively). The possibility of expanding two-wave (353 and 532 nm) lidar observations with an additional wavelength set (470, 850, 940 nm) of the optical balloon aerosol sonde was shown for retrieving the microphysical aerosol parameters during coupled lidar-balloon experiments.

The results of experimental studies of the features of formation and path propagation of high-intensity light channels under conditions of distortions of the initial profile of a high-power femtosecond laser radiation beam are presented. The distortions are introduced by amplitude modulation of the laser beam using masks. The use of amplitude masks allows generation of a preset number of high-intensity light channels and their controllable filamentation mainly at short (tens of meters) distances of radiation propagation in air.

According to the results of studying the interaction of high-power femtosecond pulsed radiation from a titanium–sapphire laser with the aerosol particles of an aqueous solution of NaCl, we estimate the directional pattern of Na emission from the filamentation region. It has been found that this directional pattern is characterized by minima in angular directions of 0° and 180° and a maximum in an angular direction between 20° and 160°. Based on the results of recording of supercontinuum radiation formed in the air and scattered by aerosol particles, the features of the aerosol particle size distribution have been determined. Gradient optimization methods using graphic processors were employed to speed up calculations. The neural network was used as an optimization method.

We present the results of joint observations of ozone and temperature in the middle atmosphere above Tomsk in December–January 2012–2013 and in December–February 2014–2015 during stratospheric warmings. The results of simultaneous microwave observations of ozone in Peterhof (60° N, 30° E) and Tomsk (56° N, 85° E) in the winter of 2013–2014 are also given. Ground-based microwave radiometry and laser diagnostics were used in the observations. Microwave radiometry and lidar technology allow us to study ozone and temperature variations during large-scale wave disturbances in the middle atmosphere such as stratospheric warming.

Рассмотрение результатов взаимодействия электромагнитного излучения с несферическими атмосферными частицами, обладающими анизотропными свойствами, представляет как научный, так и практический интерес. Особо следует выделить взаимодействие направленного оптического излучения с пространственно ориентированными атмосферными кристаллами льда. Неучет зеркального отражения оптического излучения от ансамбля пространственно ориентированных атмосферных частиц несферической формы может исказить модельные представления, существенно затруднить интерпретацию получаемых результатов и привести к неверному трактованию некоторых наблюдаемых в атмосфере явлений. В работе рассмотрены некоторые результаты наблюдений явления зеркального отражения от локализованных в атмосфере горизонтально-ориентированных плоских кристаллических части.

В Институте оптики атмосферы СО РАН, в интересах оперативного мониторинга воздушного пространства на протяжении многих лет ведется разработка методов и средств мониторинга и контроля атмосферного пространства, преимущественно в оптическом диапазоне. Среди этих методов наибольшее внимание было уделено развитию лидарных методов. Одним из факторов, влияющих как на возможность проведения измерений, так и на их результаты, является текущее качество атмосферы. В работе предлагается методика определения одного из параметров астроклимата – прозрачности атмосферы, на основе анализа allsky изображений, получаемых с помощью панорамно-оптической станции.

In laboratory conditions, the fluorescence spectra of rhodamine 6G were obtained in the domain of post-filamentation channels upon interaction with femtosecond laser radiation. A fluorescence signal was received from a distance of 7.5 m from the aerosol and the droplet according to the lidar sensing scheme.

The results of experimental and theoretical studies of the evolution of the small-scale transverse structure of high-power femtosecond laser radiation propagating in air in the multiple filamentation mode are presented. It has been found that the presence of intensity inhomogeneities in the initial transverse profile of the laser beam leads to the formation of spatially isolated light channels due to the Kerr self-focusing effect. When the power in these channels exceeds a certain threshold value (the critical power), radiation filamentation occurs in them. The parameters of these light channels are theoretically estimated on the basis of the diffraction-ray model of single filamentation. It is shown that for a laser beam with a centimeter radius and subterawatt power, the initial radius of intensity inhomogeneities in the transverse profile has a characteristic value of several millimeters.

The article presents an overview of the panoramic optical station "TomSky" developed at the Institute of Atmospheric Optics SB RAS, designed for day and night multiparametric observation of the optical state of the sky. In the first part, the prerequisites for creating a ground-based atmospheric monitoring station and some technical features of its implementation are considered. This study was supported by the Ministry of Science and Higher Education of the Russian Federation.

The article presents an overview of the panoramic optical station "TomSky" developed at the IOA SB RAS, designed for day and night multiparametric observation of the optical state of the sky. In the second part, methods and algorithms for processing data obtained from the monitoring station are considered. This study was supported by the Ministry of Science and Higher Education of the Russian Federation.

Results of the complex experimental study of the spectral and temporal characteristics of the emission glow of control samples of several solid-state substances (imitation of topographic targets in the atmosphere) and of solid aerosols (imitation of air pollutants) under the action of femtosecond pulses of a Ti:Sa laser (at a carrier wavelength of 800 nm) and nonlinear optical effects are presented.

The report presents the results of estimating the angular distribution of emission of impurity from the breakdown region of aerosol by femtosecond pulses in the range from 0о to 180о and the intensity of the emission line depending on the concentration of the impurity for the problem of remote sensing by the femtosecond laser-induced breakdown method.

Analysis of the data on the annual variability of the vertical-temporal structure of the background aerosol and its integral filling in the stratosphere, obtained at the lidar complex of the high-altitude atmospheric sounding station of the IAO SB RAS in 2020 is studied in this paper in comparison with previous years. Based on the monitoring results, as in previous years, a stable tendency of accumulation of stratospheric aerosol in the cold period of the year was revealed with a maximum content in January and a decrease in the warm period until its practical absence in June-July. In the upper stratosphere (30-50 km), the background aerosol is absent throughout the year.

A brief analysis of works devoted to the detection of greenhouse gas sources using lidars placed on space platforms is given, and the differential optical depth along the sensing path from a spacecraft is estimated for various models of carbon dioxide sources during IPDA sounding at wavelengths in the region of 1.572 μm.

The results are presented of experiments on controlling the characteristics of the multiple filamentation domain of femtosecond laser pulses along atmospheric paths via variations in the initial spatial focusing, beam radius, and pulse energy, as well as the optical field structure at the initial beam aperture.