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The results of numerical and experimental studies on the control and management of optical elements of an electric-discharge KrF laser using the developed method based on DBSCAN are presented. Various methods for processing the data obtained from the position-sensitive detectors and a possibility of using the DBSCAN algorithm to increase the speed of the optical system alignment automation device are considered. The conditions for correcting controlled mirrors with an accuracy of their return of 60 ± 10 mrad are determined. The adjustment time does not exceed 5 min.

We present the results of model experiments on recording the spectral characteristics of the emission glow of residual amounts of a substance on a blade of an aircraft turbojet engine after the mechanical impact of a foreign object. The spectra were measured by laser-spark spectroscopy, which made it possible to distinguish the emission lines of this substance against the spectrum of the blade material. This non-destructive testing method makes it possible to quickly diagnose the blades at the site of the aircraft inspection before a flight and to draw conclusions about possible destruction of the fuselage and the danger of the damage.

The results of calculation of the absorption spectrum of phosphorus oxide (PO) corresponding to the transition A ²S⁺ ( v′ = 0) - X ²P ( v″ = 0) are presented. The calculation is performed taking into account the perturbation of the v′ = 0 level of the A ²S⁺ state by the v′ = 4 level of the b⁴S^- state. The efficiency of laser excitation of PO molecules is estimated as a function of the spectral parameters of the radiation. The time dependence of the efficiency of the excitation of PO fragments was calculated in the real atmosphere under two-pulse laser fragmentation of organophosphates for specified spectral line widths Δλ and center positions λ₀.

The integration of the parameters of the CDSD, NOSD, NDSD and ASD data banks developed at the Laboratory of Theoretical Spectroscopy, Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, into a single node of the Virtual Atomic and Molecular Data Center (VAMDC) is described. As part of this work, software was written that implements XML-formatted data exchange with the VAMDC portal and integrates the data banks into the distributed infrastructure.

Modern changes in the Earth's climate due to increase in greenhouse gas concentrations, primarily carbon dioxide, stimulate the monitoring of its content by various methods. In the study, we compared CO₂ content in the lower stratosphere (12-18 km altitude layer) from ground-based Bruker 125HR spectrometer and satellite ACE instrument measurements in 2009-2019. The analysis of two measurement types shows a good agreement between them. Ground-based CO₂ measurements, on average, exceed satellite data by 2.8 ppm (less than 1%), standard deviations of the differences are ~ 5.0 ppm. The correlation coefficient between two datasets is 0.77. Ground-based (Bruker 125HR) and satellite (ACE) CO₂ measurements show weak seasonal variations, opposite to the variations in tropospheric CO₂. The CO₂ content in the lower stratosphere is maximal in summer and minimal in winter.

It is shown that the approximate Vorobyov formula linking the lidar returns with the intensity of optical turbulence, for the case of a statistically homogeneous medium with an accuracy up to a constant coefficient, satisfactorily agrees with the sounding data. The procedure for determining the coefficient in the Vorobyov formula for a specific lidar aperture size is recommended. The construction of a nomogram for the operational determination of the intensity of homogeneous turbulence from lidar readings is proposed. The discrepancy between the experimental results and the theory when sounding inhomogeneous turbulence is established. It is shown that the main contribution to the formation of the turbulent component of a lidar return due to the BSE effect is made by the section of the path in front of the scattering volume. It is proposed to use an approximate formula to restore the structure parameter of the optical turbulence C_n², in which normalized C_n² is directly proportional to the return and inversely proportional to the integral determining the dispersion of intensity fluctuations.

In our nuclear age, fears are expressed about the fate of the Earth's ozone layer, and it is believed that both large-scale and local nuclear conflicts can destroy the ozone layer for years. On September 22, 1979, an unidentified state secretly performed a nuclear test in a desolate region of the World Ocean. This event is commonly referred to as the Vela Incident. In this work, we used ozone data obtained by the NASA satellite Nimbus-7 17 minutes after the explosion. It is shown that the shock wave left a mark on the ozone layer. No decrease in the amount of ozone is noticed. The coordinates of the explosion site are determined from the mark.

The article provides a brief overview of the collection of GrafOnto water absorption plots in the 1981-2000 interval. This collection is hosted in the W@DIS information system (wadis.saga.iao.ru). Most of the ordinates of the plots belong to three groups of functions describing the dependence of the absorption coefficient and the transmission function on wavenumber, the dependence of the absorption coefficient on temperature and the correction factor c for the frequency-dependent Lorentz contour. The article describes two ways to find plots in the collection: a simple search by three publication attributes and an attribute search by 14 properties, including the properties of a primitive plot, substance, and function parameters and properties of an information resource and publication. Such a search is necessary for users to find the desired primitive plots, and is used when combining primitive plots into a compound plot taking into account the user's requirements.

This study presents an accuracy assessment of the forecasts of hazardous convective weather events made with the WRF v.4.2 atmospheric model for Perm region and adjacent area for the period from May 4 to August 25, 2021. The WRF model forecasts had a 27-h lead time; the model grid step was 5 km. To reduce the probability of false alarms, scale-dependent parameterization of convection was used. The sample of squalls and large hail events was compiled based on the weather station reports, damage reports, and satellite images of forest damage. It includes 56 events. The sample of heavy rainfall events was compiled from the weather stations data only. For the same period, the WRF model predicted 30 squalls events (³ 25 m/s^-1) and 63 heavy rainfall events (³ 30 mm/h). Supercells and tornado events are also considered. For squall events, we performed a cross-validation of the simulated and observed events using the distance (50 km) and time (± 3 h) threshold criteria. The accuracy of heavy precipitation was evaluated using the SCI and EDI indices. Overall, the forecasts accuracy for heavy precipitation was unsatisfactory. For squall events, 36% of them were successfully predicted, including the events that caused most substantial damage. Despite the high proportion of event omission (which prevail over false alarms), the forecasts of squalls with the WRF model in this configuration may be useful in preventing damage.

We analyze the process of an increased, in comparison with other regions, rate of warming in the Arctic Ocean and adjacent areas. The visible aspect of the cause of the phenomenon is a decrease in the average thickness of ocean ice and, as a consequence, an increase in the flow of heat from the water through the ice, which heats the lower air layer. In addition, in the process of losing the ice mass of perennial floating glaciers, the heat consumption for their melting decreases. The combined effect of these two factors has provided the current rise in temperature in the polar zone, in a linear approximation, by more than 8 °C. Note that inter-latitudinal air heat exchange does not intensify in this process due to a decrease in meridional temperature gradients.