Home – Home – Jornals – Atmospheric and Oceanic Optics 2017 number 2

In the report results of the first field experiments on multiple-address bistatic (over-the-horizon, non-line-of-sight (NLOS)) optoelectronic communication systems in the UV wavelength range performed at the IAO SB RAS are considered. Experimental estimates of the error probabilities and their standard deviations are presented.

Eleven resonance functions of the theory of the broadening of molecular lines by foreign atomic gases are calculated for very low temperatures. These functions correspond to the atom-atom potential and to the potential V ( R , ) written as a series in Legendre functions. The functions are presented in the analytical form. The calculations of the broadening coefficients g are performed for the CO lines perturbed by the He and Ar for the temperatures T from 300 to 2 K. It is shown that the dependence g( T ) for low temperatures T is determined by the deep of the potential. For CO-He system the comparison with the experimental data is presented.

We suggest a technique for preparing nanoporous samples with adsorbed gas for the spectrometric experiments, which allows one to determine the concentration of the absorbed sample gas molecules using a buffer chamber of a large volume in the vacuum system. We also suggest a method which allows a decrease in the sample cleaning time from the absorbed molecules by about an order of magnitude comparing with the sample cleaning time at a room temperature using simultaneous pumping and contactless gas sample heating by radiation of a halogen lamp. The technique and the method tested in simple laboratory experiments of water vapor sorption by silicon (SiO₂) airgel.

FIRE-ARMS software was supplemented with the vector radiative transfer model VLIDORT. The new version of the software allows a simulation of the outgoing thermal infrared radiation (TIR) from Earth and solar short infrared radiation (SWIR) reflected from the surface, taking into account multiple scattering for the same model and atmospheric sensing geometry. We performed spectra simulation of the outgoing radiation in TIR and SWIR with multiple scattering in a cloudless atmosphere and comparison of the spectra simulated with the spectra measured by GOSAT satellite spectrometers in cloudless atmosphere over Western Siberia. Calculated weighting functions show that simultaneous use of TIR and SWIR will improve the height resolution in vertical profiling of methane concentrations in the atmosphere.

The model of the atmosphere in the form of thin homogeneous layers is considered, which is converted into two homogeneous layers without changing the power of the outgoing radiation in the studied spectral region of the methane absorption bands 1220-1260 cm^-1. The observed distortion of the spectrum of outgoing radiation of the Earth with consideration of atmospheric model in an equivalent homogeneous layer does not affect the correlation analysis. The system of equations relating changes of methane content in each of the homogeneous layers with the change of power of the outgoing radiation is given.

The spatial distribution and amplitude characteristics of the absorbed power inside multilayer particle-microcapsules consisting of a liquid core and one or more polymer shells when changing the thickness and refractive index of the external shell was studied in detail. The position of the field localization when varying these parameters was defined. This is important for the solution of practical tasks associated with opening the microcapsule shells in appropriate spatial areas.

With the use of ground-based and satellite measurements of carbon monoxide (CO) an analysis of the reason of the increase in CO over European Russia (ER) in the summer of 2016 was carried out. The results showed that the increase in the CO content was due to the long-range transport of combustion products from wildfires in Siberia. Predominant location over the central part of Northern Eurasia of the high-pressure area to the north of the area of low pressure, which is characteristic for the dipole type of atmospheric blocking, contributed to the anomalous transport of CO from east to west.

The dynamics of the surface air layer in the Northern hemisphere is studied by the method of allocation of structures with the use of the air pressure field. The spatial distribution of the fields of monthly average values of pressure in the Northern hemisphere is found and mapped; their dynamics is estimated in the period 1955-2000. The pressure field class distribution maps have been built over the Northern hemisphere and the typical fields were found.

The long-term series of regular measurements of the carbon dioxide concentration in the surface water and СО₂ fluxes in the littoral zone of Lake Baikal has shown that diurnal variations are observed during all open-water period (May through December), which are related to the processes of photosynthetic activity of plankton. In order to isolate the role of photoperiodic process on the background of the effect of many factors of different nature on the change of the concentration of carbon dioxide in the surface water and its fluxes in the atmosphere - water system, the scheme of diurnal behavior of the concentration and fluxes of CO₂ in the littoral zone of Southern Baikal in 2004-2015 is considered in the coordinates of the sunshine duration. It was calculated on the basis of theoretically possible sunshine duration (from sunrise until sunset under cloudless sky and open horizon conditions). The proposed parameterization algorithm for retrieval of the values of these characteristics for any time moment can be used in the models of the carbon dioxide cycle and will be useful for planning the study of biological and chemical processes in Lake Baikal.

The knowledge of the errors of measurement methods is very important for the assessment of the quality of experimental data. We compare the results of various measurements of total ozone content (TOC) near St. Petersburg between 2009 and 2015. We considere the TOC datasets of ground-based measurements in Voeykovo (Dobson spectrophotometer and M-124 ozonometer) and in Peterhof (Bruker 125HR spectrometer) as well as OMI and IASI satellite measurements. With the aim to assess the errors of the each individual method, we formed three datasets of coincident TOC measurements, depending on the number of comparisons and different criteria for selection. First, we calculated the means and the standard deviation from the means for the TOC differences in pairs of coincident datasets. Second, under the assumption of a horizontally homogeneous and stationary ozone field during each day of measurements, we assessed the random and systematic errors of the individual methods. The mean random error of the TOC measurements totals 2.9 ± 0.5%, 2.8 ± 0.7%, 1.2 ± 0.2%, and 1.4 ± 0.1% for IASI, M-124, OMI, and Bruker 125HR, respectively. The systematic error relative to the standard Dobson measurements amounts to -1.7% and -2.1% for OMI and IASI, respectively, and is equal to + 0.5% and + 2.1% for M-124 and Bruker 125HR, respectively. OMI and Bruker 125HR TOC measurement errors are resistant to atmospheric condition, whereas errors of IASI and M-124 TOC measurements are highly dependent on the state of atmosphere.

A system has been developed to monitor anthropogenic pollutions of remote inaccessible wetlands in the northern oil-producing areas of the Tomsk region. It combines the use of geoinformation and remote technologies with laboratory investigations. To assess the scale of pollution and identify pollutants and processes of hydrocarbon transformation we used simulation techniques based on the analysis of the materials obtained in field investigations and processing of ASTERGDEM and Landsat satellite data. The state of vegetable cover has been estimated depending on the pollutant concentrations and the activity of biocenosis enzymatic system. A normalized difference vegetation index (NDVI), which reflects the vitality of the vegetation in the polluted area, has been calculated, as well a pollution factor of small rivers flowing through the territory of the Sovetskoye oilfield. We have mapped catchment area of the Vasyugan river, tributary of the Ob river, with a high risk of pollution, where there are nearly 400 sites of the pipeline crossings through a network of small rivers - tributaries of the Vasyugan river. The values obtained were proved by the data of physicochemical and microbiological analyses of the soil and water sampled in the area under study. The number and destructive activity of soil microflora has been determined depending on the pollutant concentrations.

The article presents primary results of the study of sediments in the composition of the snow cover background territories of taiga zone of European North-East of Russia using the method of dynamic light scattering. The average size of particles in the snow is 828 ± 311 nm, and the average volumetric fraction of particles less than 1000 nm in samples of melt water is 66.6%. Spatial differentiation in the distribution of particle sizes in the snow of the areas under study is detected. The conclusion about the possible impact of the relief on the granulometric composition of the particles is made. The relationship between the content of elements in suspended particles of snow and their size fractions is shown.