Home – Home – Jornals – Atmospheric and Oceanic Optics 2018 number 4

The vibrational-rotational absorption spectrum of water vapor was recorded and analyzed in the visible region from 19480 to 20500 cm^-1. The measurements were carried out at the IFS-125M Fourier spectrometer with a resolution of 0.05 cm^-1 at a pressure of 26.3 mbar, a temperature of (24±1) ^oC at an optical path 24 m long. We used a multipass White cell with a base length of 60 cm. The light-emitting diode was used as the radiation source. The signal-to-noise ratio was about 20000. As a result of the spectrum analysis, a list of more than 420 lines has been formed, which includes line centers and intensity and quantum vibrational-rotational identification. More than 220 vibrational-rotational energy levels of 21 upper vibrational states have been determined.

The dependence of the intermolecular interaction potentials for the H₂O-Ne, H₂O-Kr, and H₂O-Xe systems on the vibrational quantum numbers of H₂O molecule is derived. The broadening coefficients γ are calculated for seven vibrational bands ν₁, ν₂, ν₃, 2ν₂, ν₁ + ν₂, ν₂ + ν₃, and ν₁ + ν₂ + ν₃ of H₂O molecule from the region 640-9888 cm^-1. The analytical formula are suggested for the calculated broadening coefficients γ at T = 296 K. It is shown that the excitation of stretching modes of the vibrations in H₂O molecule increases the broadening coefficients γ. The influence of the bending vibrations on γ is insignificant.

The ν₂ band is analyzed on the basis of the combination difference method. The high resolution FTIR spectrum of the SO₂ molecule in the region 400-700 cm^-1 is used for the analysis. More than 4500 lines with the maximum values of the quantum numbers J and K_a equal to 96 and 25, respectively, are interpreted. On this basis, 1294 vibrational-rotational energy levels of the state (010) are determined. As a result of solution of the inverse spectroscopic problem with these levels, 32 effective Hamiltonian parameters are obtained, which allow us to reproduce the initial experimental data with the accuracy d_rms = 1.9 ( 10^-4 сm^-1.

Main regularities of the formation of lidar returns in sensing of water depth comprising pelagic fish schools are determined by the Monte Carlo method. Based on the analysis of the results of statistical simulation of depth profiles of lidar signal power and depolarization, a method of polarization laser sensing for sea fish school detection is suggested using the depth profiles of lidar return signal power and depolarization and the natural threshold - the sea water extinction coefficient measured with the lidar.

Variability of the profiles of bioluminescent lighting and chlorophyll  a concentration along the coastal zone of the Crimea and its causes are analyzed using the data of two expeditions and satellite data. It is shown that the bioluminescent lighting and chlorophyll  a concentration are minimal in a vicinity of the deep-sea cyclonic eddy, where the upwelling occurred and the upper mixed layer depth was as small as 20 m. Minima of bioluminescent lighting and chlorophyll  a concentration were observed in the shallow area which is rich in biota.

The verification of the results of WRF-CHEM model simulation of anthropogenic emission distributions over Norilsk industrial zone using airborne sounding data for August 2004 is carried out. The study showed that the selected configuration of the WRF-CHEM v3.5.1 model adequately reproduces the meteorological parameters measured during the campaign of 2004. The simulated distributions of the concentrations of sulphur dioxide and ozone and mass concentration of aerosol qualitatively reproduce the distributions obtained during the airborne sounding. Quantitative estimates show that the standard errors for sulphur dioxide, the mass concentration of aerosol PM_2.5, and ozone calculated for three flights are 23 ppb, 2.6 (g/m³, and 9.8 ppb, respectively. Possible reasons for such discrepancies may be incorrect specification of the initial and boundary conditions, inaccurate values of anthropogenic emissions, and limitations to the aerosol and chemical mechanisms used.

The results of the study of changes in the total solar radiation, cloudiness, sunshine duration, and surface air temperature in Tomsk for the period 1996-2016 are presented. It is shown that decrease in the total solar radiation and sunshine duration and, vice versa, increase in the surface air temperature and total and inferior cloud amount are observed. There is a tendency to increase in the contribution of upper tier clouds and decrease in that of middle layer clouds.

The analysis of the monthly average surface air temperatures for the 1940-2015 period is provided based on observations of a network of meteorological stations in the Southern Urals. The temperature series expansion into empirical orthogonal components (EOC) is used for the study of the spatiotemporal structure. The correlation analysis of the EOC for winter and summer with the main large-scale natural climate variability modes of the Northern hemisphere is carried out. The first leading EOC describes a positive temperature trend and makes the main contribution into the temperature variability. For the winter season, the leading mode is associated with North Atlantic oscillation. For summer, a significant contribution of the Atlantic multi-decadal fluctuation and East-Atlantic-Western-Russian index is revealed; this finding can be used to improve the forecast of climate change in the coming decades for the region under study. In general, the results indicate a significant impact of natural climatic variability on the temperature regime as well as a possible difficulty in isolating the anthropogenic component of climate change in the region.

Based on long-term (2004-2016) expedition studies, statistical generalization and zoning of physical-chemical aerosol characteristics in the Eastern Atlantic (from English Channel to Antarctica) are performed. For six latitudinal zones of the Atlantic and Southern Oceans (> 45(N; 20(-45(N; 0(-20(N; 0(-20(S; 20(-55(S; > 55(S) the average values of the main aerosol characteristics are calculated, i.e., atmospheric AOD, fine and coarse AOD components, particle number concentrations, and mass concentrations of aerosol, black carbon, and water-soluble ions (Na⁺, Mg²⁺, Cl⁽, K⁺, Ca²⁺, NH₄⁺, NO₃⁽, SO₄²⁽), as well as of gas admixtures (SO₂, HCl, HNO₃, NH₃). It is shown that the zonal variability range of optical and microphysical aerosol characteristics is about an order of magnitude: the largest (minimal) average values are observed in the tropical zone (Southern Ocean). The zonal differences (a factor of 1.3 to 4.3) in concentrations of ions and gas admixtures are much smaller and comparable to synoptic variations. The concentrations of “marine” ions are maximal over the Southern Atlantic, and of “continental” ions, in the Northern hemisphere, in tropical and subtropical zones; the concentrations of all ions are minimal over the Southern Ocean. The specific features of geographic distribution of gas admixtures are noted: the maximal concentrations of HCl and NH₃ are observed over the Southern Atlantic, of SO₂ and HNO₃, near Europe, and the lowest level is observed in the tropical zone.

Based on the measurements of light scattering functions performed in different regions of the Lake Baikal in summer 1979, the characteristics of suspended matter in surface waters are calculated, including mass and number concentrations of suspension and its different fractions. By this data, the relationships with Secchi Disk are derived. The formula of relationship between the mass concentration of suspended matter and Secchi Disk for Lake Baikal is compared with similar formulas for marine waters.

Based on the energetic electron precipitation data, obtained using the magnetogram inversion technique (MIT), there were performed model estimates of variations in the night mid-latitude ionosphere parameters for Irkutsk (52(N, 105(E) during the very strong geomagnetic storm on November 20-23, 2003 ( K _р = 9, D _stmax = 472 nT). The derived fluxes of precipitating electrons are able to produce the night electron density with n_e ( 3 ( 10⁶ cm⁽³ and electron temperature T_e ( 4500 K, which can provide the observed magnitude increase in the red line emission due to excitation of atomic oxygen ¹ D level, mainly in collisions of molecular oxygen ions with thermal electrons.

It is shown that the transmission spectrum of a holographic sensor (silver nanograins embedded in a polymer matrix) is well described by expressions for the Rayleigh light scattering and absorption by silver nano-grains. The optical characteristics of the medium are determined in the Maxwell Garnett approximation. In the presence of a holographic structure, a dip appears in the spectrum. The possibility of obtaining the approximating curves depends on the approximation interval. The spectra are well approximated both in the presence and in absence of an interference structure. The dip parameters coincide well in the approximation range, despite the fact that the values of the background parameter associated with the absorption being found in different ranges of approximation can differ significantly.

Typical results of precipitation parameter measurements with the optical precipitation gauge at the IMCES SB RAS meteorological site from June to October 2016 are described. The particle size distributions are presented for precipitations of different types. The measured precipitation intensity and daily total values are compared with the data obtained with standard precipitation gauges.