Vol 55, No 3 (2019)

ARTICLES
Radiative instability of a barotropic jet flow in a stratified rotating atmosphere
Kalashnik M.V.
Abstract

The problem of the stability of a jet flow with a piecewise linear velocity profile in a stratified rotating atmosphere is considered. The linearized system of equations for perturbations is reduced to a single equation with respect to the amplitude of the longitudinal velocity component containing the turning points. In terms of Airy functions, an asymptotic solution of the equation is constructed that is valid for small values of the Rossby number. It is shown that the flow becomes unstable due to radiation of inertial-gravitational waves. An analytical expression is obtained for the growth rate of perturbations.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(3):3-10
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Phase shift between changes in global temperature and atmospheric Co2 content under the external emissions of greenhouse gases into the atmosphere
Muryshev K.E., Eliseev A.V., Denisov S.N., Arzhanov M.M., Timazhev A.V.
Abstract

The phase shift between changes in the global surface temperature Tg and atmospheric CO2 content has been shown earlier not to characterize causal relationships in the Earth system in the general case. Specifically, the sign of this phase shift under nongreenhouse radiative forcing changes depends on the time scale of this forcing. This paper analyzes the phase shift between changes in the global surface temperature Tg and the atmospheric CO2 content qCO2 under synchronous external emissions of carbon dioxide and methane into the atmosphere on the basis of numerical experiments with the IAP RAS climatic model and a conceptual climate model with carbon cycle. For a sufficiently large time scale of external forcing, the changes in qCO2 lag relative to the corresponding changes in Tg.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(3):11-19
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The forecast of erythemal UV irradiance over the territory of Northern Eurasia according to the INM-RSHU chemical-climate model
Pastukhova A.S., Chubarova N.E., Zhdanova Y.Y., Galin V.Y., Smyshlyaev S.P.
Abstract

In this work, the impact of various factors on the total ozone column and erythemal UV radiation (Qery) in the territory of Northern Eurasia for the period from 1979 to 2059 based on the calculations of the chemical-climate model INM-RHSU is analyzed. The sensitivity of ozone recovery to the setting of different input data on sea surface temperature (SST) is estimated. Depending on the SST datasets, there are significant differences in ozone trends. A possible mechanism that explains the reasons for these differences is examined. The numerical experiment with the only change in ozone depleting substances according to Montreal protocol showed the ozone recovery and, as a result, Qery reduction, but this recovery is not linear. During the 2016-2020 period we estimated the 2-5% increase in Qery values relative to the baseline period (1979-1983) with about 6% maximum over Russian polar region. During the 2035-2039 period the Qery change against 1979-1983 period is about zero, during the 2055-2059 period we obtained the decrease of about 4-6% over Northern Asia and 6-8% over Northern Europe These changes corresponded to the noticeable boundary location shift of UV resources, which determine UV radiation impact on human health. The most significant changes will be observed in spring and summer: the UV deficiency zone will be expanded in the north and the UV excess zone over northern seas will be reduced in the south.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(3):20-28
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Dynamics of convective upwelling of large-scale weakly heated atmospheric aggregates
Chernogor L.F.
Abstract

Equations for the center-of-mass speed of the parcel of heated air, the mass of the entrained cool air, and the resulting buoyancy of the entire air aggregate have been used to obtain exact and approximate relations for describing height and temporal dependences of the characteristic radius, the excess relative temperature, and a weakly heated large-scale (hundreds of meters and greater) air aggregate convective upwelling. It is shown that the excess temperature relaxation in the air aggregate occurs quickly, the aggregate radius increases slowly and insignificantly. The variations in the center-of-mass speed of the aggregate are not monotonous. First, the speed increases from zero to a maximum value, and then it decreases to zero. Numerical simulations have been performed for the case of interest to practical applications.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(3):29-35
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Vortex motion due to differential diffusion
Ingel L.K.
Abstract

Convection caused by the double (differential) diffusion in a rotating medium can lead to a transfer of vorticity, and in particular, to its concentration. In geophysical applications, it is not considered usually, because the spatial and temporal scales of such convection and rotation effects differ greatly – the period of planetary rotation is many orders of magnitude greater than the characteristic time of existence of the corresponding convective structures in sea water. The paper draws attention to the fact that in the atmosphere there are possible the processes, in which a noticeable transfer of vorticity, caused by the difference in the effective exchange coefficients for various substances, seems to be more real. Effects of the type of double diffusion in the air are possible in principle, in connection with some difference in the rates of heat, water vapor and (or) heavy admixture transfer. The simplest linear model of convection due to double diffusion in a rotating medium is considered. The possibility of the contribution of such effects to the concentration of vorticity during the tornado formation is discussed.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(3):36-40
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Eurasia large-scale hazes in summer 2016
Gorchakov G.I., Sitnov S.A., Karpov A.V., Gorchakova I.A., Gushchin R.A., Datsenko O.I.
Abstract

Using maximum aerosol optical depth (MAOD) spatial distribution formation technique the optically dense haze expansion scales in period from 15 to 31 July 2016 over Eurasia are estimated in during great Siberian smoke haze (SSH) with the area 16 mln km2 about, smog over the Northern China Plain (2 mln km2), dust haze in Takla Makan desert (0.8 mln km2) and hazes in India and Pakistan (1 mln km2 approximately). Empirical distribution function (EDF) MAOD is received which is approximated by linear function of MAOD logarithm. Aerosol optical depth (AOD) spatial distribution at wavelength 550 nm in SSH is analyzed. Total smoke aerosol mass assessment in SSH (3.2 mln tons) is evaluated. Smoke aerosol (SA) mass during maximum growth period from 22 July to 26 July 2016 over Siberia (50°-70°, 60°-120 °E) was equal 2 mln tons approximately. Aerosol index (AI) temporal variability is illustrated visually SA composition qualitative change in SSH during long-range transport. It is shown that AI variations are correlated with AOD variations. Aerosol radiative forcing (ARF) at the top and the bottom of the atmosphere over Siberia from 22 July to 26 July 2016 is estimated (average ARF are equal –68 and –98 W/m2). EDF AOD and EDF ARF at the top of the atmosphere are approximated by exponential and power function of AOD correspondingly.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(3):41-51
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Sulfate sources in carbonaceous aerosol particles in urban atmosphere (on the example of Irkutsk)
Yermakov A.N., Aloyan A.E., Arutyunyan V.O.
Abstract

According to the monitoring data, it was found that the main source of sulfates in carbonaceous particles in the atmosphere of Irkutsk is sulfur dioxide captured from the air. Their accumulation in the particles is caused by heterogeneous chemical reactions (GHR) and is accompanied by the replacement of hydrocarbonates (HCO3 –) with sulfate anions. In this case, sulfur dioxide is oxidized by ozone in the dry atmosphere, and hydrogen peroxide (H2O2) also participates in the humid, along with dissolved ozone, during the oxidation of sulfur dioxide. The details of the mechanisms of these GHR are discussed and estimates of the dynamics of the sulphate production in carbonaceous particles are given.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(3):52-61
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About some similar regularities of cyclonic and seismic activity
Yaroshevich M.I.
Abstract

Similar regularities of cyclonic and seismic activity are revealed. The information base of the research was tropical cyclones and earthquakes in the northwestern part of the Pacific Ocean.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(3):62-66
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Evolution of the fine structure of the pattern of the distribution of a substance of the free-fall droplet in mixing liquids
Chashechkin Y.D.
Abstract

The evolution of the pattern of the substance of a drop of ink falling freely into quiet water in the mode of formation of a cumulative back jet stream was traced by high-speed video recording. In the phase of primary contact and coalescence, the pigment of the drops merging with the targeted fluid is distributed in the form of fine fibers (ligaments), which form a regular striped pattern on the surface of the growing crown, and a net pattern consisting of three-, four- and pentagonal cells at the bottom of the cavity. The fibrous distributions of the substance droplets was saved at all subsequent stages of the evolution of the flow until the formation of a cascade of vortices, after which the picture is blurred by the processes of molecular diffusion in a practically quiescent liquid. The formation of a discrete (fibrous) pattern of the distribution of the substance of a drop is associated with the compactness of the region of release of the available potential surface energy during the confluence of liquids, which initiates a fast movement of a thin layer. Subsequent preservation of fibers ensures the slowness of molecular diffusion processes.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(3):67-77
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Internal tides in the strait of Denmark
Morozov Е.G., Frey D.I., Gladyshev S.V., Klyuvitkin А.А., Novigatsky А.N.
Abstract

Six day temperature records carried out at the three mooring levels revealed isotherm fluctuations in the Denmark Strait sill in July 2018 caused by internal waves. In addition to the field measurements, fluctuations of isopycnals were estimated on the basis of a numerical model. It was shown that the vertical displacements of water particles caused by semidiurnal internal tides are approximately 50 m in the region of the sill crossing the strait. The displacements decrease to 30 m over a distance of 100 km from the sill. The internal waves in the northern part of the strait are more intense than in the southern part because the wave propagates in the opposite direction to the mean current. In the southern part the waves and the current propagate to the south, which increases the wavelength and decreases their amplitudes.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(3):78-84
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