Vol 55, No 2 (2019)

ARTICLES
Bulk models of sheared boundary layer convection
Debolskiy A.V., Stepanenko V.M., Glazunov A.V., Zilitinkevich S.S.
Abstract

The paper discusses approaches to the construction of integral models of the convective boundary layer (CBL), based on the concept of complete mixing. To test analytic bulk models and the basic hypotheses of similarity, we use the results of eddy modeling (LES – Large Eddy Simulation). The empirical constants of the CBL integral models obtained according to the LES data for the case of free convection, are in good agreement with the previously published data of laboratory experiments. It is also shown that the flow of kinetic energy from the upper boundary of the CPS, carried out by gravitational waves, is small compared with other components of the balance of turbulent kinetic energy (TKE) in the convective layer. Parametrization of TKE generation for the case of sheared convective boundary layer in terms of the friction velocity and the average wind velocity in the CBL derived; resulting dimensionless constants are obtained from LES data. The results of the work allow us to formulate an integral model of the shear KPS suitable for practical use.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(2):3-16
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Organized roll circulation and transport of mineral aerosols in the atmospheric boundary layer
Vazaeva N.V., Chkhetiani O.G., Maksimenkov L.O.
Abstract

Investigation of roll circulations and its transport characteristics in the atmospheric boundary layer (ABL) is carried out. The case study in Kalmykia, 28 of July, 2007, where the equipment measurements have been conducted by A.M. Obukhov Institute of Atmospheric Physics, is analyzed with the use of WRF-ARW model. The evolution of the circulation with considerable asymmetry in the positive and negative velocity and helicity components is registered. The rolls is sign out by the intensification of the dust picking up and accumulation from underlying terrain, and along with intensive vortices with vertical axis become the significant source of atmospheric pollutants. Captured fine aerosols can be transported by long distances and form the aerosol layers.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(2):17-31
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Internal gravity and infrasound waves during a hurricane in Moscow On May 29, 2017
Kulichkov S.N., Chunchuzov I.P., Popov O.E., Perepelkin V.G., Golikova E.V., Bush G.A., Repina I.A., Tsybulskaya N.D., Gorchakov G.I.
Abstract

The results of recording of internal gravity waves (IGWs) and infrasound waves from the warm and cold fronts associated with the atmospheric storm passing through Moscow on May 29, 2017 are presented. The waves were recorded by a network of 4 microbarographs IFA–MGU–MSR–ZNS located in Moscow and Moscow region, and compared with the data of measurements of the parameters of infrasound waves at infrasound station IS43 in Dubna. We study the temporal changes in the characteristics of IGWs and infrasound waves (coherence, direction of propagation,phase velocities, characteristic periods and frequency spectra) with the passage of warm and cold fronts through the network. The transition from the gravity to the acoustic dispersive branch of acoustic-gravity waves due to an increase in frequency and the temporal modulation of the phase velocity of infrasound waves caused by IGWs are also studied. The measurement data for PM10 aerosol concentrations and NO2 gas concentrations at various locations in Moscow during a passage of atmospheric storm are presented. The possibility of detecting wave precursors of atmospheric storms simultaneously in variations of atmospheric pressure, wind velocity and aerosol concentrations is studied.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(2):32-40
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Tidal and planetary waves in the lower thermosphere and ionosphere simulated with the EAGLE model for January 2009 sudden stratospheric warming conditions
Vasiliev P.A., Bessarab F.S., Karpov I.V., Klimenko V.V., Klimenko M.V., Sukhodolov T.V., Rozanov E.V.
Abstract

This paper presents the analysis of planetary waves and tidal variability during January 2009 in the mesosphere, thermosphere, and ionosphere simulated with two versions of the EAGLE model. It is shown that sudden stratospheric warming (SSW) occurred in January 2009 leads to an increase in the planetary and tidal wave activity in the lower thermosphere. The features of the solar-migrating and non-migrating components of tidal variations in the thermosphere, ionosphere, and electric fields are considered. The reproduction of the vertical electromagnetic drift during the SSW period over the Jicamarca station is explained by a significant increase in the diurnal and semi-diurnal tidal activity.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(2):41-50
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The tidal effect on the climatic characteristics of the Kara Sea in the ice-free period
Kagan B.A., Sofina E.V., Timofeev A.A.
Abstract

Using a high-resolution version of the QUODDY-4 three-dimensional finite-element hydrostatic model, we have carried out two series of numerical experiments. The first estimates tidal changes characterizing the role of tides in the formation of climatic characteristics of the Kara Sea in the ice-free period (the magnitude and directions of velocity of permanent surface currents, temperature, and salinity at the pycnocline base and level of the free sea surface). The second series checks the adequacy of the indirect description of tidal changes in terms of tide-induced baroclinic tidal-energy dissipation and diapycnal diffusion when compared to the explicit method and obtains a quantitative measure that can be used for their comparison. The modeling results indicate, first, that the tidal changes are a significant, if not key, factor; second, that the indirect description of tidal changes is adequate when compared to the explicit method; third, that it is unjustified to disregard these changes (this is common in predicting and computing the climates of marine systems); and, finally, that the correlation averaged over the sea surface area can be taken as a quantitative measure of the similarity of the fields of climatic characteristics obtained for the total (wind + thermohaline + tidal) forcing, on the one hand, and the combined (wind + thermohaline) forcing coupled with the indirect method for the description of tidal changes, on the other.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(2):51-60
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Estimates of the turbulence intensity and power density of an asymmetrical tidal flow under variability of wind forcing
Korotenko K.A., Sentchev A.V.
Abstract

A high-frequency (1.2 MHz) four-beam Acoustic Doppler Current Profiler (ADCP) moored on the seabed has been used for direct measurements of turbulence in a shallow coastal zone of the eastern English Channel. From the measurements conducted, 5 tidal cycles covering calm and storm periods were selected. Impacts of the tidal cycle asymmetry and the variability of wind forcing on the turbulence intensity, Reynolds stresses, and the power density of the flow are assessed quantitatively. A comparison of the energy characteristics of the tidal flow during calm and storm periods revealed that the power density of the stream during the storm was about half of that during the calm period. Wave bias correction of Reynolds stresses allows estimating a contribution of small-scale turbulence to its total intensity.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(2):61-72
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Description of the perturbations of oceanic geostrophic currents with linear vertical velocity shear taking into account friction and diffusion of density
Kuzmina N.P., Skorokhodov S.L., Zhurbas N.V., Lyzhkov D.A.
Abstract

A spectral problem of Orr-Sommerfeld type for describing stable and unstable disturbances of oceanic geostrophic flows with linear vertical velocity shear is considered. Calculations of eigenvalues, increments of growth rate of unstable modes, and eigenfunctions of the fastest growing disturbances are presented. It is found that the instability of the flow is observed over a wide range of horizontal scales: in addition to long-wave perturbations with a phase velocity exceeding the maximum flow velocity and perturbations with scales of the Rossby radius, short-wave modes with scales much smaller than the Rossby radius (sub-mesoscale structures) exist. The results of the model are used to describe intrusions in the Arctic basin, which are observed under conditions of absolutely stable stratification.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(2):73-85
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Model of the windward slope formation of the eolian relief form
Malinovskaya E.A.
Abstract

The model for establishing the windward slope upon exposure to the air flow is based on the analysis of the state of the layer composed of sandy incoherent particles. It is assumed that the wind removal of individual particles of this layer leads to a change in its length due to rolling and immobility of larger particles. Accounting for precipitating saltating particles gives an idea of the reasons for the alternation of layers of large particles with layers of smaller ones involved in wind-sand transport. Assuming a linear dependence of the dynamic velocity on the height of the location on the windward slope, the forms of the windward slope, which are close to the observed ones, are obtained. An algorithm for determining the linear coefficient of change of dynamic velocity is proposed. The calculation of the relative change at different levels of the windward slope of the values of the roughness parameter and the scale of the laminar layer made it possible to estimate the coefficient of surface resistance.

Известия Российской академии наук. Физика атмосферы и океана. 2019;55(2):86-95
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