Selected publications since 1991

Shved G.M., Petrova L.N. and Polyakova O.S. Penetration of the Earth's free oscillations at 54 minute period into the atmosphere. Annales Geophysicae 18, No.5, 566-572, 2000.
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  • Abstract - It is known that the fundamental spheroidal mode 0S2 of the Earth free oscillation with the period of about 54 min forces atmospheric oscillations. We present a certain phase relationship for components of the 0S2 multiplet, which is based on synchronous collocated microbarograph and seismograph observations. This relationship is both the first observational manifestation of the Pekeris mode of global atmospheric oscillations with the 54 min period and a further proof of penetrating the Earth's 0S2 mode into the atmosphere. We show that the linear non-dissipative model of steady forced oscillations in isothermal atmosphere at rest does not describe penetrating the 0S2 mode into the atmosphere adequately.
  • Petrova L.N. and Shved G.M. Revealing Short-Period Global Oscillations of the Atmosphere from Seismic Observations. Izvestia, Atmos. Ocean. Phys. 36, 64-67, 2000.

  • Abstract - A discrete spectrum of seismic oscillations was obtained in the range of periods 1-2 h. These oscillations were recorded in St.-Petersburg (60o N, 30o E) by a seismometer with a vertical pendulum. The frequency distances between the harmonics of this spectrum are in agreement with the theory of short-period free oscillations of the atmosphere of the Lamb-wave type.
  • Ogibalov V.P., Kutepov A.A. and Shved G.M. Non-local thermodynamic equilibrium in CO2 in the middle atmosphere. II. Populations in the n1n2 mode manifold states. J. Atmos. Solar-Terr. Phys. 60, 315-329, 1998.

  • Abstract - The NLTE problem for the v1v2 mode manifold states of CO2 molecules has been solved using the HITRAN-92 database of spectroscopic parameters and new rate constants for V-T and V-V collisional processes. The effect of the vertical kinetic te mperature and O mixing ratio profiles on the vibrational temperatures has been investigated in detail, as has the effect of solar pumping. We show that accounting for transitions with the state change of two- and more v2 -quanta during CO2-O collisions in the lower thermosphere can increase the vibrational temperature of doubly and triply excited states of the v2 mode by as much as several tens of degrees Kelvin relative to the one- v2 -quantum transitions commonly used to calculate state populations.
  • Shved G.M., Kutepov A.A. and Ogibalov V.P. Non-local thermodynamic equilibrium in CO2 in the middle atmosphere. I. Input data and populations of the v3 mode manifold states. J. Atmos. Solar-Terr. Phys. 60, 289-314, 1998.

  • Abstract - The CO2 NLTE problem has been extended to account for all vibrational states and transitions included in the HITRAN-92 database of spectroscopic parameters. The set of the rate constants for V-T and V-V collisional processes and the model for pumping the CO2 states by OH(v) have been revised. The effect of the vertical kinetic temperature and O mixing ratio profiles on the vibrational temperatures of the v3 mode manifold states as well as the dependence of these temperatures on the solar zenith angle have been examined in detail. In the daytime, the lower boundary of the NLTE layer tends to reach the ground when the energy of the v3 mode manifold states increases.
  • Shved G.M. and Gusev O.A. Non-local thermodynamic equilibrium in N2O, CH4, and HNO3 in the middle atmosphere. J. Atmos. Solar-Terr. Phys. 59, 2167-2176, 1997.

  • Abstract - This paper presents for the first time theoretical estimates of the non-local thermodynamic equilibrium (NLTE) populations for vibrational states of the N2O and CH4 molecules in the stratosphere and mesos phere. For N2O the nighttime heights of the transition to NLTE decrease with vibrational energy from about 70 km for the (0110) state to about 55 km for the states excited in the v3 mode. For daytime the vibrational temperatures of the (0001) state and of higher N2O states far exceed those for nighttime. For the N2O (020l, 0221, 100l) states the daytime NLTE layer extends throughout the entire stratosphere. For the first excited states of the CH4 v2 and v4 modes the transition to NLTE occurs near 60 km. The vibration-vibration (V-V) energy exchange with N2 and O2 is important in the mesosphere for populating the N2O and Đ═4 states, respectively. Using the ═NO3 molecule as an example, we propose a simple way of estimating roughly the NLTE population of vibrational states of polyatomic molecules when data on the rate constants of vibration-translation (V-T) and V-V energy transfers are lacking. For the HNO3 states not higher than the v2-state a speculative estimate yields about 50 km as the lower limit for the heights of the transition to NLTE.
  • Petrova L.N., Osypov K.S., Savel'ev D.D. and Shved G.M. Forcing atmospheric oscillations by long-period seismic oscillations: a case study. J. Atmos. Terr. Phys. 58, 1317-1322, 1996.

  • Abstract - Using synchronous measurements made by microbarograph and a seismograph with a vertical pendulum, the sign of the vertical direction of the wave energy flux in the atmosphere at the ground has been derived for oscillations in the ~0. 5-4 h period range and which occur simultaneously in the Earth and atmosphere. The seismic oscillations shown could generate atmospheric oscillations by the Ĺpistonĺ mechanism. A change of sign of the flux direction is also observed.
  • Podgorny I.A. and Shved G.M. On retrieving Rossby waves in the middle atmosphere from measurements of thermal outgoing radiation. J. Atmos. Terr. Phys. 57, 1209-1219, 1995.

  • Abstract - The first step is made in elaborating special methods to retrieve the planetary-scale waves for the stratosphere and mesosphere from measurements of thermal outgoing radiation. The method is adapted for the nadir sounding of Rossby n ormal modes of the Lamb wave type in the 15 micron CO2 band. The main formulae are presented in a dimensionless form. The proposed method consists of EOF filtering to extract a wave-induced signal and of Hermite polynomial expansions to descri be the vertical structure of the wave. The accuracy of the retrievals is estimated; it is dependent on the duration of the record as well as on the number of channels. The method is able to provide a higher accuracy than currently available methods.
  • Fomichev V.I. and Shved G.M. On the closeness of the middle atmosphere to the state of radiative equilibrium: an estimation of net dynamical heating. J. Atmos. Terr. Phys. 56, 479-485, 1994.

  • Abstract - We have evaluated the height profiles of both globally averaged net radiative heating and the global mean temperature for heights between 15 and 110 km for March, June, September, and December. This latter quantity was obtained from the thermal balance equation taking account only of radiative processes and molecular heat conduction. The global mean net dynamical heating, which we assume to be mainly due to net wave heating, has been estimated by using only radiation calculations. This heating as a function of height is wave-like and both positive and negative, its vertical profiles are rather similar for various months, and its absolute value is not more than ~5 K/day below 105 km. We recommend using the evaluated global mean net dynamical heating for the parameterization of net wave heating.
  • Sivkov A.M. and Shved G.M. Influence of latitudinal and longitudinal variations of ozone and water vapour on the solar semidiurnal tide. J. Atmos. Terr. Phys. 55, 815-826, 1993.

  • Abstract - A new tidal source model, based on climatological global ozone and water vapour distributions, has been obtained for January, April, July and October. The source model is used for modelling the solar semidiurnal tide in the lower the rmosphere within the framework of the classical tidal theory. The observed phase quasibimodality of the semidiurnal tide at middle latitudes is possibly formed, to a great extent, by two types of hemispheric asymmetry (changing sharply near the equinox) of the ozone distribution. Near 95 km at middle latitudes, the ozone and water vapour distribution nonzonality yields typical values ~2 m/s for maximum longitudinal variations of the zonal and meridional wind amplitudes, and the range ~0.2-0.5 h f or maximum longitudinal phase variations in the Northern hemisphere, while they can reach ~10 m/s and ~1.5 h in the Southern hemisphere. The hemispheric asymmetry is mainly caused by the effect of the water vapour tidal source.
  • Fomichev V.I., Kutepov A.A., Akmaev R.A. and Shved G.M. Parameterization of the 15 micron CO2 band cooling in the middle atmosphere (15-115 km). J. Atmos. Terr. Phys. 55, 7-18, 1993.

  • Abstract - A new parameterization of the 15 micron CO2 band radiative cooling rate in the middle Earth atmosphere for both LTE (local thermodynamic equilibrium) and non-LTE layers is presented. It includes the parameterization of AKMAEV and SHVED [(1982), J. atmos. terr. Phys. 44, 993] for the 35-70 km layer, which is modified to account for the line overlapping in the band for the 15-35 km layer and for non-LTE effects in the 70-80 km layer. In the non-LTE layer above 80 km a simple recurrence relation between the cooling rates for two neighboring altitude levels is used. For any temperature profile, which has no micro- or meso-scale structure, the absolute error of the parameterization in the 15-80 km layer does not exceed 0.5 ╩ day-1. In the non-LTE 80-115 km layer the error depends on the value of the rate constant for the de-excitation of CO2(0110) by collisions with atomic oxygen O, not exceeding, however, 0.07, 0.4 and 4 ╩ day-1 for values of this constant equal to 5x105, 5x106 and 5x107 s-1atm-1 respectively.
  • Manuilova R.O. and Shved G.M. The 4.8 and 9.6 micron O3 band emissions in the middle atmosphere. J. Atmos. Terr. Phys. 54, 1149-1168, 1992.

  • Abstract - For the 40-115 km atmospheric layer, the populations of 19 vibrational states of the ╬3 molecule have been calculated for sets of vertical profiles of temper ature and concentration of O and ╬3. A peculiar feature of the day and night time vertical profiles of the vibrational temperature of the states is at its maximum in the height range 75-90 km which is due to the formation of vibrationally excited molecules of O3 in the recombination: ╬2+╬+╠ --> O2+M. On the basis of the calculated populations of the states, the limb and downward atmos pheric emissions in the 4.8 and 9.6 micron 3 bands have been estimated, as well as the contributions of the constituents of the band of vibrational transitions.
  • Akmaev R.A., Fomichev V.I., Gavrilov N.M. and Shved G.M. Simulation of the zonal mean climatology of the middle atmosphere with a three-dimensional spectral model for solstice and equinox conditions. J. Atmos. Terr. Phys. 54, 119-128, 1992.

  • AbstractŚThe zonal mean state of the middle atmosphere is simulated by a three-dimensional spectra] model, extending approximately 15 up to 120 km. for solstice and equinox conditions. The model includes realistic parameterizations of atmospher ic infrared cooling, and a gravity wave formulation based on a combination of LINDZENĺS [(1981), J. geophys. Res. 86, 97 07] and MATSUNOĺS [(1982), J. Met. Soc. Ja pan 60, 215] approaches. The temperature distributions for both seasons and the zonal wind distribution for solstice are in satisfactory agreement with the recent empirical model of FLEMING et al. [(1988), NASA Technical Memorandum No. 100697 (85 pp.)].
    Net vertical fluxes of horizontal momentum agree well with available systematic observations of gravity waves in the middle atmosphere. Dissipating and breaking waves yield heating rates comparable with net radiation heating in the upper mesosphere and lower thermosphere. Low values of the vertical eddy diffusion coefficient of order 30-50 m2 s-1 are necessary to produce realistic temperatures around the mesopause.
  • Shved G.M., Khvorostovskaya L.E., Potekhin I.Yu., Demynikov A.I., Kutepov A.A. and Fomichev V.I. Measurement of the quenching rate constant for collisions CO2(0110)-O: the importance of the rate constant magnit ude for the thermal regime and radiation of the lower thermosphere. Izvestia, Atmospheric and Oceanic Physics. 27, 431-437 (Russian version), 1991.

  • Abstract - For the first time, the rate constant of the quenching of CO2(0110) by atomic oxigen has been measured for atmospheric temperatures ~ 300 K ( in gas discharge with a hollow cathode). T he lage magnitude obtained (~ 3.5 107 s-1 Î atm-1) has the following consequences: 1) Cooling in the 15 micron CO2 band can en tirely compensate solar heating of the 90-100 km layer on a globally averaged basis, decreasing considerably the importance of eddy heat conductivity as an energy sink; 2) For the lower thermosphere, it should be assumed that there is a strong relationship between the degree of O2-decomposition (in O) and atmospheric temperature and circulation; 3) The lower thermosphere radiance in the 15 micron CO2 band depends greatly on the mixing ratio for O.á