The dynamical coupling of the lower and upper atmosphere by planetary waves (PWs) is studied. Numerical simulations of planetary wave (PW) amplitudes during composite sudden stratospheric warming (SSW) events in January-February are made using a model of general circulation of the middle and upper atmosphere with initial and boundary conditions typical for the westerly and easterly phases of quasi-biennial oscillation (QBO). The changes in PW amplitudes in the middle atmosphere before, during and after SSW event for the different QBO phases are considered. Near the North Pole, the increase in the mean temperature during SSW reaches 10–30 K at altitudes 30–50 km for four pairs of the model runs with the eQBO and wQBO, which is characteristic for the sudden stratospheric warming event. Amplitudes of stationary PWs in the middle atmosphere of the Northern hemisphere may differ up to 30% during wQBO and eQBO before and during the SSW. After the SSW event SPW amplitudes are substantially larger during wQBO phase. PW refractivity indices and Eliassen-Palm flux vectors are calculated. The largest EP-fluxes in the middle atmosphere correspond to PWs with zonal wavenumber m=1. Simulated changes in PW amplitudes correspond to inhomogeneities of the global circulation, refractivity index and EP-flux produced by the changes in QBO phases. Comparisons of differences in PW characteristics and circulation between the wQBO and eQBO show that PWs could provide effective coupling mechanism and transport dynamical changes from local regions of the lower atmosphere to distant regions of the upper atmosphere of both hemispheres.
Original languageEnglish
Pages (from-to)201-209
Number of pages9
JournalJournal of Atmospheric and Solar-Terrestrial Physics
Volume171
DOIs
StatePublished - Jun 2018

    Scopus subject areas

  • Earth and Planetary Sciences(all)
  • Geophysics
  • Space and Planetary Science
  • Atmospheric Science

    Research areas

  • circulation modeling, middle and upper atmosphere, planetary waves, orographic gravity waves, parameterization, sudden stratospheric warming, Middle and upper atmosphere, Planetary waves, Numerical simulation, Sudden stratospheric warming, Quasi-biennial oscillation, CIRCULATION, MIDDLE ATMOSPHERE, TIDAL EQUATIONS, SIMULATION, VARIABILITY, MODES, DYNAMICS

ID: 7731085