TY - JOUR

T1 - Comparisons of planetary wave propagation to the upper atmosphere during stratospheric warming events at different QBO phases

AU - Koval, A. V.

AU - Gavrilov, N. M.

AU - Savenkova, E. N.

AU - Погорельцев, Александр Иванович

PY - 2018/6

Y1 - 2018/6

N2 - 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.

AB - 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.

KW - circulation modeling

KW - middle and upper atmosphere

KW - planetary waves

KW - orographic gravity waves

KW - parameterization

KW - sudden stratospheric warming

KW - Middle and upper atmosphere

KW - Planetary waves

KW - Numerical simulation

KW - Sudden stratospheric warming

KW - Quasi-biennial oscillation

KW - CIRCULATION

KW - MIDDLE ATMOSPHERE

KW - TIDAL EQUATIONS

KW - SIMULATION

KW - VARIABILITY

KW - MODES

KW - DYNAMICS

UR - http://www.scopus.com/inward/record.url?scp=85018408966&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/comparisons-planetary-wave-propagation-upper-atmosphere-during-stratospheric-warming-events-differen

U2 - 10.1016/j.jastp.2017.04.013

DO - 10.1016/j.jastp.2017.04.013

M3 - Article

VL - 171

SP - 201

EP - 209

JO - Journal of Atmospheric and Solar-Terrestrial Physics

JF - Journal of Atmospheric and Solar-Terrestrial Physics

SN - 1364-6826

ER -