TY - JOUR

T1 - On statistical irregularity of stratospheric warming occurrence during northern winters

AU - Savenkova, E. N.

AU - Gavrilov, N. M.

AU - Pogoreltsev, A.I.

PY - 2017/10

Y1 - 2017/10

N2 - Statistical analysis of dates of warming events observed during the years 1981–2016 at different stratospheric altitudes reveals their non-uniform distributions during northern winter months with maxima at the beginning of January, at the end of J anuary – beginning of February and at the end of February. Climatology of zonal-mean zonal wind, deviations of temperature from its winter-averaged values, and planetary wave (PW) characteristics at high and middle northern latitudes in the altitude range from the ground up to 60 km is studied using the database of meteorological reanalysis MERRA. Climatological temperature deviations averaged over the 60–90 N latitudinal bands reveal cooler and warmer layers descending due to seasonal changes during the polar night. PW amplitudes and upward Eliassen-Palm fluxes averaged over 36 years have periodical maxima with the main maximum at the beginning of January at altitudes 40–50 km. During the above-mentioned intervals of more frequent occurrence of stratospheric warming events, maxima of PW amplitudes and Eliassen-Palm fl uxes, also minima of eastward winds in the high-latitude northern stratosphere have been found. Climatological intraseasonal irregularities of stratospheric warming dates could indicate reiterating phases of stratospheric vacillations in different years.

AB - Statistical analysis of dates of warming events observed during the years 1981–2016 at different stratospheric altitudes reveals their non-uniform distributions during northern winter months with maxima at the beginning of January, at the end of J anuary – beginning of February and at the end of February. Climatology of zonal-mean zonal wind, deviations of temperature from its winter-averaged values, and planetary wave (PW) characteristics at high and middle northern latitudes in the altitude range from the ground up to 60 km is studied using the database of meteorological reanalysis MERRA. Climatological temperature deviations averaged over the 60–90 N latitudinal bands reveal cooler and warmer layers descending due to seasonal changes during the polar night. PW amplitudes and upward Eliassen-Palm fluxes averaged over 36 years have periodical maxima with the main maximum at the beginning of January at altitudes 40–50 km. During the above-mentioned intervals of more frequent occurrence of stratospheric warming events, maxima of PW amplitudes and Eliassen-Palm fl uxes, also minima of eastward winds in the high-latitude northern stratosphere have been found. Climatological intraseasonal irregularities of stratospheric warming dates could indicate reiterating phases of stratospheric vacillations in different years.

KW - Climatology

KW - sudden stratospheric warming

KW - zonal-mean wind

KW - temperature, planetary wave activity, dynamical regime of the stratosphere

U2 - 10.1016/j.jastp.2017.06.007

DO - 10.1016/j.jastp.2017.06.007

M3 - Article

VL - 163

SP - 14

EP - 22

JO - Journal of Atmospheric and Solar-Terrestrial Physics

JF - Journal of Atmospheric and Solar-Terrestrial Physics

SN - 1364-6826

IS - 6

M1 - doi:10.1016/j.jastp.2017.06.007

ER -