The Influence of the 11‐year Sunspot Cycle on the Atmospheric Circulation During Winter

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AbstractBased on reanalysis data of the meteorological field and sunspot cycle index, the influences of the 11‐year sunspot cycle (SSC) on stratospheric and tropospheric circulation during winter (November to March) in the northern hemisphere are investigated by using statistical analysis and dynamical diagnosis. According to the east or west phase of stratospheric equatorial zonal wind quasi biennial oscillation (QBO), we have analyzed the solar effects in different situations. In east QBO phases, the solar effects focus on the equatorial upper stratosphere and southern hemispheric stratosphere, where enhanced solar ultraviolet radiations heat up the stratospheric ozone layer, leading to increase of the temperature apparently. The solar maxima events reinforce the southern stratospheric Brewer‐Dobson circulation, and result in warming of the southern polar areas. The planetary wave plays a significant role in high latitudes regions of the northern hemisphere, hence the solar cycle signals could be nearly neglected. In west QBO phases, solar effects are more important in north hemisphere. In early winter, solar maxima effects are not only warming the equatorial stratospheric ozone, but also restraining the northern atmospheric B‐D circulation, leading to increase of the equatorial stratospheric temperature and zonal wind gradient change, hence the two waveguides of planetary wave are altered after those processes. In late winter, the polar waveguide of planetary wave is enhanced by solar effects and the B‐D circulation is recovered gradually. After these procedures the temperature of northern polar stratosphere starts to increase conspicuously, accompanied by the decrease of equatorial zonal temperature.