Response of the Southern Hemisphere Atmosphere to the Stratospheric Equatorial Quasi-Biennial Oscillation (QBO) from Winter to Early Summer

[摘要]  We investigate the effects of the stratospheric equatorial quasi-biennial oscillation (QBO) on the extratropical circulation in the Southern Hemisphere (SH) from SH winter to early summer. The Japanese 55-year Reanalysis (JRA-55) dataset is used for 1960-2010. The factors important for the variation of zonal wind of the SH polar vortex are identified via multiple linear regression, using equivalent effective stratospheric chlorine (EESC), middle- and lower-stratospheric QBO, solar cycle, El Niño-Southern Oscillation (ENSO), and volcanic aerosol terms as explanatory variables. The results show that the contributions to the SH polar vortex variability of ENSO are important in SH early winter (June) to mid-winter (July), while that of middle-stratospheric QBO is important from spring (September to November) to early summer (December).

[学科分类] 大气科学

[关键词] quasi-biennial oscillation;Southern Hemisphere polar vortex;multiple linear regression