QBO cycle identified by changes in height profile of the zonal winds: new regularities

The vertical wind profiles in the equatorial atmosphere for 1953-2003 have been examined to study the regularities of the wind reversal in quasi-biennial oscillations (QBO) cycle. The detail analysis of rotation in the stratospheric wind profiles reveals that the quiet periods alternate with active periods, characterized by strong disturbing winds. The stage with the easterly winds above 20-30 hPa and westerly winds lower this layer (Stage 1) always starts in solstice months and can last during 3-4, 9-10, or 15-16 months with no essential changes in the wind profile. Then, the disturbing winds are developed in layer below 20-30 hPa during the nearest equinox. It takes 20-21 months for next 7 stages and the wind profile with the easterly winds above and westerly winds below 20-30 hPa (Stage 1) is formed again in solstice. Accordingly, the full cycle of the wind evolution takes 24, 30, or 36 months depending on duration of the Stage 1. It is shown that stages with the disturbing winds (2, 4, 6, and 8) have maximum intensity around the equinox seasons. There is a definite connection between development of the disturbing winds and the temperature variations in layer of the maximal ozone content (20-30 hPa).