Connection between the solar cycle and the QBO: The missing link

Evidence of the solar cycle in stratospheric polar temperature rests on a c onnection to the quasi-biennial oscillation (QBO) of equatorial wind. New e vidence reported here establishes a mechanism for how the solar signature i n polar temperature follows from the QBO, which itself is shown to vary wit h the solar cycle. Equatorial westerlies below 30 mb vary systematically wi th solar activity, as do equatorial easterlies above 30 mb. Changes in thei r duration introduce a systematic drift into the QBO's phase relative to wi nter months, when the polar vortex is sensitive to equatorial wind. Corresp onding changes in the polar-night vortex are consistent with the solar sign ature observed in wintertime records of polar temperature that have been st ratified according to the QBO.