Sunspots, the QBO, and the Stratosphere in the North Polar Region: An Update

The 11-year sunspot cycle (SSC) strongly affects the lower stratosphere. However, in order to detect the solar signal it is necessary to group the data according to the phase of the Quasi-Biennial Oscillation (QBO). Although this is valid throughout the year the effect of the SSC and the QBO on the stratosphere was largest during the northern winters (January/February). As the stratosphere can affect weather at the ground, the SSC effect on the lower stratosphere might provide a mechanism for solar-climate links. Here we analyse an extended, 65-year long data set of solar variability, QBO, and lower stratospheric dynamics. The results fully confirm earlier findings and suggest a significant effect of the SSC on the strength of the stratospheric polar vortex and on the mean meridional circulation.