The global signal of the 11-year sunspot cycle in the atmosphere: When do we need the QBO?

The global structure and the size of the signal of the 11-year sunspot cycle in the stratosphere and troposphere was examined in earlier studies. The correlations between the solar cycle and heights and temperatures of and at different pressure levels were mainly carried out with the whole data set and only during northern winters the years were separated according to the phase of the Quasi-Biennial Oscillation. Here, this work is expanded and it is shown that the Quasi-Biennial Oscillation must be introduced during northern summers, because the solar signal is very different in the respective phases of the Quasi-Biennial Oscillation, particularly over the tropics and subtropics. The structure of the solar signal in (northern) summer appears to indicate that the mean meridional circulations (Hadley and Brewer-Dobson Circulations) are influenced by the 11-year sunspot cycle, especially during the east phase of the Quasi-Biennial Oscillation. This result may help to find the mechanism through which the solar cycle (and the connected variation of the ultraviolet radiation) can influence the atmosphere.