The Role of the Solar Cycle in the Relationship Between the North Atlantic Oscillation and Northern Hemisphere Surface Temperatures

The North Atlantic Oscillation (NAO) is one of the leading modes of climate variability in the NorthernHemisphere. It has been shown that it clearly relates to changes in meteorological variables, such as surface temperature,at hemispherical scales. However, recent studies have revealed that the NAO spatial pattern also depends upon solarforcing. Therefore, its effects on meteorological variables must vary depending upon this factor. Moreover, it could bethat the Sun affects climate through variability patterns, a hypothesis that is the focus of this study. We find that therelationship between the NAO/AO and hemispheric temperature varies depending upon solar activity. The results show apositive significant correlation only when solar activity is high. Also, the results support the idea that solar activityinfluences tropospheric climate fluctuations in the Northern Hemisphere via the fluctuations of the stratospheric polarvortex.