LAUSR

This work aims to investigate the effect of solar-geomagnetic activities on atmospheric circulation and to examine their influences on global surface temperature (GST). Used data are the sunspot number (Rz) as a solar activity index, geomagnetic activity index (aa), the North Atlantic Oscillation index (NAO), and GST. We have performed an extensive analysis by using the wavelet power spectra (WPS) and global wavelet spectra (GWS). Results from WPS showed that both NAO and GST exhibited periodicities of ~ 22 years and 11 years, indicating the imprint of solar activity on both parameters. Additionally, the WPS of NAO exhibited three dominant modes; firstly, periodicity of 2 to 4 years appeared in the time intervals: (1954–1967), (1987–1997), and (2007–2015), possibly related to El-Nino Southern Oscillation. Secondly, sporadic oscillation of 1 to 2.5 years observed during the whole period, which corresponding to quasi-biennial oscillation. Finally, oscillatory modes with high power on the band 7 to 8.5 years are observed on NAO spectrum: 7.6 years for the period (1872–1892) and 8.3 years for 1996–2005. This oscillatory mode with enhanced power in the 8.3 years has been detected significantly on the GWS of GST, indicating the influence of climatic pattern on GST. Our results showed that the solar-geomagnetic activities influence partially and indirectly on GST through atmospheric circulation pattern.