Cloud anomalies at midlatitudes of the Northern and Southern Hemispheres: Connection with atmospheric dynamics and variations in cosmic rays

Long-term correlations between the state of low clouds and variations in the flux of galactic cosmic rays (GCRs) were studied. It has been shown that the links between low cloud anomalies and GCR fluxes at midlatitudes of the Northern and Southern Hemispheres are caused by variations in the extratropical cyclogenesis intensity which correlated with changes of GCR fluxes in the period from the early 1980s to 2000. At the beginning of the 2000s, the correlation between cloudiness and variations of GCR fluxes was violated, a possible reason being a sharp weakening of the stratospheric polar vortices in the Northern and Southern Hemispheres, which resulted in the change of GCR contribution to the circulation of the lower atmosphere.