Reaction of the North Atlantic Oscillation to intense geomagnetic storms

GERARDO L. FLORES IVALDI; ANA G. ELIAS; MARTA ZOSSI DE ARTIGAS; TERESITA HEREDIA

Cusco

Congreso; X COLAGE; 2014

ALAGE

The possible link between the North Atlantic Oscillation (NAO) and intense geomagnetic storms is analyzed in the present work. Several studies have already shown a significant positive correlation between long-term variations in the NAO and geomagnetic activity suggesting a plausible link between them. However, at daily timescales we observe a decrease in the NAO index coincident with the maximum intensity of the geomagnetic storm measured through the aa index. A physical process is proposed to explain this result in the context of an overall increasing trend which may be due to anthropogenic activity.