Analysis of precursors of tropical cyclogenesis during different phases of the solar cycle and their correlation with the Dst geomagnetic index

• Significant correlation between tropical cyclogenesis and the Dst geomagnetic index.
• Results suggest the existence of a 22-year periodicity in tropical cyclogenesis.
• Tropical cyclones might be modulated by geomagnetic activity influence in wind shear.

Three tropical cyclogenesis precursors, (absolute vorticity, relative humidity, vertical shear)and, the combined Genesis Potential Index are investigated in order to analyse their behaviour during three different phases(descending, minimum and ascending) of the solar cycle. The correlation between these tropical cyclogenesis precursors and the Dst geomagnetic index is also assessed, with the main finding being that the correlations between both the Genesis Potential Index and the vertical shear with the Dst index are statistically significant. This result suggests that the relationship between geomagnetic activity and tropical cyclones might be modulated by the influence of geomagnetic activity on the vertical wind shear.