Statistical link between united states tropical cyclone activity and the solar cycle

Abstract

The recent increase in the power of Atlantic tropical cyclones is attributable to greater oceanic warmth in part due to anthropogenic increases in radiation from greenhouse gases. However solar activity may directly influence a hurricane's power as well. In this chapter we report on a finding that Caribbean tropical cyclone activity and U.S. hurricane counts have a pronounced 10-year periodicity with tropical cyclone intensities inversely correlated with sunspot number on the inter-annual and daily time scales. The finding is in accord with the heat-engine theory of hurricanes that predicts a reduction in the maximum potential intensity with a warming in the layer above the hurricane. An active sun warms the lower stratosphere through ozone absorption of additional ultraviolet (UV) radiation. Since the dissipation of the hurricane's energy occurs through ocean mixing and atmospheric transport, tropical cyclones can act to amplify the effect of a relatively small change in the sun's output appreciably altering the climate. The finding has serious implications for life and property throughout the Caribbean, Mexico, and portions of the United States. © 2009 Springer-Verlag US.