Research in Engineering and Aviation

In Search of Links Between Terrestrial Hurricanes and Drifting Ice Giant Vortices

2013

Author(s): R.P. LeBeau and Cs. Palotai

In Search of Links Between Terrestrial Hurricanes and Drifting Ice Giant Vortices. Accepted to the 5th AIAA Atmospheric and Space Environments Conference, San Diego, CA. 

Abstract

The recent natural disasters associated with hurricane Sandy are but one example of the dangers presented by hurricanes and typhoons. Predicting the track of these features remains a significant meteorological challenge, with predictive models often diverging significantly within a couple of days. The difficulty of hurricane prediction is in part due to the number of factors influencing their movement, including ocean temperature and currents, land masses, broader weather patterns, the jet stream, cloud microphysics, and the coriolis effect. All of these factors help mask the underlying mechanisms driving hurricane drift and thereby limiting our understanding of these phenomena. However, terrestrial hurricanes are not the only example of coherent, drifting atmospheric vortices.  The first Great Dark Spot, a geophysical vortex discovered by Voyager II in 1989, drifted about 10 degrees in latitude over eight months of direct observation. In 2005, a long lived cloud feature on Uranus called the “Berg” suddenly began to drift towards the equator at a rate of several degrees per year, an event possibly linked to a hidden vortex beneath the clouds. These systems, with no land or oceans and simpler background weather patterns, may provide a more straightforward analysis of vortex drift than terrestrial features, yet share fundamental mechanisms that drive the motion. Improvements to a current General Circulation Model used to analyze the Ice Giant atmospheres now allow a more detailed investigation of these drifting vortices and the possible links between their motions and those of hurricanes.