Until now, it was believed that hurricanes are maintained by the ocean alone. Observations from 62 hurricanes during 32 years support a different, nuanced conclusion. Besides the ocean, near-surface air temperature and moisture play a large, often dominant, role in maintaining a hurricane.
1. The long-held belief that an ocean surface temperature of at least 26 degrees C (80 degrees F) is required to maintain a hurricane was not supported in 6% of the cases studied. Atmospheric moisture conditions in areas of high wind speeds are what cause the “80-degree F threshold” for hurricanes.
2. For hurricanes within 29 degrees of the equator, the atmosphere, not the ocean, was found to be the most important factor in maintaining the hurricane.
The full paper can be accessed at http://journals.ametsoc.org/doi/abs/10.1175/MWR-D-13-00380.1.