Longer and Stronger Hurricanes Caused By Warmer Sea Surface

Researchers from the Okinawa Institute of Science and Technology (OIST) conducted a study to find ways countries can manage the effects of climate change. The study revealed that as a result of warmer temperatures, hurricanes become stronger, and last longer before they weaken.

In analyzing their findings, the researchers from the Graduate University of OIST discovered that the warmer the ocean water becomes, the greater the amount of moisture carried by the hurricanes. As results, the weather disturbance increases in strength, while staying longer in the atmosphere before making a landfall. When combined with a corresponding increase in the Earth’s temperature, hurricanes become more devastating.

According to Pinaki Chakraborty, the senior author and head of the Fluid Mechanics Unit at OIST, taking into account the implications found by the researchers are important in creating policies aimed at managing global warming. Also, in light of their findings, Professor Chakraborty added that inland communities should be advised to prepare for hurricanes that will bring heavy rainfall and intense winds.

The OIST Graduate University scientists said that while numerous studies have already proven climate change has been causing hurricanes to worsen, this latest research has proven that certain underlying factors that take place upon landfall are making hurricanes stronger and more devastating.

How the Researchers Proved their Discovery

In conducting their study, the OIST researchers analyzed the North Atlantic hurricanes that have hit the land for the last 50 years and from there discovered that recent hurricanes weakened at a slow pace, when compared to those that made landfall in the past.

According to Lin Li, a PhD student at OIST and the first author of the study, they found out that the amount of time it took for a hurricane to weaken was in consonance with the rise and fall of temperature of the sea surface. To prove their discovery, the research scientists simulated a landfall occurrence by decreasing the hurricane’s supply of moisture once it reached category 4.

To illustrate by way of example, Li compared hurricanes to car engines, to which moisture serves as the hurricane’s fuel. If the sea surface temperature increases, the occurrence removes the source of moisture fueling the hurricane, and as a result the lack of moisture will weaken the hurricane.

After simulating hurricanes by creating landfall models with the same intensity as the hurricanes that developed on warmer waters, the hurricanes showed longer durations. They also discovered why hurricanes are still intense even without the supply of moisture from the ocean surface. It became apparent that the reason was that the hurricanes carry a considerable reserve of moisture- supply, which allow them to continue even without the supply coming from the ocean.

To complete their analysis, the researchers created simulated hurricanes with no stored moisture after landfall, from which they learned that the temperature of the water surface does not affect the duration of the hurricanes.