New approach to improve hurricane intensity forecast

New York, July 11 (IANS) In what could offer a new method to aid in storm intensity prediction of hurricanes, researchers have found that physical conditions at the air-sea interface, where the ocean and atmosphere meet, is a key component to improve forecast models.

"The general assumption has been that the large density difference between the ocean and atmosphere makes that interface too stable to effect storm intensity," said Brian Haus, professor of ocean sciences at University of Miami in the US.

"In this study we show that a type of instability may help explain rapid intensification of some tropical storms," Haus added.

The research team's experimental simulations show that the type of instability, known as Kelvin-Helmoltz instability, could explain this intensification.

Experiments conducted at University of Miami Rosenstiel School Air-Sea Interaction Salt Water Tank (ASIST) simulated the wind speed and ocean surface conditions of a tropical storm.

The researchers used a technique called "shadow imaging", where a guided laser is sent through air and water to measure the physical properties of the ocean's surface during extreme winds, equivalent to a category-3 hurricane.

Using the data obtained from the laboratory experiments, the researchers then developed numerical simulations to show that changes in the physical stress at the ocean surface at hurricane force wind speeds may explain the rapid intensification of some tropical storms.

The study appeared in the journal Nature Scientific Reports.