Ominous warning about speed of hurricanes from scientists: they may have even more gunpowder in the future | Business

How close is Milton’s wind speed to the theoretical hurricane wind speed maximum? And is there a strict limit to it?

There is indeed a “speed limit” to wind speed, called the maximum possible intensity, but it is not absolute: it is determined by several factors, including the heat of the oceans. According to current estimates, the maximum possible intensity of storms usually reaches about 322 km/h.

But that could change in the coming decades as the oceans warm and the climate changes. Already, the potential for severe storms has been increasing over the past 30 years, notes Kerry Emanuel, professor emeritus of atmospheric sciences at MIT. So are raging storms: storms with wind speeds of over 309 km/h have been recorded five times. All of them originated from 2013.

“I think that by the end of the century, if we don’t take any measures, it will approach 354 km/h,” K. Emanuel told Live Science.

What causes a storm

The limit for hurricane-force winds is relatively easy to calculate, said climate scientist James Kossin of the National Oceanic and Atmospheric Administration (NOAA). He is a retired consultant for First Street, a climate risk modeling agency.

“The gunpowder of hurricanes is the heat they draw from the ocean,” Kossin said. “The warmer the water, the more gunpowder.”

After the 1962-1992 storm research found that only 20 percent Atlantic cyclones reach 80 percent. or more of its maximum possible intensity, although there is evidence that an increasing number of storms are beginning to approach the theoretical limit, said K. Emanuel.

As the oceans and atmosphere warm, storms intensify. in 2020 Mr. Kossinas and his colleagues reported that from 1979 to 2017 the share of major hurricanes increased by 8 percent over the decade. This means that strong and rapidly intensifying storms like Milton could become shockingly common as the climate warms.

Reuters/Scanpix photo/The worst hurricane Milton will hit the USA.

New hurricane categories?

Hurricanes are classified according to the Saffir-Simpson scale, which ranges from category 1 (wind speed – 119 km/h) to category 5 (252 km/h).

This scale is incomplete because it is based on wind speed and does not include storm surges or floods, which are more dangerous than wind and cause more damage, Emanuel said.

The increasing likelihood of severe storms led Kossin and his colleague Michael Wehner of Lawrence Berkeley National Laboratory to suggest in February that a category 6 on the Saffir-Simpson scale, which would include storms with winds above 308 km/h, might be needed.

The researchers identified five storms that already fit this category: Typhoon Haiyan (2013), Hurricane Patricia (2015), Typhoon Meranti (2016), Typhoon Goni (2020) and Typhoon Surigae (2021). . Patricia was the most intense hurricane and the only one with winds exceeding 200 km/h. (The hurricane had sustained winds of 345 km/h, but had weakened to 241 km/h by the time the storm made landfall.

M. Wehner and J. Kossin considered examining hurricanes in the theoretical category 7, with winds exceeding 368 km/h. However, their calculations showed that the risk of a storm of this magnitude is currently low, Wehner told Live Science, so they did not include that possibility in their work.

No one really knows what maximum winds a hurricane could theoretically sustain if water temperatures continue to rise, Wehner said.

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