• A $15 million machine at the University of Miami can simulate the conditions of a Category 5 hurricane.
• The acrylic tank — the largest of its kind — uses a wind tunnel and wave basin to mimic oceanic and atmospheric conditions.
• Brian Haus, the lab's director, told Business Insider that data from the tank could help forecasters better predict the paths and impacts of storms like Hurricane Dorian.
• His lab, for example, discovered that waves and sea spray can influence the severity of a hurricane. 
• Visit Business Insider's homepage for more.

Hurricane Dorian has been moving across the Atlantic Ocean for the last several days, but forecasters had some trouble predicting where it would make landfall and how much it would strengthen.

After making landfall in the Bahamas as a Category 5 storm on Sunday, the hurricane is now inching toward Florida's eastern coast.

Though hurricane models have improved over the last several decades, forecasters are still working to learn about how the storms form and intensify.

To answer these fundamental questions, they turn to data from places like University of Miami's Sustain Laboratory, where a $15 million machine can mimic the conditions of a Category 5 hurricane. 

Brian Haus, the director of the laboratory, told Business Insider how he's using the tank to help forecasters make better predictions about storms like Hurricane Dorian in the future. Here's what the hurricane tank looks like.

The storm simulations take place in an acrylic tank with a surface area of more than 4,200 square feet.

The tank is 75 feet long, 20 feet wide, and 6.5 feet deep, making it the world's largest hurricane simulator. 

The machine combines two devices: a wind tunnel that simulates a storm and a wave maker that mimics the open ocean.

Together, the wind tunnel and wave basin simulate random conditions that might prompt a storm. Sometimes the water might be choppy when the wind is mild. Other times the wind is erratic, while the waves are calm and steady. 

When the machine is turned on, a wind tunnel starts to pull in air from a giant fan, which generates a deafening whir.

The fan is motored by a 1,460-horsepower engine. In a matter of minutes, the air is spun around in chambers and unleashed into the tank at wind speeds of up to 157 miles per hour. The more the wind speed picks up, the louder the turbines become.

While the wind is entering the tank, 12 underwater paddles churn the 40,000 gallons of water below.

The paddles generate waves that crash against the sides of the tank and sea spray that flies through the air. 

Researchers are given headphones to muffle the sound as they study the interaction between the wind and waves.

Researchers peer through the glass tank to observe firsthand how a hurricane takes shape. 

Remote sensors on top of the tank help monitor the hurricane like a satellite, and lasers on the bottom show what's happening beneath the water. With these devices, the researchers can observe minute details that can't be measured during an actual storm, like the exact slope of a wave. 

The researchers also place model homes at one end of the tank to examine whether these structures can hold up under various storm-surge conditions. 

From there, they use computer models to determine patterns in hurricane behavior, from the direction of a storm to the way it builds.

Haus said his research focuses on two basic questions: How do hurricanes form, and how do they intensify? 

So his team examines conditions that might cause a hurricane to spin out, and works to determine how the heat coming off the ocean powers a storm.

"If you get a better understanding of how heat transfers to the ocean in different wind conditions, then you can get a better projection of how much more intense a storm can be," Haus said. 

Haus said climate change has generated a lot of "unresolved questions" for his lab.

Climate change is causing ocean water to become warmer later in the hurricane season, which can intensify hurricanes.

"It's pretty well understood that if the water is warmer and it's causing more moist air to come up, then you have the potential for a storm to grow quickly and intensely," Haus said. "The question is how much that's going to happen."

But he has also made a few significant discoveries, like the fact that waves and sea spray influence the severity of a hurricane.

The interaction between the wind and the ocean surface's creates friction. Scientists used to think that friction rose along with wind speed, but Haus' lab discovered that friction is also affected by ocean waves and sea spray. 

If waves crash against land in shallow water, he said, they might produce less friction, which could allow a hurricane to speed up. In deep ocean water, he said, there's nothing to obstruct the waves, so they may weaken a storm. At the same time, sea spray may also transfer heat from the ocean, thereby speeding up winds.

Though the wind speed determines the category of a hurricane, Haus said people should focus less on categories and more how things like storm surge interact with land.

"A Category 1 storm approaching a particular coastline in a particular way can produce really dangerous conditions and storm surges that aren't encapsulated by the simple wind speed," he said.  

Haus firmly opposes President Donald Trump's suggestion to drop nuclear bombs into hurricanes. "I've heard a lot of ideas put forth about how to disrupt a hurricane, but none as ludicrous nuking them," he said.

But he added that "people might be surprised to know" that the technology used to measure hurricanes doesn't necessarily get better every year.

He said the US needs to continue to invest in satellites, remote sensors, and direct observations of the ocean to monitor and predict hurricane behavior. 

As for whether we'll ever be able to intervene to weaken a hurricane in other ways (without nukes), Haus said such proposals often raise ethical problems. Decades ago, he said, the National Oceanic and Atmospheric Administration (NOAA) tried to experiment with ways to weaken or redirect hurricanes, but that came with major risks: "If that storm ended up hitting somebody, you were monkeying with that storm and you caused it to do that," Haus said. 

You can explore the lab for yourself in this 360-degree panorama.

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