When he turned up for his first flight into a hurricane in 1997, had fair warning about what he was getting into. His boss, he says, was known as a 鈥渟even-bagger鈥� 鈥� someone who had filled up seven air-sickness bags on one flight. Dunion is a meteorologist with the US National Oceanic and Atmospheric Administration (NOAA), based in Miami, Florida. He鈥檚 one of a handful of scientists who carry out research flights that cut through the Atlantic鈥檚 mightiest storms.
This year, the has witnessed some of the strongest hurricanes on record in what has proved to be an extraordinarily busy season. He flew into Hurricane Irma, a category five storm, as it wreaked havoc in the Caribbean.
How does it feel to fly into a hurricane?
It鈥檚 like a rollercoaster except you don鈥檛 know when that big drop or rise is going to happen. You鈥檙e trying to concentrate on instruments while you鈥檙e hitting these intense up- and downdrafts. You can lose or gain hundreds of feet of altitude in an instant.
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I鈥檝e seen some really dramatic drafts where I suddenly experienced zero gravity 鈥� I鈥檓 floating and so are the things around me. That鈥檚 pretty intense. But then you pop out into the eye 鈥� the calmest part of the storm, and that鈥檚 like flying on American Airlines.
Why do you need to get so close to a monster storm?
Our job is to figure out what makes hurricanes tick. Why do they get so strong? Why do they weaken? Why do they go where they go? We take out the aircraft and try to answer these questions. We鈥檝e got two aircraft, two NOAA P3s, which are rugged planes 鈥� they fly right into the eye. Then we鈥檝e got a jet that typically flies around the outskirts of the storm taking readings.
So was Hurricane Irma a bumpy ride?
I鈥檇 never flown into a category five storm before Irma. They are rare beasts: the conditions have to be perfect. The sea surface temperatures have to be warm, the environment moist, the winds just right. Irma lasted for over three days as a category five. By our records, that鈥檚 only happened twice, and it hasn鈥檛 happened for more than 35 years.
We had a night flight, so we were taking off about 3am and we were watching the satellite picture. The cloud tops were bubbling and brewing 鈥� it was clearly strengthening pretty quickly. I looked over at one of my friends who was also flying and said, this is going to be an intense flight. We ended up having flight-level winds exceeding 240 kilometres per hour 鈥� the plane was flying right through that.
What stood out on that flight?
Around the eye of a storm is a wall of cloud and its most powerful winds. When we flew in, Irma had an inner eyewall, but there was a new one forming outside it. Every time we flew through the storm, that outer eyewall became better and better defined and the inner one just eroded away. Really powerful storms go through these cycles. They could affect forecasting because suddenly you have this eyewall that鈥檚 much further out from the centre, and this has a direct bearing on how strong the storm is, and the width of its powerful wind field. That鈥檚 especially important if the storm is going to be making landfall, because a wider wind field does more damage. We were in the storm for 5 hours and we watched that whole process take place. I think this hurricane season will lead to some big advancements in understanding these cycles. Hurricane Maria is going through the process as I speak.
Did Irma cause problems for your colleagues on the ground in Florida?
One of the things that struck me with Irma was that the hunters became the hunted. We not only had to make our flights happen and get that data collected and sent out to the modelling centre and the hurricane centre, but at the same time folks had to batten down the hatches, get their houses prepared and protect their families.
Have your methods improved since you started flying?
We now use parachuted weather sensors called that we drop into the eyewall. We even have a microwave sensor now that looks at the ocean and can tell how strong the winds are that are roiling that ocean surface. That really changed forecasting. And we鈥檝e recently added the Doppler radar on the tail of the plane. It can give us a 3D wind field almost down to the ocean surface from the very top of the storm.
And this year we are trying out a high-altitude drone called the . It鈥檚 got a 40-metre wingspan. It鈥檚 a huge aircraft that flies at 60,000 to 65,000 ft. That aircraft is able to give us measurements that we usually can鈥檛 get because it can fly for 24 hours at a time around storms and because it flies so high 鈥� right over the top of most of these cyclones.
