The years 1995 to 2000 saw more hurricane activity in the North Atlantic than any five-year period on record. Unfortunately, it looks like this wasn't just a blip on the radar. It could have been just the beginning of a trend that could last for decades.
A bull market for hurricanes. I'm Bob Hirshon and this is Science Update.
After a couple of sleepy decades, hurricanes are making a strong comeback. That's according to Stanley Goldenberg, a meteorologist at the National Oceanographic and Atmospheric Administration. He explains that hurricanes cycle through long periods of high and low activity. And it looks like we're back in a rough patch.
In other words, it just switched very strongly in 1995. We won't expect it to switch back anytime soon. Therefore this higher level of activity could stay around for another ten years or even up to 30 or 40 years.
He says the changes come from natural fluctuations in sea surface temperatures and wind shear patterns. Central America and the Caribbean have already been hit with devastating storms, like Hurricane Mitch in 1998. And Dr. Goldenberg says the United States could soon become more vulnerable.
Up till now there's been a persistent steering pattern—we call it a trough sitting off the East Coast of the United States during most of these seasons—steering a lot of the storms out to sea. It's only a matter of time, we feel, until that shifts, and that would allow more storms to start impacting Florida and the East Coast, and that impact might be rather dramatic.
He says emergency plans may need a second look to make sure they're adequate. For the American Association for the Advancement of Science, I'm Bob Hirshon.
Making Sense of the Research
Hurricanes occur as part of a natural cycle resulting from fluctuations in sea surface temperatures and wind shear patterns. Research suggests that very long term climate shifts may be changing that cycle, causing increased hurricane activity in the Caribbean and areas of the United States, such as Florida and the East Coast. While the actual number of hurricanes may not increase, it is expected that their impact and reach will—a change that will require a critical evaluation of the United States' emergency preparedness.
Now try to answer these questions:
- In about what year did the hurricane pattern switch from low activity to high activity?
- How long might high activity stay with us?
- According to Stanley Goldenberg, what causes these changes in hurricane activity?
- In the future, why might we see more hurricanes impacting Florida and the East Coast?
- What type of actions do you think people living on the East Coast and in Florida could take now to prepare for any future hurricanes that come ashore?
For easy-to-read information on how hurricanes work and what they do, go to NASA sponsored Tropical Twisters or USA Today's Hurricanes feature.
To track current hurricane activity and to learn about hurricane awareness and safety, check out the National Hurricane Center Tropical Prediction Center, a National Oceanic & Atmospheric Administration sponsored project.