Origin of Hurricanes
by: Laurie Johnson, July 27, 2006 12:07:00 am
Most hurricane studies are done on the west side of the Atlantic, basically the eastern seaboard of the United States. But NOAA Hurricane Researcher Jason Dunion says a significant number tropical waves form off the coast of Africa and this will be the first major effort to understand how hurricanes originate from those swirling thunderstorms.
"And about one in ten of those forms into some kind of named storm, whether it's a tropical storm or a hurricane. And they account for about 85 percent of the major hurricanes that we see in the Atlantic, so you could almost think of it as a breeding ground for a lot of the hurricanes that may eventually impact the United States, a storm like, say, Katrina."
The area in question is around the Cape Verde Islands, about 350 miles off the coast of Senegal in West Africa. The interesting thing about this area is while many hurricanes form here, it's also a spot where Saharan dust storms create a sort of hurricane blocker. Dunion says NOAA and NASA are trying to figure out how so many storms develop despite the dust formations.
"How do they impact the hurricanes? What are the mechanisms, what are the interactions that happen that can either weaken a storm, or sometimes we see storms that pull out of these layers can actually intensify very rapidly. So that's another key area of research interest for us. How does the dust that's in these Saharan air layers, this is just desert dust that gets swept up into the atmosphere, does that dust actually affect the hurricane?"
Two teams will send planes into these storm formations. NASA is sending 50-70 scientists and technicians out with a DC8 research plane. NOAA will have a couple of smaller teams in the Caribbean with a P3 Hurricane Hunter which goes right into the eye of a hurricane and a high-altitude jet. Dunion says this is the most expansive aircraft coverage of hurricanes ever done.
"The ultimate goal here is to improve our forecasts of tropical cycle intensity and track, especially intensity which we need to make some advancements in. You know, the National Hurricane Center has the job of forecasting hurricanes out to five days. And I could see at some point down the road, it might be many years down the road, that could be extended beyond five days. It might be up to ten days in ten or 20 years. So the job for us as researchers is to try to pave the way to the understanding so that the forecasts that the Hurricane Center makes are as good as we can get them."
The scientists will monitor these storms from mid-August through mid-September when hurricane conditions should be most favorable. Hurricanes develop in places where there are warm ocean waters, moist, humid air and spiraling winds. Laurie Johnson, Houston Public Radio News.