Meteorologist: Dust cloud makes spectacular sunrises, sunsets
Dust can also keep hurricanes from forming
Meteorologist Jim Lushine
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(CNN) -- An enormous cloud of dust is blowing toward the United States from the Sahara Desert in Africa, potentially creating spectacular sunrises and sunsets in Florida.
CNN's Miles O'Brien discussed the phenomenon Monday with Jim Lushine, a severe weather expert with the National Weather Service in Miami, Florida.
O'BRIEN: Jim, you're about 39 days away from retirement, right?
LUSHINE: That's it. I'm getting close now.
O'BRIEN: So you've had a long, illustrious career there. How frequently do you have to talk about dust clouds coming from the Sahara to Florida?
LUSHINE: We've been seeing them now for about 35 years actually looking at satellite pictures. And they're not that uncommon. They occur a half a dozen, a dozen times a year.
This one is actually a fairly large one and significant one, and we're actually seeing some effects here even this morning.
O'BRIEN: Tell us about the effects then.
LUSHINE: Well, mainly it does to the optics; that is, it makes the sunrises, sunsets a little more spectacular. There is some haze in the air, not dissimilar really to what you get on a normal day, say, in New York City with the pollution and so on like that. But it's a little bit unusual here in south Florida, where we have more blue skies.
O'BRIEN: This is one of the hidden advantages of pollution, we get a better sunset?
LUSHINE: That's actually true. You do get more reds and yellows.
O'BRIEN: All right. Keep those SUVs going, I guess, huh?
LUSHINE: Yes, that's it.
O'BRIEN: So this is actually good Chamber of Commerce weather then?
LUSHINE: Well, in some ways, yes. Of course, it actually helps keep away some of the thunderstorms and also has some other impacts on the weather itself.
O'BRIEN: Tell us about that.
LUSHINE: It actually inhibits the development of hurricanes, which of course, we've had too many of this year already. And so when we get the dust out there, that stabilizes the atmosphere in such a way that it doesn't really allow the thunderstorms to build up and that keeps the hurricane activity down a little bit.
O'BRIEN: So the dust actually thwarts the build-up of clouds which makes thunderstorms?
LUSHINE: Right. That's it. The stability is one of the ingredients of making thunderstorms. When you have very stable air, like you have with the Saharan dust, that keeps the thunderstorms from building up. That keeps the hurricanes from forming.
O'BRIEN: All right, we've got some satellite imagery, which comes from some of the NASA and NOAA satellites that are looking for these things. What causes it initially? What are the root causes? Is it a certain wind pattern which develops over the Sahara that causes this?
LUSHINE: Yes, it's a tropical wave, which is like the seedling for hurricanes, and this tropical wave creates some winds of 30 to 40 miles an hour, that create a dust storm, and we're talking about a large area, like about 300 miles in length.
So when that dust then gets trapped up in the air, it comes east on the trade winds, and then it comes all the way across the ocean, about 3,500 miles, takes about 10 days to get here.
O'BRIEN: And does it just keep going, or does it settle out in Florida? What happens after Florida?
LUSHINE: It generally settles out, but it does move a little farther west. Sometimes Texas can get it, sometimes other parts in the southeast United States. It doesn't usually get as far north as the northeast United States. As I mentioned, the pollution up there, you probably wouldn't notice much difference in it anyway.
O'BRIEN: All right, and we've been talking about sort of the upside, those nice sunsets. A couple of downsides. Coral reefs are adversely impacted, and some folks might with respiratory problems, might have some problems as well, right?
LUSHINE: Yes, there is a little bit of increase in the particulate matter, so that the air-quality index may be raised just a little bit, but in general, it's not a big affect on people.
O'BRIEN: OK, and then the coral reefs are going to OK? Is that a huge problem for them?
LUSHINE: It's not an instantaneous kind of thing. It goes on over years and years, where the pathogens in the dust itself actually cause some problems with the coral reefs. But you know, it's not something that just happens at one particular time.
O'BRIEN: All right, Jim Lushine, we wish you a good retirement. Jeez, if you're from Miami, where do you retire to, Cleveland? Where do you go?
LUSHINE: I'm going to Alaska.
O'BRIEN: You're going to Alaska. All right.
O'BRIEN: Enjoy the retirement.
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