Aaron Schachter: Typhoons are tropical cyclones, just like hurricanes. They just happen to be in the Pacific rather than the Atlantic. But despite being similar in nature, the storms are studied in different ways, so says Kerry Emanuel, a professor of atmospheric science at MIT.
Kerry Emanuel: Part of the problem in the western Pacific is we're not actually measuring typhoons very well. We did fly aircraft into them in the period up to 1987, and we made quite good measurements of their intensity in those days. But today, we rely on satellites, which are very good for detecting the presence of typhoons, but not all that great in measuring their strength.
Schachter: How powerful was this one, do we know?
Emanuel: Well, we don't know, and unfortunately in all probability we'll never know. I do know that some of the analysts who are used to working with Pacific typhoons, when they looked at the images of this latest one, have said that it had the most violent satellite presentation that they recall seeing.
Schachter: What made this particular storm so deadly?
Emanuel: Most of it is because the storm happened to reach peak intensity just about the time it made landfall. You know, storms have life cycles and it's really a coincidence if they happen to reach their peak right when they strike a populated area. Most storms, there are a lot of Cat 5s out in the western Pacific, some of them never hit land at all and some of them have wound down considerably, or haven't intensified up to their peak by the time they hit land. This is just a really bad luck, is what we have to ascribe this to.
Schachter: And how does it... you mentioned it's a Cat 5 storm. How does this compare to Super storm Sandy, which hit the east coast, here in the US, last year?
Emanuel: Well, it's a great comparison. So Sandy was, by some measures, not even a Cat 1 or at most a Cat 1 hurricane, and yet it did all this destruction. What this illustrates more than anything else, and I think this is an incredibly important messages, is that there is no single number, there is no scale that you can event, that really conveys the risk. There is a reason that we give these storms names, and that is they all have their individual characteristics, like snowflakes. So Sandy, although it wasn't very strong in terms of peak winds, was slow moving and enormous in diameter. And we all knew that it was going to cause a really big storm surge in New Jersey and New York, and it did. In the case of this latest typhoon in the Philippines, you had also a large storm, not perhaps as large as Sandy, but really, really high winds in the core. Lots and lots of rain from this, and it also created a big surge because of the intensity of the winds.
Schachter: So Kerry, here's the big question. There's a lot of speculation whenever there's a big storm these days. Did climate change play a role?
Emanuel: Well, certainly it played a role with one obvious respect, is that sea levels elevated. And so the storm surge, which is a big killer, and causes a lot of destruction both in the case of Sandy, and the case of this most recent storm was higher than it would have been. Beyond that, though, it's difficult and perhaps impossible to attribute one particular event to any kind of climate signal, whether it's global warming or El NiÃ±o or some other phenomenon.
Schachter: Kerry Emanuel is a professor of atmospheric science at MIT. Kerry, thank you so much.
Emanuel: You're quite welcome.