Sushmita Pathak

So the starting point of the research was really like the geographic setup in Central North America and Central South America is kind of similar. But South America does not get as many tornadoes, even near as many tornadoes as North America does. And so... they really wanted to figure out why there was this huge contrast.

And what they found was it was because of a surprising new ingredient, which is the roughness of the land surface many, many thousands of kilometers away from where the tornadoes were actually happening. So when the easterly winds are coming over the Gulf of Mexico towards central North America, Tornado Alley, that's a relatively smooth surface, this vast expanse of ocean.

And what they found was it was because of a surprising new ingredient, which is the roughness of the land surface many, many thousands of kilometers away from where the tornadoes were actually happening. So when the easterly winds are coming over the Gulf of Mexico towards central North America, Tornado Alley, that's a relatively smooth surface, this vast expanse of ocean.

And what they found was it was because of a surprising new ingredient, which is the roughness of the land surface many, many thousands of kilometers away from where the tornadoes were actually happening. So when the easterly winds are coming over the Gulf of Mexico towards central North America, Tornado Alley, that's a relatively smooth surface, this vast expanse of ocean.

So winds don't really encounter any resistance. They can build up a lot of speed. And that's really important for wind shear, which is very important for tornado formation. But in South America, what happens is those easterly winds are blowing over the Amazon rainforest. So you have a lot of vegetation, a lot of hills, so a very rough surface.

So winds don't really encounter any resistance. They can build up a lot of speed. And that's really important for wind shear, which is very important for tornado formation. But in South America, what happens is those easterly winds are blowing over the Amazon rainforest. So you have a lot of vegetation, a lot of hills, so a very rough surface.

So winds don't really encounter any resistance. They can build up a lot of speed. And that's really important for wind shear, which is very important for tornado formation. But in South America, what happens is those easterly winds are blowing over the Amazon rainforest. So you have a lot of vegetation, a lot of hills, so a very rough surface.

And because of this rough surface, the winds get broken down. And so the tornado potential also gets suppressed.

And because of this rough surface, the winds get broken down. And so the tornado potential also gets suppressed.

And because of this rough surface, the winds get broken down. And so the tornado potential also gets suppressed.

Just the region near the equator from where the easterly winds are coming into those regions.

Just the region near the equator from where the easterly winds are coming into those regions.

Just the region near the equator from where the easterly winds are coming into those regions.

And to test this sort of hypothesis and to arrive at their findings, the researchers tested this out in a global climate model, which is like a computer simulation of the Earth. Scientists use it all the time to learn about climate patterns and figure out how they'll change in the future. So in this global climate model, you can sort of tweak different parameters to see how things will change.

And to test this sort of hypothesis and to arrive at their findings, the researchers tested this out in a global climate model, which is like a computer simulation of the Earth. Scientists use it all the time to learn about climate patterns and figure out how they'll change in the future. So in this global climate model, you can sort of tweak different parameters to see how things will change.

And to test this sort of hypothesis and to arrive at their findings, the researchers tested this out in a global climate model, which is like a computer simulation of the Earth. Scientists use it all the time to learn about climate patterns and figure out how they'll change in the future. So in this global climate model, you can sort of tweak different parameters to see how things will change.

And so what the scientists did was they replaced the Gulf of Mexico with forests to make it kind of rougher. And when they did that, they saw that tornado potential in the US, in Tornado Alley, it went down. Wow. And similarly, when they smoothed out the Amazon forest, tornado potential in Central South America went up.

And so what the scientists did was they replaced the Gulf of Mexico with forests to make it kind of rougher. And when they did that, they saw that tornado potential in the US, in Tornado Alley, it went down. Wow. And similarly, when they smoothed out the Amazon forest, tornado potential in Central South America went up.

And so what the scientists did was they replaced the Gulf of Mexico with forests to make it kind of rougher. And when they did that, they saw that tornado potential in the US, in Tornado Alley, it went down. Wow. And similarly, when they smoothed out the Amazon forest, tornado potential in Central South America went up.

And I say tornado potential here because the model cannot produce tornadoes exactly. It can only simulate the environment, the instabilities that lead to a tornado. So that's just a small but important caveat.