TORNADOES: Forces of Nature or New Extreme Weather Patterns From CLIMATE CHANGE?

What factors contribute to
 extreme weather?

While many environmental groups have been warning about extreme weather conditions for a few years, the World Meteorological Organization announced in July 2003 that “Recent scientific assessments indicate that, as the global temperatures continue to warm due to climate change, the number and intensity of extreme events might increase.”

Of course global warming should lead to more—and more powerful—tornadoes.

We’re adding energy to the atmosphere by trapping heat with greenhouse gases, and tornadoes are the very picture of terrifying atmospheric energy.

Linking any particular weather event to climate change is always tricky, because weather is inherently random. But weather patterns can speak to a warming planet. Scientists can detect that extreme rain events, for instance, are already happening more often than they used to, and that a warmer atmosphere with more water vapor in it is making such events more likely.

Tornadoes are different. Global warming may well end up making them more frequent or intense, as our intuition would tell us. Since we’re changing the climate, the historical record is no more certain a guide to the future than intuition is. So what does physics tell us about the future of tornadoes in a CO2-warmed world?

“It really comes down to two ingredients in the atmosphere, in the environment in which storms form,” says Jeff Trapp, an atmospheric scientist at Purdue University.

Trapp has been on the road in Kansas and Oklahoma since last week, launching weather balloons into supercells—large, tornado-producing thunderstorms—as part of an effort to improve forecasting. He was 20 or 30 miles away from Moore when the tornado hit on Monday.

The first ingredient needed to make a tornado, he explains, is energy in the form of warm, moist, unstable air. In Oklahoma, that comes on southerly winds off the Gulf of Mexico.

The second ingredient is wind shear—a measure of how much the wind changes speed and direction between the ground and higher levels of the atmosphere. “Essentially that’s determined by the strength of the jet stream,” which blows in from the west, says Trapp. Wind shear causes the warm, rising air inside a supercell to start rotating, a necessary condition for organizing the storm and allowing it to spawn funnel clouds.

And that gets at the nub of the question surrounding a potential nexus between warming and tornadoes: Although climate change is increasing the energy in the atmosphere.

That’s because the jet stream is powered ultimately by the temperature difference between Earth’s hot tropics and its cold poles, and that difference is decreasing with climate change, as the poles warm faster than the rest of the planet. Say: National Geographic.

Low gray clouds loom in the distance. Suddenly, a tail descends from one of them, and twists itself into a spinning, funnel-shaped system – a tornado. It whips back and forth as it moves across the earth, churning away houses, trees, and other objects with the tremendous force of its spinning winds.

A tornado is a powerful column of winds spiraling around a center of low atmospheric pressure. It looks like a large black funnel hanging down from a storm cloud. The narrow end will move over the earth, whipping back and forth like a tail.

The winds inside a tornado spiral upward and inward with a lot of speed and power. It crates an internal vacuum that then sucks up anything it passes over. When the funnel touches a structure, the fierce winds have the ability to tear it apart.

The winds inside a twister can spin around at speeds up to 500 miles an hour. This makes the tornado the most dangerous storm known to mankind. Because of the earth’s unique weather system, twisters rotate counterclockwise in the Northern Hemisphere and move eastward. They rotate clockwise in the Southern Hemisphere. Tornadoes also often come with hailstorms.

Many storms create harmless funnels that never touch earth. They can last from a few seconds to a few hours. Others disappear and reappear minutes later. The average tornado has a diameter of about 200 to 300 yards, and some grow large enough to spawn smaller tornadoes known as satellite tornadoes. These small offspring, about 50 yards across, can be very fierce and do lots of damage. They also tend to branch away from the parent funnel, taking separate paths across the earth.

A tornado can form very quickly, sometimes in a minute or less. It can travel across the ground at high speeds, and then just as suddenly vanish. They can kill in a matter of seconds. Every year, twisters in the United States do about $500 million worth in damage. Most tornadoes last less than twenty minutes and travel less than 15 miles. However, superstorms sometimes occur, traveling over 100 miles before they are exhausted. Although they don’t occur very often, they are responsible for 20% of all tornado casualties.

So what causes these ferocious spinning wind machines and why don’t we see more of them here in the northeast? Let me explore the answer to both of these questions.

Tornadoes form as part of a thunderstorm. Only a thunderstorm has strong enough meteorological dynamics to produce a true tornado. That said, there are other tornado-like phenomena that can occur in the absence of a thunderstorm. Cold air funnels and dust devils are two such examples. You probably have seen leaves whirling around in a parking lot on a sunny day in something that looked like a mini tornado. Those are dust devils. They develop over hot surfaces, like a parking lot or the desert, and can sometimes reach wind speeds similar to a weak tornado. Cold air funnels are a bit more meteorologically complicated, but basically occur when unusually cold air becomes part of a large dying low-pressure area. They are very short-lived, weak and don’t often hit the ground.

Another very dangerous and real tornado like phenomena is a “fire whirl”. These nasty things occur in forest fires when the hot air begins to rise and circulate. Basically, you have a tornado of fire, not something I want to experience.

What we are seeing on the news the past several days are more typical tornadoes that come from very large thunderstorms called supercells. These storms actually rotate. I am not referring to the tornado, but the thunderstorm itself that actually has its own rotation.

The reason the storms rotate is that the winds are relatively weak and the ground and much stronger in the middle of the thunderstorm. Picture a pipe lying horizontally just above the ground. If you moved air faster over the top of the pipe than you had at the base, the pipe would start to spin. Now that spinning would be parallel to the ground.

In a thunderstorm the warm air is raising so fast, it picks up that rotation and moves it so it’s perpendicular to the ground. You can see the progression of this process in the image below.

The reason some supercell thunderstorms produce tornadoes and others don’t isn’t fully understood. Research suggests the rotation air is squeezed at the ground and then pulled up into the air. The squeezing is similar to a skater pulling in their arms to spin faster. This process is called vortex stretching. This process occurs from the ground up and yes it does mean a tornado can form at the ground first. Tornadoes are ranked on the enhanced Fujita scale, which runs from F0 to F5.

A tornado not on the ground is called a funnel cloud and a tornado over water is called a waterspout. While the United States has more tornadoes than anywhere else in the world, they do occur in Europe, Australia and parts of southern Africa. One of the main reasons we don’t see many tornadoes here in New England is that we have the cool ocean to our east. Ocean air is exactly what thunderstorms don’t want.

Cool air knocks down the strong updrafts in a supercell storm and causes them to weaken rapidly. Often a line of strong storms in western New England becomes a weak line of showers by the time it hits Boston and Cape Cod.

Each year, many people are killed or seriously injured by tornadoes despite advance warning. Some did not hear the warning while others received the warning but did not believe a tornado would actually affect them. The preparedness information in this section combined with timely severe weather watches and warnings could save your life in the event a tornado threatens your area.

After you have received the warning or observed threatening skies, YOU must make the decision to seek shelter before the storm arrives. It could be the most important decision you will ever make!

“The earth is warming. Carbon emissions are increasing,” said Sarene Marshall, Managing Director for The Nature Conservancy’s Global Climate Change Team. “And they both are connected to the increased intensity and severity of storms that we both are witnessing today, and are going to see more of in the coming decades.”

We at GreenDustries are taking down the level of “Carbon Dioxide” by replacing all packaging for burger and fries with our PleatPak and Magic Bag, our material used for those two products are made from 100% RECYCLED Paper, reducing the world foot print significantly.

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