Tropical cyclone



A tropical cyclone is a rapidly-rotating storm system accompanied by strong winds and thunderstorms, originating in the tropics but not necessarily ending there. There are various local names depending on the area they occur: when they begin in the Atlantic Ocean and northeast Pacific Ocean they are called hurricanes; in the Indian Ocean and the northwestern Pacific they are called typhoons, and elsewhere tropical cyclones or cyclonic storms.

They can be incredibly destructive, causing billions of pounds of property damage and significant loss of life. But on the lighter side there is a lot of insanity about them including ideas for how they can be stopped or controlled using magic, nuclear weapons, etc.

The facts
The science behind the formation of hurricanes is well understood and scientists know the conditions required to create one. Basically it requires the following (although they won't necessarily be sufficient to produce a hurricane): The basic principle of a thunderstorm is that warm, wet air rises in an area of low pressure. This intensifies the low pressure below, into which more air rushes. Inside the storm system, moisture in the air condenses out and falls as rain; condensation releases heat which causes further rising air and draws more air into the bottom of the storm. Coriolis forces cause everything to spin, and as air rushes towards the center, conservation of angular momentum causes it to spin faster and faster.
 * 1) An existing weather disruption such as a a trough of low pressure over the tropics.
 * 2) A lot of warm water, at least 26°C (79°F) to a depth of 50 metres (165 feet), which provides the energy.
 * 3) A location a little away from the equator where the coriolis force can provide rotational energy, but close enough to provide warm water.
 * 4) High relative humidity.
 * 5) Thunderstorms, where rising water vapor condenses, providing even more heat and energy.
 * 6) Low wind shear initially, meaning there should be little variation in wind speed and direction in the area where the hurricane forms.

Hurricanes are typically classified according to the Saffir-Simpson Hurricane Wind Scale, where they are split into categories based on their top wind speed, with Category 1 being from 74-95 mph (119-152 km/h) while Category 5 is 157 mph (253 km/h) or higher. However, this scale isn't always a good indicator of how destructive a hurricane will be, since that also depends on factors like the amount of flooding the hurricane will cause, how populated the affected area is and the quality of the infrastructure in the area, so even a Category 1 hurricane can be devastating in the right circumstances. In fact, Hurricane Fifi, the third-deadliest Atlantic hurricane on record, was "only" a Category 2.

Climate change additionally has a significant effect on recent hurricanes. While it's unclear if climate change will cause more hurricanes, it does seem to be causing the existing hurricanes to become stronger, with the amount of Category 4 and 5 storms increasing over time.

Nuking hurricanes
A number of people have suggested using nuclear weapons as a defense against hurricanes, including in August 2019 Donald Trump.

There are various reasons why this is a stupid idea. Primarily, it won't work because cyclones are much more powerful than nuclear weapons. One estimate has 5.2x1019 joules/day for an average cyclone. A one megaton bomb yields 4.18 x 1015 joules; the largest US bomb is the rated at 1.2 megatons or 5.0 x 1015 joules. Hurricanes are also very big: typically 300 miles across, far larger than the size of a nuclear explosion. Also, it won't be a good idea because of nuclear fallout. Finally, there's no clear understanding from the proposers on how a storm system works. A hurricane arises out of warm sea temperatures, deep water, and an unstable atmosphere, none of which a nuclear bomb can address in the long term.

This suggestion pops up often enough that the United States' National Oceanic and Atmospheric Administration (NOAA) has an entire section on their FAQ about tropical cyclones dedicated to debunking the idea.

Controlling hurricanes
Weather modification (weather control) has been tried many times by different governments. Cloud seeding is the most commonly used technique, and has shown some modest successes, although it only works when atmospheric conditions are right for rain and seems to be at best giving a bit of a nudge to rain that would fall anyway. Various schemes have been proposed to weaken hurricanes: typically they either involve disrupting the wind flow by promoting smaller storms to use up some of the energy; or methods to reduce water content in the hurricane. Despite the occasional successes of cloud seeding in small areas, when controlling tropical cyclones one of the chief problems is the enormous scale, far larger than a thunderstorm or any scheme that can create or modify rainfall on a town or area of farmland.

As with other forms of weather control, one of the most widely proposed and well studied is by seeding with silver iodide, which can cause water suspended in the air to condense into raindrops and fall to earth, thereby weakening the storm before it reaches landfall. In the 1960s, Project STORMFURY was an American research program which attempted to use cloud seeding to encourage convection on the edge of the hurricane and weaken the central forces, hence lessening the overall destructive force. Although it claimed to detect modest reductions in windspeed, subsequent testing hasn't shown the technique to be effective.

Other techniques suggested include coating the sea with oil to prevent water droplets from being drawn up into the hurricane, proposed by Alexandre Chorin of the University of California at Berkeley, and tested by Kerry Emanuel of the Massachusetts Institute of Technology. This might work on still seas but hurricane-force winds will break up the ocean's surface and disrupt any attempt. Peter Cordani and his Florida company Dyn-O-Mat proposed using a gel which could absorb 1500 times its weight in water to absorb water from hurricanes; this worked in a small-scale test on a thunderstorm but experts think it would fail on a much larger tropical cyclone. Another idea (from Moshe Alamaro) is to use upward-pointing jet engines to create smaller storms and disrupt a hurricane; again there is the problem of the huge scale of hurricanes compared to the amount of air disruption you could cause.

Creating hurricanes
This is where it gets really crazy. A lot of people believe the US government, other foreign powers, or James Bond-style supervillains have the ability to create hurricanes. One proponent of this is Scott Stevens (@weatherwarsinfo on Twitter), a former TV meteorologist 'weatherman' who resigned after he was found to have lied about his credentials. He suggested that Hurricane Katrina was created by the Japanese Yakuza (organised crime gangs) to take revenge for the dropping of the atomic bombs on Japan in 1945. Stevens also claims that Hurricane Sandy was steered by the US government.

HAARP, a government radio research project which has become one of the biggest bogeymen of conspiracy theorists, is also implicated in these fantasies of weather control. Presumably because it's all electricity, whether electrical storm or radio waves, it's all the same, in the minds of conspiracy theorists. This disregards the huge difference in energy between HAARP and a tropical cyclone.

The idea that the US government would be deliberately destroying large parts of the country is somewhat incomprehensible. Why would it? The answers are astonishing. Rush Limbaugh excelled in coming up with multiple ideas, each stupider than the last. In 2016 he suggested that storms were being created by environmentalists to push a climate change/global warming agenda, so that they could take away your cars and oil and tax you to penury. In 2017 he revised his theories and suggested it was a conspiracy to sell bottled water and other survivalist supplies. Because if you had the ability to control the weather, you'd be using it to sell Evian?

The idea that hurricanes can be created faces the same problems as the idea that they can be moved or destroyed: they are created by vast natural phenomena when huge bodies of warm air and water meet other colder bodies over vast distances and areas. But the idea of clandestine weather modification is even stupider than the idea of nuking hurricanes out of existence because it must be done secretly. As though one could warm billions of tons of seawater without anybody noticing.