Pre-Testing

Haha:) We have found a pre-testing of hurricane.

We need to "jiayou"

It would be possible to erect such a line of vertical gas pipes out in the desert. A person or sensor could sit in a chair five or ten miles away, at the center-point of the slight curvature of the array. When the (distant) wall-of-fire is ignited, it might be visible as a brief flash on the horizon. Then, if the concept works as expected, the person or sensor would feel an intense gust of wind maybe a minute later. If enough power was generated, and if the focusing effect performed acceptably, and if the frictional losses in those miles were not too severe, that single gust of wind would hopefully be of at least gale force. If such an effect can be accomplished, from several miles away, the concept seems almost certain to work at de-stabilizing a hurricane.

Hurricane: Know the Terms

Familiarize yourself with these terms to help identify a hurricane hazard:
Tropical Depression
An organized system of clouds and thunderstorms with a defined surface circulation and maximum sustained winds of 38 MPH (33 knots) or less. Sustained winds are defined as one-minute average wind measured at about 33 ft (10 meters) above the surface.
Tropical Storm
An organized system of strong thunderstorms with a defined surface circulation and maximum sustained winds of 39–73 MPH (34–63 knots).
Hurricane
An intense tropical weather system of strong thunderstorms with a well-defined surface circulation and maximum sustained winds of 74 MPH (64 knots) or higher.
Storm Surge
A dome of water pushed onshore by hurricane and tropical storm winds. Storm surges can reach 25 feet high and be 50–1000 miles wide.
Storm Tide
A combination of storm surge and the normal tide (i.e., a 15-foot storm surge combined with a 2-foot normal high tide over the mean sea level created a 17-foot storm tide).
Hurricane/Tropical Storm Watch
Hurricane/tropical storm conditions are possible in the specified area, usually within 36 hours. Tune in to NOAA Weather Radio, commercial radio, or television for information.
Hurricane/Tropical Storm Warning
Hurricane/tropical storm conditions are expected in the specified area, usually within 24 hours.
Short Term Watches and Warnings
These warnings provide detailed information about specific hurricane threats, such as flash floods and tornadoes.

During a Hurricane

If a hurricane is likely in your area, you should:
Listen to the radio or TV for information.

Secure your home, close storm shutters, and secure outdoor objects or bring them indoors.

Turn off utilities if instructed to do so. Otherwise, turn the refrigerator thermostat to its coldest setting and keep its doors closed.

Turn off propane tanks.· Avoid using the phone, except for serious emergencies.

Moor your boat if time permits.

Ensure a supply of water for sanitary purposes such as cleaning and flushing toilets. Fill the bathtub and other large containers with water.
You should evacuate under the following conditions:
If you are directed by local authorities to do so. Be sure to follow their instructions.

If you live in a mobile home or temporary structure—such shelters are particularly hazardous during hurricanes no matter how well fastened to the ground.

If you live in a high-rise building—hurricane winds are stronger at higher elevations.

If you live on the coast, on a floodplain, near a river, or on an inland waterway.

If you feel you are in danger.
If you are unable to evacuate, go to your safe room. If you do not have one, follow these guidelines:
Stay indoors during the hurricane and away from windows and glass doors.

Close all interior doors—secure and brace external doors.

Keep curtains and blinds closed. Do not be fooled if there is a lull; it could be the eye of the storm - winds will pick up again.

Take refuge in a small interior room, closet, or hallway on the lowest level.

Lie on the floor under a table or another sturdy object.

Before a Hurricane

To prepare for a hurricane, you should take the following measures:
Make plans to secure your property. Permanent storm shutters offer the best protection for windows. A second option is to board up windows with 5/8” marine plywood, cut to fit and ready to install. Tape does not prevent windows from breaking.

Install straps or additional clips to securely fasten your roof to the frame structure. This will reduce roof damage.

Be sure trees and shrubs around your home are well trimmed.

Clear loose and clogged rain gutters and downspouts.

Determine how and where to secure your boat.

Consider building a safe room

During a hurricane, homes, businesses, public buildings, and infrastructure may be damaged or destroyed by many different storm hazards. Debris can break windows and doors, allowing high winds and rain inside the home. In extreme storms (such as Hurricanes Hugo, Andrew and Katrina), the force of the wind alone can cause tremendous devastation, as trees and power lines topple and weak elements of homes and buildings fail. Roads and bridges can be washed away and homes saturated by flooding. Destructive tornadoes can also be present well away from the storms center during landfall. Yet, storm surge alone poses the highest threat to life and destruction in many coastal areas throughout the United States and territories. And these threats are not limited to the coastline -- they can extend hundreds of miles inland, under the right conditions.

Hurricane: A severe tropical cyclone with wind speeds in excess of 74 mph. As they move ashore, they bring high winds, tornadoes, torrential rains, and flooding.

One of the most dramatic, damaging, and potentially deadly events that occur in this country is a hurricane.
Hurricanes are products of the tropical ocean and atmosphere. Powered by heat from the sea, they are steered erratically by the easterly trade winds and the temperate westerly winds, as well as by their own energy. As they move ashore, they bring with them a storm surge of ocean water along the coastline, high winds, tornadoes, torrential rains, and flooding.
Each year on average, ten tropical storms develop over the Atlantic Ocean, Caribbean Sea, or Gulf of Mexico. About six of these typically strengthen enough to become hurricanes. Many of these remain over the ocean with little or no impact on the continental United States. However, about five hurricanes strike the United States coastline every three years. Of these five, two will be major hurricanes measuring a category 3 or higher (defined as having winds above 111 miles per hour) on the Saffir-Simpson Scale. These storms can end up costing our nation millions, if not billions, of dollars in damages.

Sth

To reduce the catastrophic loss of life and material damage caused by hurricanes we need better forecasts both of their paths and intensities. Currently forecasts of path are too error-prone to be of much practical use beyond three days in advance, and predictions of intensity change are even less developed. Furthermore, last year’s record-breaking Atlantic hurricane season has fuelled fears that global warming may be responsible for increasing the frequency and intensity of hurricanes. Although controversial, such a link would be of vital importance to the hundreds of millions of people living in hurricane-prone areas.Many features of hurricanes can be explained in terms of classical physics – such as Newton's second law and the thermodynamics of moist air. By understanding the basic physics behind the growth and progress of hurricanes, physicists are contributing to a global effort to obtain better hurricane forecast models.

http://physicsworld.com/cws/article/print/24997

The Physics of Hurricanes~

Understanding Tropical Cyclones© Katharine M. J. OsborneAug 11, 2006Hurricanes have hit the popular consciousness hard - the increased hurricane activity has everyone worried - but how do they work?Hurricanes, which are also known as typhoons in Asia, and are more properly called tropical cyclones, are amongst the most damaging and deadly natural phenomena. Recent years have seen an increase in tropical cyclone activity, due in part to a natural cycle of activity, but likely due to global warming as well. Warm tropical water is key to the formation of tropical cyclones.Tropical cyclones typical form in the ocean about 5 degrees from the Earth's equator over water heated to about 26 degrees Celsius to a depth of about 50m, though tropical cyclones can form elsewhere. In 1996 for instance, a tropical cyclone briefly formed over Lake Huron in the middle of North America. Typically though, tropical cyclones require the coriolis effect in order to form, which gives the storm it's rotation. This effect is greatest nearer the equator. Cyclones also require low wind shear to form, meaning that wind speeds and directions close to the surface of the ocean aren't much different from wind speed and direction higher in the atmosphere. High wind shear will tear a storm system apart.The interior of a forming cyclone is like a huge heat engine. Warm surface water evaporates and rises as moist air high into the atmosphere. As it reaches the top of the troposphere, the layer of the atmosphere in which weather takes place, the moist air condenses. This converts heat to a tiny amount of mechanical energy. This mechanical energy adds to a down draft of wind on the outside of the system, which falls to the ocean surface and helps to pick up more moist air. This starts a positive feedback loop that helps to increase the formation of the system.Tropical cyclones actually help to cool the ocean by drawing heat out and converting it into mechanical energy (wind). They can carry this energy pole-ward, so that along with ocean currents, no one area of the ocean becomes over heated. Even this balance is limited. As the overall amount of energy in the Earth's atmosphere increases, more and more tropical cyclones will form.

What is it?

Hah? What's this? It is terribly difficult!
http://www.sjsu.edu/faculty/watkins/hurricanepaths.htm

maybe we could use some of it!

Hurricane again

A swirling powerful storm that is formed over a warm sea is called a hurricane. Hurricanes can cause significant amounts of damage to anything in its path through fierce winds, torrential rains, flooding, and its huge waves crashing ashore.
Hurricanes can kill more people and destroy more property than every other natural disaster.
The calm central where the winds of the hurricane swirl around is called the eye. The eye is surrounded by a band of dark, tall clouds called the eyewall. The eye is serene as it is free of large clouds an rain. The eye is usually between 10 and 20 miles in diameter.
The strongest winds in the hurricane's eyewall are caused by the large changes in pressure.

http://physicsofhurricanes.homestead.com/index.html

Hurricanes are tropical storms with winds over 74 miles per hour and lots of rainfall. They start over warm, tropical oceans. Hurricanes get their heat and energy from the warm ocean waters. As the water evaporates, the hurricane gets stronger. They can last longer, and sometimes move much further, over water than over land. The combination of heat and moisture, along with the right wind conditions, can create a new hurricane. When a hurricane hits land, it tends to weaken because it has lost its source of energy, the warm ocean waters. Hurricanes are known as ‘typhoons’ in the western Pacific, ‘cyclones’ in the Indian Ocean, and ‘baguios’ in the Philippines. Each storm usually lasts for an average of nine days. The ocean water temperature has to be above 79 degrees in order for a hurricane to be formed, so they normally appear in late summer and early fall when the conditions are right. Hurricanes have two main parts. The first is the eye of the hurricane, which is a calm area in the center of the storm. Usually, the eye of a hurricane measures about 20 miles in diameter, and has very few clouds. The second part is the wall of clouds that surrounds the calm eye, called the eyewall. The eyewall is the area inside the hurricane where the winds and rain are the worst. Winds can be up to 186 mph! When the eye of a hurricane passes over a region, the winds decrease to just a gentle breeze, and the rain stops. You may even be able to see the sun during the day or the stars at night. Then the rest of the storm passes and the wind suddenly changes directions and becomes strong again. In the northern hemisphere hurricanes usually rotate counter-clockwise. Hurricanes can be very dangerous. The strong winds and heavy rains can raise sea levels and cause flooding. Hurricanes can create tornadoes. Often the right side of a hurricane causes the worst damage. Meteorologists give hurricanes names, which are reused unless the storm is particularly destructive. The names used to be all women's names, but since 1979, men's names have been used, too. Six lists are used in rotation. Thus, the 2004 list will be used again in 2010. Is your name going to be used for a hurricane? Check here! A name is retired if that hurricane caused a lot of damage or many deaths. There are three types of damage caused by hurricanes: Wind Damage: Hurricane-force winds, 74 mph or more, can destroy poorly constructed buildings and mobile homes. Debris, such as signs, roofing material, siding, and small items left outside, become flying missiles in hurricanes. Winds can often stay strong well over land. Storm Surge Damage: Heavy ocean waves caused by a hurricane is a storm surge. They are very dangerous, and a major reason why you must stay away from the ocean during a hurricane warning or hurricane. It can often be 50 to 100 miles wide. It sweeps across the coastline near where a hurricane makes landfall. The surge of high water topped by waves is devastating. The stronger the hurricane and the shallower the offshore water, the higher the surge will be. Along the immediate coast, storm surge is the greatest threat to life and property. Flood Damage: Widespread torrential rains often in excess of 6 inches can produce deadly and destructive floods. This is the major threat to areas well inland.

Storm Surge

In less than a 4 week period in 1992, two major hurricanes hit the United States leaving an unprecedented amount of destruction. First Hurricane Andrew pounded Florida and Louisiana to become the most expensive natural disaster in U.S. history, with damage estimates in the range of $15 billion to $30 billion. Then 3 weeks later, Hurricane Iniki affected three Hawaiian islands resulting in over $1 billion in damage, particularly in Kauai.
Hurricanes and their potential for destruction are rated using a scale from 1 to 5 called the Saffir-Simpson Scale. A Category 1 hurricane is the least dangerous and a Category 5 hurricane is the most dangerous.
Saffir-Simpson Hurricane Scale
Category
Damage
Wind Speed
Storm Surge
1
Minimal
74-95 mph
4-5 feet
2
Moderate
96-110 mph
6-8 feet
3
Extensive
111-130 mph
9-12 feet
4
Extreme
131-155 mph
13-18 feet
5
Catastrophic
155+ mph
18+ feet
Did You Know:
Hurricane winds weaken with height.
The centers of hurricanes are warmer than their surroundings.
Air sinks at the center of a hurricane.
Hurricanes weaken rapidly over land.
Hurricane Watch: Means a hurricane is possible within 36 hours. Listen to the news for new information.
Hurricane Warning: Means a hurricane is expected within 24 hours. You may have to evacuate!

How Do Hurricanes Form?

Tropical storm and hurricane prediction probably never will be an exact science, but the reasons for storm formation are well understood by the scientific community. There are several elements that—when combined at the "right" amount of time and under the "right" conditions—will create a hurricane, according to the National Oceanic and Atmospheric Association (NOAA).
The beginning of life for any hurricane is a pre-existing tropical disturbance—an area of low atmospheric pressure in the air over the tropical Atlantic Ocean near Carribean islands, such as Bermuda and the Bahamas.

The warmth and moisture of the ocean during late summer and early fall months (when ocean waters reach their highest temperatures) energizes the pre-storm conditions and leads to thunderstorms.
If thunderstorms persist and winds pick up to 40 miles per hour, the tropical disturbance officially becomes a tropical storm. At this point, the National Hurricane Center names the storm, working from a pre-determined list of names that is recycled every six years. Meteorologists all over the country know to keep a close eye on the now-named storm, although many tropical storms weaken and die before becoming hurricanes.
'Heat Engine': The Energy Behind a Hurricane
Tropical storms that continue to intensify will keep pulling in warm and humid air from the lower atmosphere while spitting out cooler, drier air into the upper atmosphere. According to Chris Landsea of NOAA's hurricane research division, at this point in its development, the storm system operates like a huge "heat engine."
"The 'heat engine' gets its energy from warm, humid air over the tropical ocean and releases this heat through the condensation of water vapor," said Landsea. This energy release is what drives the powerful winds of a hurricane.
The force of the release is tremendous—the amount of heat energy released by an average hurricane is equivalent to the amount of electric energy produced by the U.S. in an entire year. A small portion of the energy released actually warms what has become the inner core of the storm. As the temperature of the air in the inner core rises, its pressure drops, increasing the speed and intensity of the winds swirling around it. These stronger winds bring more warm, moist air to the clouds surrounding the inner core of the storm further fueling its energy. When the swirling winds reach a speed of 74 miles per hour or more, the tropical storm becomes a hurricane.
Hurricane Ratings
Once a storm officially becomes a hurricane, it receives an intensity rating based on its wind speed and potential to cause damage. The rating system that is used by the National Weather Service is called the Saffir-Simpson scale. As a hurricane develops, its intensity rating often changes. In 1985, for example, Hurricane Opal grew from a Category One into a Category Four hurricane in just 18 hours.
Category One hurricanes have wind speeds between 74 and 95 miles per hour and are expected to cause minimal damage to buildings and homes. Trees, shrubbery and mobile homes tend to bear the brunt of the damage caused by Category One hurricanes.

Hurricane Bonnie, which hit the North Carolina coast in 1998, was a Category Two hurricane and caused both flooding of low-lying areas and considerable damage to trees.
With wind speeds reaching 100 miles per hour, this is typical of a Category Two storm. Category Three and Four hurricanes are characterized by even stronger winds and much more damage to homes, buildings and trees.
The most intense classification of a storm is the Category Five hurricane. A Category Five storm will have sustained winds of 155 miles per hour or more and is capable of extensive damage. Hurricane Gilbert of 1988 was the strongest Category Five hurricane ever, destroying Jamaica with wind speeds upwards of 180 miles per hour.
Anatomy of a Storm

The inner core of the hurricane is known as the eye of the storm—a calm, often clear-skied patch where winds are lightest and pressure is lowest. Surrounding the paradoxically calm region of the hurricane is a ring of clouds called the eyewall. The eyewall clouds are thunderstorm clouds, and it is in this region of the hurricane where the heaviest rains and winds originate. During Hurricane Camille, which pummeled the Gulf Coast in 1968, winds in the eyewall reached speeds in excess of 200 miles per hour. The outermost ring of the hurricane is made up of bands of heavy rains that swirl inward toward the storm's center, called spiral rainbands.
Weather Report
While the clouds and rainbands are forming in the sky above, the weather on the land below the hurricane turns nasty. The spiraling winds that accompany hurricanes can extend even further beyond the eye of the storm. Typically, hurricanes are about 300 miles wide, so they can affect fairly large areas at one time.
Unfortunately for those in its path, a hurricane's speed of travel is hard to predict and varies greatly from storm to storm. Weather experts have calculated that hurricanes move forward at an average speed of 15-20 miles per hour, but a big storm also has the potential to linger over one area for a while, causing torrential rains, or move so quickly that there is no time to prepare for its arrival.
Eventually, a hurricane's energy begins to dissipate and the storm weakens. Weather experts have identified several factors that contribute to a hurricane's demise, including the storm's movement over cooler water or drier areas. Even when a hurricane appears to have blown over, however, it can potentially reintensify if it hits weather conditions that are favorable for its development.
El Niño Effect
El Niño is a weather phenomenon that causes equatorial Pacific Ocean temperatures to be warmer than usual. El Niño periods occur in cycles, and the most recent El Niño event we've experienced was in 1997-98. During this time, there were fewer Atlantic hurricanes than the average number during hurricane season. Weather experts say that warm El Nño events are characterized by decrease in the number of tropical storms and hurricanes in the Atlantic, Gulf of Mexico and the Caribbean Sea because of the increased wind shear. The wind shear associated with El Niño essentially cuts a storm off during its development, by hindering the formation of a vertical ring of clouds. The shear actually shaves off some of the clouds, which creates a slant in the cloudwall. When a storm is slanted, the heat energy released from condensation is spread out over a larger area and doesn't necessarily feed back into the storm system to strengthen it.

A La Niña period brings weather conditions opposite to those that are associated with El Niño. La Niña brings cooler equatorial Pacific Ocean temperatures and decreased wind shear in the tropical Atlantic region-increasing the chances that a tropical disturbance will in fact develop into a hurricane.
Hurricane Mitch, which caused devastating damage to Nicaragua and Honduras in October 1998, occurred during a La Niña period. However, since Hurricane Mitch followed a lot of media hype about El Niño, said NOAA's Landsea, many people erroneously assumed that El Niño was responsible for Mitch.
"This was definitely not the case," said Landsea. "The big El Niño of 1997-98 caused a reduction in Atlantic hurricanes, with only three forming in 1997. But the El Niño finished by the spring of 1998, and was quickly replaced by La Niña by the time Hurricane Mitch occurred. We have more or less been in that same La Niña-and it has boosted the Atlantic hurricane activity both in 1998 and last year-though it is currently fading."
Preparing for the Storm
No matter how intense a hurricane season turns out to be, it is always good to be prepared for a big storm. Whether facing a hurricane watch or warning, the Red Cross recommends that the public get and stay prepared, which includes developing an evacuation plan.
When a hurricane watch is issued (meaning that hurricane conditions are possible within 36 hours), people in affected areas should tune in to local radio or TV stations for up-to-date storm information. Consider bringing any lawn furniture capable of being picked up by the wind inside and preparing houses for high winds. While many people think that taping windows shut is sufficient to prevent windows from breaking, the Red Cross recommends using something stronger, such as hurricane shutters or plywood.
When a hurricane warning is issued (meaning that hurricane conditions are expected in the specified area, usually within 24 hours), the Red Cross advises being prepared to evacuate to a shelter if local officials indicate to do so.
If the storm hits and it is not necessary to leave your home, the Red Cross advises staying away from windows and continuing to pay attention to the development of the storm. As previously mentioned, blue skies and calm winds do not necessarily mean that the hurricane is over, just that the eye of the storm is moving over the area. Once the eye passes over, the storm will pick up again with winds blowing from the opposite direction.

Physics of Hurricane

FormationNo one yet really understands how and why hurricanes form. Logically, any circulating flow of air should experience frictional energy losses in moving past stationary exterior air. This is why the vast majority of "dust devils" and other small scale vortices dissipate in a matter of seconds. Larger scale vortices, such as the common weather cyclones and anti-cyclones, persist longer, but still eventually succumb soon to these frictional losses.
Obviously, there is something unique in the formation of a hurricane, which overcomes this natural effect of energy dissipation. Whatever those unique characteristics are, they certainly rely on an effective application of a (natural) forced vibration and its resonant effects. A hurricane does not form instantly. It gradually grows in size and strength and intensity. This is an example of the physics concept of amplification (magnification) at a resonant frequency, like in the public address amplifier 'feedback loop' example mentioned above.
Since hurricanes must then necessarily FORM due to an extended exposure to resonant effects that magnify their power and intensity, this approach is meant to use the same concept against them! At very early stages in their development, an assortment of approaches might be effective, from introducing out-of-phase rotational energy AT the natural frequency (in an application of the Quadrupole approach) to introducing entirely different resonant frequencies, either near the resonant frequency or at harmonic multiples of it (with the intention of driving the storm formation into several other, smaller circulations, so that the large later hurricane could not form).
The bulk of this presentation is based on the assumption that an organized circulation has already formed and must be dealt with. Once the resonance effect has begun to substantially magnify, attempting to modify the natural frequency is very difficult, and so the basic approaches described here focus on the fact that the natural frequency is already well established. With this fact given, the methods described above seems most likely to best reduce or dissipate the storm. As has been noted though, a number of variations could be tried, to see which approach most effectively de-stabilized the hurricane. It might even be that different approaches are most effect at deterring the initial formation of the storms and at de-stabilizing well-established ones.
As should be obvious in all this, since a hurricane initially takes many hours of stable resonant conditions in first forming, it would also certainly take quite a few hours of introducing detrimental harmonic resonant energy in order to degrade it.

The Physics of Tornadoes and Hurricanes

Tornadoes and hurricanes are weather phenomena that are examples of physical vortexes.

A tornado is a violent windstorm with a twisting, funnel shape cloud and is usually spawned by thunderstorms when cool air and warm air meet, forcing warm air to rise quickly. Damage from tornadoes are due to high speed winds and flying debris.

A hurricane is tropical storm which also has a twisting, funnel shaped form but is much larger than a tornado. In the centre of a hurricane is a calm area called the "eye". High winds, torrential rain, floods, and storm surges caused when hurricanes come near or over land result in significant damage over large areas.

Archimedes Principle

Archimedes's Principle says that a body immersed in a fluid is buoyed up by a force equal to the weight of the displaced fluid.
The relative density of the object compared to the density of the fluid determines whether it will sink or float.
The pressure due to the fluid is equal to pgh (density times acceleration due to gravity, times height) and when applied to an area, gives the force.

h1
h2
Fg
Fb
h=h2-h1


Therefore the force at the top of the object is:
P1A = pfluidgh1 A
and the force at the bottom of the object is:
P2A = pfluidgh2 A
so the buoyant force pushing up on the object is:
Fb = F2 – F1
= pfluidgA (h2-h1)
= pfluidgAh
= pfluidgV

which is the density of the fluid, times acceleration due to gravity, times the volume of the fluid displaced.

The formula: Fb = pfluidgV
applies not only to a rectangular object, but can be generalized to an object with any shape.
If the buoyant force is more than the weight of the object, this means that the object's density is less than the fluid's density. This results in the object rising or floating up.
If the buoyant force is less than the weight of the object, this means that the object's density is more than the fluid's density. This results in the object sinking.

Also when objects are heated, they expand.
density formula: p=m/V, where p is density, m is mass, and V is volume
When a pocket of air is heated, it expands and the volume increases, thus density decreases. And if the density of the air pocket is less than the density of the surrounding cooler air it will rise.

Rising air in the centre meets less resistance because it is surrounded by air that is also rising.
Rising air creates a vacuum causing cooler air from the sides to move in to replace the rising air. This causes a wind which further pushes the rising air.

Angular Momentum

Ordinary linear momentum is a measure of an object's tendency to move at constant speed along a straight path. Linear momentum depends on speed and mass.
When objects moved in curved paths, we can generalize the idea of linear momentum to something called angular momentum, an object's tendency to spin.
Like linear momentum, the total angular momentum of an isolated object is conserved.
Imagine an object with mass, rotating around an axis. Here, the angular momentum is the product of its mass, velocity (tangential), and radius (the distance from the axis point around which the object is spinning around).
L = mvr


Note that this applies to an object that has its mass at the distance r from the axis.
However, we can generalize this to an object whose mass is distributed all along the distance r and not just at the end of that distance r. For example, the body of a figure skater has most of its mass near the axis of rotation, and the mass of his or her arms and hands at a farther distance out.
Let us assume all the mass is at the distance r from the axis of rotation.
Conservation of angular momentum then explains why figure skaters or divers spin faster when they bring in their arms or tuck themselves in a roll.

For angular momentum to conserve in a spin, the angular momentum before must equal the angular momentum after.
The mass of the figure skater doesn't change. So if the radius decreases (by the skater bringing in their arms), then the velocity increases.
Lbefore = Lafter
mviri = mvfrf


Rotational Force

Acceleration is the change of velocity in a short period of time:
a=Δv/Δt
When an object is rotating around something, the acceleration force to keep it rotating is:
F = ma = m v2 / r
The acceleration causes the direction of velocity to continually change to keep it rotating.
When you swing a ball on a string, you exert a force on the string, causing a tension, which then exerts a force on the ball.
At the same time, the ball exerts an equal amount of force in the opposite direction. The ball exerts a force on the string, causing a tension, which then exerts a force on your hand.


Coriolis Force

The •Coriolis Force is an inertial force that was described by the French engineer-mathematician Gustave Gaspard Coriolis in 1835.
In a rotating frame of reference, it is an inertial force acting to the right of the direction of movement when rotating counter-clockwise and to the left of the direction of movement when rotating clockwise.
It occurs because the Earth rotates eastward and it rotates faster (tangentially) as you approach the Equator and slower at the poles.

The Coriolis force is very, very weak and plays an insignificant role in the spinning of water in a sink or a toilet. The way the water spins is more likely due to the oval shape of the bowl or the off centre drain.


Tornadoes

The funnel of a tornado is visible due to the condensation of water vapor from the pressure of the spinning wind.
They have damage paths that can be 1.5 km wide and up to 75 km long.
There is enough force to pick up cars and rip homes to shreds, turning the debris into potentially lethal missiles.
There are an average of 1000 per year reported in the US and result in around 80 deaths and 1500 injuries (NOAA).
More tornadoes form in the mid western United States than any where else in the world. They usually occur in the fall and spring.

Steps of formation:
Warm, moist winds flow up (and a little east due to the Coriolis Force) from the Gulf of Mexico.
Air becomes unstable because warm air rises and continues to rise due to the heat from the sun.
The air cools as it rises higher and condenses into clouds.
A cold front containing cooler, drier air from the north in Canada flows south focusing the rising air.
The Rockies also help divert northern winds eastward towards the flat plains in central US.
Interactions between air at different altitudes causes storms, lightning, rain, air circulation, and strengthening the rotating updraft.
A column of spinning air can form, which narrows and spins faster and extends higher into the storm.


Fujita Scale

The Fujita Scale classifies tornadoes according to the damage they cause. This is because the size of a tornado is not an indication of its intensity and so there can be large but weak tornadoes or small but powerful ones.
It does try to link wind speeds with damage. However, there are some problems with this measurement system:
can only be measured after the tornado is gone and damage is assessed
tornadoes cannot be measured if it results in little damage
note: No F6 tornadoes have been officially reported as the winds are highly unlikely and they would probably be classified as strong F5's. F6 would be difficult to determine as there would be no objects left to study.


Hurricanes

Hurricanes form in the tropics where the air and water are warm and moist.
Ocean water is heated and evaporates, which takes in energy from the ocean. The warm air rises quickly as it is heated and forms a low pressure system over a large area, creating tropical storms.
Like in tornadoes, as the warm air rises, a vacuum forms from the low pressure and to replace the rising air, air from the perimeter is drawn into the centre.
The incoming winds are curved due to Coriolis force and prevailing winds. The rising air, saturated with water, cools and condenses to form clouds.
As the water rises, it cools and condenses, releasing latent heat energy to the surrounding air, causing it to warm further.
At the hurricanes core, wind sinks from being expelled at the top, preventing clouds from forming and creating a calm "eye"
This feedback mechanism continues to intensify as long as there is warm water from which to draw energy.
Once a hurricane moves over land, the large energy supply form the ocean is no longer available and the storm begins to lose its strength and eventually dissipates.

Hurricane Pictures

Continuing

In the Spring of 2002, I went out of my way to try to discuss these matters with the NHC (National Hurricane Center) and related government Agencies, primarily in Florida but also in Colorado, Texas and elsewhere, but they seemed to uninterested in the fact that I am a Physicist and instead simply assumed that hurricanes are too large and too powerful for humans to affect. I believe they may be wrong about that, along the lines of the shattering wineglass mentioned below! However, even if their assumption is right, that we humans are just to puny to affect a hurricane, doesn't it seem at least logical to TRY some fairly simple and inexpensive experiments, in the remote chance it might work?
It has been immensely frustrating to me to watch as terribly destructive hurricanes such as Katrina in 2005 have done such massive damage, where I think there might actually have been a (remote?) possibility of degrading such hurricanes far before they had ever approached land. Had I somehow been more persuasive in getting government personnel to have interest in my concept, who knows whether Katrina might even have ever existed? But in my attempts at dozens of visits and interviews in the Spring of 2002, only a single individual was even willing to spend a few minutes to listen to me (after I had spent a week of my time in trying to provide this information to them!) He was extremely interested and extremely impressed, and he even mentioned that he thought it might have a chance of working. He then mentioned to me a number of rather hare-brained ideas that their Agencies had previously tried, such as flying cargo aircraft filled with many tons of bags of concrete through the Eye of a hurricane and dumping them, in an apparent attempt at paving over the ocean inside the Eye! Unfortunately, he ended the interview by mentioning that he was about to retire shortly and that he no longer had any pull around there. He promised me to try to get some of his colleagues to listen to my concept before he left, but that must not have ever had any effect, as no one ever later contacted me.
By the way, during that same trip in early 2002, I contacted a number of people in and near New Orleans, by phone and by e-mail, including the Mayor of New Orleans and several City Engineers, and also Joe Suhayda, a known researcher on hurricanes who had warned of danger to New Orleans due to hurricanes. None of those people even responded to any of my phone calls or letters. But I had then (more than three years before Katrina) attempted to warn them of aspects of their situation where the Physics indicated great danger. Sadly, no one seemed to have any interest in my concerns then. I might note that when Katrina hit, it had degraded down to a Category 3 hurricane, and also that it had actually entirely MISSED hitting New Orleans! It amazes me that people who later decided to "revise history" portray Katrina as a tremendously damaging hurricane! It was nowhere near as strong as the hurricane Andrew that devastated Florida or a number of other giants. Had Katrina ACTUALLY remained at Category 5 (which it had earlier been) and ACTUALLY hit New Orleans, the devastation probably would have been far greater than what actually happened. But I guess all that is "politics" and "spin" where leaders keep insisting that New Orleans will be "rebuilt better than ever", essentially without any funding to actually do it. However, spending hundreds of billions of dollars more to rebuild that city would be very foolish, as between future, stronger hurricanes and rising sea levels, it may only be 20 years before New Orleans (currently 7 feet BELOW sea level and protected by those 117 miles of dikes) will be forever abandoned as being entirely underwater. My contact with New Orleans at that time was not actually regarding hurricanes, but when I realized that their situation, of slowly sinking into the recent sediment of a river delta, was very similar to the one where I was then attempting to provide a way for Venice Italy to actually physically RAISE their city by around five feet. In any case, hurricane research now really has no way to help them.
As indicated below, this basic concept regarding enabling hurricanes to become unstable and spontaneously degrade was developed by the beginning of 2001, but in early 2004, two new (simpler) mechanisms were recognized as possible to create the necessary shock waves in the perimeter of a hurricane. One would be a precise (due to GPS and precise clocks) repetition of a vertical stack of "percussion bombs" (OUTSIDE the perimeter of the hurricane) to create a vertical-source shock wave to disrupt the smooth circulation flow of the outer hurricane winds. The other is the sequential use of several supersonic aircraft a few miles outside the 50 mph winds of the outer circulation. The sonic boom caused by supersonic objects like aircraft or bullets is actually a shock wave propagating through the air. An aircraft with a nose cone angle of 10°, traveling at Mach 1.1, creates an extremely intense pressure shock wave, as much as 4 PSI, or 100" of barometric pressure, around 68° out away from the tail centerline. If a supersonic aircraft followed a very specific, fairly tight smooth level, logarithmic spiral turn, the resulting continuous shock waves become closer together in the air inward along the radius of the turn. It is possible to shape that logarithmic spiral path so that the sonic boom shock waves from as much as 45 seconds of the supersonic aircraft's flight can all be made to arrive at a desired location a few miles to the side at the same instant, creating an extremely intense (vertical line) shock wave at that single location. Depending on how precisely the aircraft could follow the logarithmic spiral path, an incredible sound intensity could be generated, mathematically around 220 decibels, quite possibly the loudest sound ever heard on Earth! This single wavefront of such extremely loud low-frequency sound exists as a compressed-air shock wave. By following that specific curved path, the natural 4 PSI pressure of a sonic boom shock wave might be increased to over 30 PSI, in that single planned target destination inside the periphery of the hurricane. The premise is that that instantaneous local pressure increase would compress and then expand the air at that location, suddenly creating new air motions at rather high velocities, which we might pre-design. If that were possible, then it might be possible to repeatedly (at a very specific interval to create a resonance) generate such localized air motions to try to disrupt the circulation motions of the hurricane. It is also possible for the aircraft to follow a course of slightly greater radius turn, or a possibly a horizontal somewhat hyperbolic path, to cause a broader (in time) shock wave to appear there, which has the effect of being at a lower frequency. This sudden blast of hurricane-radially-inward wind would act to drive some of the hurricane's winds farther inward, disrupting the normal circular flow, causing ripples to form in the circulation, and somewhat de-stabilizing the hurricane. Several such aircraft would be flown to create repetitive sonic boom disruptions in the same position in the hurricane, to try to inspire the wineglass-like self-destruction of the hurricane.
Every year, dozens of hurricanes (and Pacific typhoons, which are the same thing) do enormous damage in lives and property in several parts of the world. They are enormous, being many miles in diameter, and they have phenomenal amounts of energy and power. Over the years, many speculative concepts have been proposed to try to deal with them, but any such efforts would not be like David and Goliath, but a flea and Goliath. The most powerful machinery that we have fades into inconsequentiality in relation to the size and power of even a moderate hurricane. A "brute force" approach has NO chance of succeeding, even though some very creative and intriguing ideas have been presented and considered.
A very rough estimate of the amount of kinetic energy in a mature hurricane is around 1018 joules, or 1,000,000,000,000,000,000 joules. As a comparison, if every one of the hundred million operating cars in America were run at absolutely full throttle, they all would have to run like that for about 20 hours straight to produce that much energy! That gives a rough idea why traditional methods of Engineering would have no noticeable effect on a hurricane, because of the enormous size and strength. All that energy cannot just be made to disappear, but must somehow be dissipated (converted to other forms of energy, primarily frictional heating of other air).
Current research into hurricanes seems to focus on the central areas, where the winds are highest, near the "eye". However, even superficial calculation shows that the majority of the actual kinetic energy contained in a hurricane resides in the huge outer areas. Even though the winds are slower there, the vast quantity of moving air carries most of the energy of movement. This fact has therefore encouraged this new approach at degrading a hurricane, by attempting to cause disruptions, destabilizations, in the perimeter of the storm, to cause energy to be dispersed there (probably as tornadoes spawned off).
This involves NO attempt to "over-power" the hurricane! Rather, it uses the energy that is already in the hurricane by encouraging some of that energy to get "out-of-phase" with the main circulation of the hurricane. This out-of-phase energy becomes disruptive, with the intended result to create many (small) tornadoes which remove kinetic energy from the main circulation of the hurricane.
It has long been noticed that, in the late stages of a hurricane's existence, many (brief) tornadoes often appear along their borders. Such tornadoes have extremely fast-moving winds, but their relatively small size means they contain only a fraction of the energy of a hurricane. They each therefore remove fairly large amounts of rotational energy from the hurricane in very short periods of time. These tornadoes are clearly a very energy-expensive aspect of hurricanes, and they are never seen early in the life of a hurricane. My interest is to try to use this existing natural phenomenon, but to artificially inspire it to occur much earlier in the life-sequence of a hurricane!
If this tornado-spawning process can be artificially induced, well before a hurricane approaches land, large amounts of the circulation energy should be removable from the hurricane by this process, and the hurricane would then necessarily be degraded in strength. No one could know or plan where the tornadoes might form or where they might go, so it would be critically important to do this process far from all land and human activities. However, the advantage is that tornadoes have very short lifetimes, and never travel very far before self-degrading due to frictional losses, where the main hurricane would have damage-creating potential for many days over a very large region.
It is believed that this effect of tornado-spawning once over land is a primary reason why many hurricanes degrade so very quickly when they are over land, because so much rotational energy is dissipated to the many tornadoes. The kinetic energy or rotation of the hurricane cannot just disappear, so it must be converted into other forms of energy, almost certainly being frictional heat energy in the air. This seems to imply that the air temperature must rise as a hurricane degrades. Beginning in 2002, technology has become capable of monitoring this data over the entire region of a hurricane, so this premise should soon be proven or disproven, assuming that someone decides to measure it!
The speculation here is that a hurricane that can be artificially caused to spawn hundreds of such tornadoes (while still over the ocean) might thereby quickly give up substantial amounts of its kinetic rotational energy to those tornadoes and the hurricane remaining would thereby rapidly get weaker. Once separated from the hurricane, each tornado would soon lose its kinetic energy by normal friction to the surrounding air. That two-stage process would therefore accomplish dissipating a great deal of energy rather quickly. This seems like a possibility worth looking into.
One way or another, when a hurricane disappears, all that kinetic energy of rotation must become converted into frictional heating of local air and ground. It has long been believed that friction with the ground is a major cause of the relatively rapid diminution of a hurricane's strength when over land. However, the resulting increase in that ground's temperature would be significant, due to the enormous amount of kinetic energy which must be dissipated. Clearly, the creation of peripheral tornadoes, which quickly dissipate and therefore give up their rotational kinetic energy into frictional heating of the air, must also represent a significant method of hurricane energy reduction.
This concept is here seen as a significant possibility regarding how to remove large amounts of energy from hurricanes, to inspire them to spontaneously spawn tornadoes earlier in their existence.
It seems prudent to try to deal with a hurricane well before it nears any land, out in the open ocean. For one thing, it then has less total kinetic energy of rotating winds to try to dissipate. We wish to (externally) cause small turbulences in the outer circulation of it, with the intent of encouraging it to form those tornadoes at that time. Being away from land and people, such tornadoes would not cause any damage, but they would collectively remove large amounts of kinetic energy from the hurricane circulation, thereby weakening it. The premise of this application is that if hundreds of such tornadoes could be artificially spawned from a hurricane, the remaining kinetic energy would be greatly reduced, either degrading or dissipating the hurricane.
There are several other possible applications of this concept, mentioned below, but this tornado-inducer might be the simplest of them.