Mankind has tamed many forces of nature, from mighty rivers harnessed in dams to tiny atoms vibrating in the confines of power stations. Yet tornadoes remain as wild, raw, and as terrifying a force, as it was thousands of years ago. Unlike hurricanes, tornadoes can not be reliably predicted and prepared for. There is no time to evacuate or put cardboard over the windows. Tornadoes strike suddenly, often at the time and place where they are least expected. In many cases, sudden onslaught of deadly winds leaves no time to hide in the shelter. And in most cases, there is no shelter to hide in, and human is left one on one with the fury of nature.
According to the US National Oceanographic and Atmospheric Administration, in an average year, 800 tornadoes are reported nationwide. These tornadoes reap the grizzly yearly harvest of 80 deaths and over 1,500 injuries in the United States alone.
The total number of tornadoes is likely much higher than the actual number reported. Scarce population of the Western states likely reduces the number of tornadoes noticed and reported. As the population of the United States steadily grows, so does the risk of each tornado. Furthermore, emerging evidence suggests that ongoing global warming is likely to cause more frequent and more violent tornadoes across the United States.
Although most tornadoes happen East of the Rocky Mountains, tornadoes have been recorded in nearly every state, except for Alaska. A risk of a damaging tornado is thus ever-present throughout the US. Tornadoes also pose great threat to life and property outside the United States and are known to occur in many areas, around the world, including densely populated areas, of India and Europe. Tornadoes are also common in southern Canada, throughout south-central and eastern Asia, east-central South America, Southern Africa, northwestern and southeast Europe, Italy, western and southeastern Australia, and New Zealand.
Tornadoes are capable of wind speeds of 250 mph or more and damaging paths of over a mile wide and 50 miles long. Such a tornado is likely to cause great damage to buildings and farmland, even if it were to happen over a sparsely populated territory. However, tornadoes are just as likely to occur over a densely-populated multi-million city as they are over the desert plains. If the tornado, such as the one described above made a mile-wide, 50-mile long path over a major city, the destruction of human life and infrastructure would be far more catastrophic than from the worst of hurricanes. Hurricanes can be predicted in advance. Preparations and evacuations for hurricanes can be made ahead of time. The nature of tornadoes does not allow for dryboarding of glass windows. Tornadoes are swift, unexpected, and deadly.
In recent decades, major scientific advances, such as Doppler radar helped scientists to identify, and in some cases even predict a tornado. However, the identification of an ongoing twister, or prediction of its appearance, minutes before the touchdown of the deadly funnel, does little to alleviate the danger posed by the tornado. At best, it may allow people, who are at home to hide in their shelters. However, the instant warning of an ongoing storm is unlikely to reach people who have their radios and TVs turned off. Even if people learn of the threat, it may already be too later, or there may not be a proper shelter nearby. And other than hiding in the shelter, if such a shelter exists at all, there is little that can be done by individuals or the government against a raging tornado.
The exact mechanics of tornado creation are still not fully understood. Several theories exist as to why and how these storms occur and are sustained for such long periods of time. In the absence of clear understanding of all the details of the phenomenon, the prior art offers few, if any solutions that would allow to actively prevent or interrupt a twister. Thus, if a major tornado, was heading toward a large city or a sensitive installation, such as a chemical stockpile, all a government could do is issue warnings, passively monitor the events and hope for the best.
Although major theories of tornado formation offer somewhat different interpretations of the details of storm's mechanism, they all agree on the major conditions required for a tornado to form. The most important condition is the collision of the warm and cold air. Thus uniformly warm or uniformly cold climates have few tornadoes, while areas like southeastern US, where warm air from the Caribbean and cool air from Canada collide, see the greatest number of tornadoes. Generally accepted theories of tornado formation state that it is the interaction of the warm and cold air that creates the driving force for a tornado.
In the United States, for example, the warm moist air, just above the ground coming from the Gulf and/or heated by the surface of the earth has a general upward motion. At the same time the cold dry Arctic air brought in by the cold fronts has a general downward motion. These upward and downward motions of the fronts accelerate tremendously in each other's presence, with warm air streaming upwards at great speed and cold air falling down. Naturally, this rapid redistribution of air masses is accompanied by violent winds and lightning. As warm moist air is rapidly cooled, voluminous precipitation, often in the form of large hail, bombards the ground. Initially, this interaction of rising warm air and falling cold air may create a horizontal spinning effect in lower atmosphere. According to the theory of tornado formation set forth in the National Weather Service Tornado Preparedness Guide, rising air within the thunderstorm updraft may tilt the rotating air from horizontal to vertical, creating a rotating wall cloud, which, upon touchdown with earth becomes a tornado.
It is suspected that in many types of tornadoes (or tornado-like storms), touchdown with the earth begins when increasing rainfall drags with it an area of quickly descending air, known as rear flank downdraft (RFD). This RFD drags the rotating air toward ground with it. This rotating air often takes the form of a visible funnel as it approaches the ground, and as the winds kick up dust and debris that are pulled into the funnel. It is now a full-blown tornado.
Initially, the tornado has a good source of warm moist inflow to power it. The areas of such inflow can be observed by doppler radar and can otherwise be recognized by meteorologists. As long as such an inflow exists, the tornado can, sustain itself, and even grow and continue its destructive path. This destructive phase can last for minutes or hours.
While the tornado rages on the ground, the RFD becomes an area of cool surface winds. As this area of cool air expands around the tornado, it eventually cuts off the inflow of warm moist air that powers the tornado. Warm air feeds the tornado, much like oxygen feeds fire in a stove. Once the supply of warm air is interrupted, or once the tornado “sucks in” the cool air brought down by RFD instead of the warm air, the system begins to “choke.” The tornado rapidly loses power, and often becomes thin and rope-like. As tornado begins to dissipate, as its rotation is interrupted, so is the rotation of the mesocyclone, associated with the tornado. Once the tornado dies off, its mesocyclone often disappears, or is greatly weakened.
This cycle of cold-warm air interaction, or variations thereof, are generally associated with most tornadoes and tornado-like circulations, and certainly the most powerful tornados. Many fine details of tornado life cycle and formation still remain a mystery, though.
There is a reason why to this day tornadoes and tornado-like storms remain some of the least understood natural phenomenons. The collision of warm and cold fronts, by itself is not sufficient to bring about the destructive powers of a twister. In most cases, such a collision creates rains and thunderstorms, nothing more. Only in very rare cases do tornadoes occur out of thunderstorms. The creation and sustainment of a tornado, requires precise interrelation of a multitude of factors and mechanisms, many of which are still not fully understood by science. Most likely, in different types of tornadoes (multiple-vortex, satellite, waterspout, landspout, etc.) and tornado-like circulations, somewhat different factors and mechanisms are at play. But it is clear that the violent powers of a tornado are borne out of an equilibrium, a delicate balance of forces of nature that come together at the same time, in exact proportions required to sustain a twister.
The complexity of interrelation of all the factors required for a tornado explains why tornadoes often appear suddenly without a warning, when all of the required factors come together. It also explains the sudden disappearance of even the most powerful twisters. Tornadoes and tornado-like circulations are not stable. Instead, they are some of the most fragile natural phenomena. It must thus be possible to affect at least one of the variables of this fragile equilibrium to disrupt the beautiful and deadly force. The present invention offers one way of interrupting the deadly march of a tornado or any tornado-like circulation.
Most past inventions in the art of tornado safety mostly involve the improvements in detection, warning, and protection against the storms. The protection against tornadoes mostly involves the design of better and stronger shelters.
An attempt to mechanically reduce the destructive effects of tornados was described in one of the US patents. The invention offered an intricate machine, a special propeller, referred to as fluid dynamic converter. This propeller or propellers were intended for insertion into the rotating columns of air inside a tornado. The fluid dynamic converters were supposed to mechanically impart a rotary motion to a column of air in the direction opposite to the rotation inside a tornado. In a sense, the invention offered to counteract the force of nature with a mechanical force of a man-made machine. Assuming that such a machine may theoretically be effective against some tornados, the size, power and costs of the machine required to achieve any effect against a full-blown tornado, as well as the difficulties associated with the instant availability of such machines in the area of the storm, combined with the transport and safety issues associated with transporting such a machine into and out of the tornado, make this approach far less than ideal.
However, total lack of any options for action in response to a tornado, combined with unreliable prediction and warning, is an even worse approach. Today, there is nothing that any government can do in response to a tornado that rages for hours and is moving toward a chemical factory, or a densely-populated city, threatening millions of lives. Therefore, a method of actively counteracting, or “extinguishing” tornadoes is required in the art. Such a method must be applicable to a broad range of tornadoes and tornado-like storms and be implementable on short notice in locations prone to the threat. The method must not be excessively expensive or dangerous to carry out. The method of present invention achieves all of these objectives and provides various additional benefits.