Control of hurricane

Hurricanes and typhoons these strong tropical storm can artificially control its path and intensity of the road?

Every year, the powerful storm rotation taking more than 120 km per hour winds, swept across the tropical oceans and the invasion coast, often along with the damage caused by the broad masses of the area. These rotating storms called typhoons in the western Pacific, the Atlantic and eastern Pacific Ocean known as the hurricane, and in the Indian Ocean are called cyclones, when they hit densely populated areas, may cause thousands of people died and billions of dollars property damage, but nothing can completely stop them. 

 Are we on these terrible forces of nature are really helpless Forever? I do not and research partners think so. Our research team is exploring how the hurricane is not over to the more dangerous path, or weakening of their strength. Though it is difficult to achieve this ambitious goal is likely to take decades, but our results show that will now proceed to study the possibility, not a bit too early. 

 Once considered to control the hurricane, the researchers must be very accurately predict its path, and to identify the hurricane will affect the behavior of the physical changes (such as temperature changes), but also know how to produce these changes. Although this study has just started, but over the past few years by the successful implementation of computer simulation of the hurricane, we can see that regulation should be implemented in the next hurricane. In addition, the difficulties caused by a variety of weather factors - the atmosphere of the extreme sensitivity of micro-stimulation may be that we tried to control the key to the hurricane. For example, the beginning of our research on the use of small changes in the hurricane's initial state to change the path of the hurricane, this attempt was very successful, the follow-up studies are quite smooth.

To understand the hurricanes and typhoons are vulnerable to severe tropical storm on the impact of human intervention, it must understand their nature and origin proceed. Hurricanes (typhoons likewise) is born in the tropical seas Mission. Low-latitude oceans continue to provide heat and water vapor to the atmosphere, resulting in the sea above the warm and humid air. When these air rise, water vapor will be the formation of cloud condensation or precipitation. Condensation releases heat, which is the first heat in ocean surface water, evaporated when the amount of solar energy absorbed. This so-called "latent heat of condensation" release, making the air to increase buoyancy, through this self-reinforcing feedback process and continue to rise. Finally, the tropical low pressure will begin to organize and strengthen, the formation of our well-known "eye" (no wind, the center of the hurricane will be around its rotation). When hurricanes come into contact with the land when the supplementary source of warm water have been cut off, and thus its strength weakened rapidly. 

 Yu Wind Dreams 

 Because of the hurricane most of the energy from the sea air condenses into Cloud Shui release of latent heat, so the Giants hope to tame the stubborn pioneer researchers, will focus on using technology to change raining process of condensation, which is at the time to influence weather phenomena only viable approach. Early 1960s, the U.S. government to appoint a "wind-breaking program," the scientific advisory group, engaged in a series of brave (or perhaps that is foolhardy) experiment to clarify whether the method could be feasible. 

 "Wind-breaking program," team's goal is to slow down the development of hurricanes, the methodology is to use technology to increase rain eye wall (around the eye of the high-speed ring cloud area) outside the first rain bands of precipitation. Their use of aircraft for the hurricane within the highest, coldest Department voted sprinkling silver iodide, which scatter in all directions of the particulate matter, it should be done as a result of increased movement of water vapor cooling in the freezing process needs condensation nuclei. If everything all as expected, clouds will grow rapidly, consumed off the supply of warm moist air, which replaced the previous eyewall. Through this process, the radius of the eye will become larger, thereby weakening the strength of hurricanes, this method is similar to the ice-skating spin, they will be open in order to reduce the speed of the arm in general.

The result of "wind-breaking program" has not been clear conclusions, now meteorologists do not believe that this method of hurricanewill be effective because the turmoil in the gas content of supercooled water scarcity, with the previous views to the contrary.

Chaotic weather 

 Our current research stems from my 30 years ago in an intuitive, when I was learning postgraduate Chaos Theory. Chaotic system is a seemingly random act, but in fact has been a standardized system, it also particularly sensitive to initial conditions, therefore, seem insignificant in the initial conditions of random changes, they will probably have a profound impact, but quickly lead to unpredictable results. The hurricane, the tiny differences in the water, such as temperature, large-scale flow of the location (it can guide the turmoil road), and even around the eye of the storm clouds spin characteristics of shape, etc., can strongly influence the path of the hurricane may and power. 

 Small role in this atmosphere of extreme sensitivity, coupled with small errors in weather prediction models will be rapidly increasing features, is caused by long-term (more than five days) the reasons for forecasting very difficult. But such sensitivity to let my curiosity, deliberately added to the hurricane on the small initial differences, whether it can produce powerful enough to affect the effectiveness of the hurricane, whether it is manifested in the hurricane away from densely populated areas, or to reduce its speed. 

 In those days, I can not continue to explore these ideas. However, in the past 10 years, numerical simulation and remote sensing technology has made significant progress, so that I can re-enter I am interested in large-scale weather-control study. In by the U.S. Department aerospace advanced funds to support the concept of the Institute, I and Atmospheric and Environmental Research Inc. (AER) of the national advisory body of the R & D colleagues, hoping to make use of complex computer models of hurricane to find out may eventually approach the practical application. In particular, we use weather forecasting technology, simulation of previous hurricanes, by observation of changes in hurricane simulation out to test the effectiveness of various kinds of interference.

Simulation of Chaos 

 On the prediction itself, even today the best weather forecast computer models, there are still a lot of room for improvement, but after they used a modified simulated hurricane, but very useful. These models rely on numerical methods to simulate the complexity of the development process of the hurricane, that is, when short-term and continuous step-by-step (time step) will be out to estimate the state of turmoil. Numerical Weather Prediction computing basic assumptions are: the overall quality of the atmosphere, energy, momentum and moisture, will not and will not generate eradication. Such as hurricanes in such a fluid system, which are conserved quantities of storm flow with the move, however, the system in close proximity to the border or fringe, the situation becomes more complicated, for example, in the sea, we have simulated the atmosphere may be won or lost on the four conserved quantity circumstances into account. 

 Model workers in the state of the atmosphere is defined as all physical measurements of a complete description of variables, including pressure, temperature, relative humidity and wind direction, wind speed, the physical quantity to meet the computer simulation is based on the physical nature conservation. In most of the weather patterns, these can be observed variable is defined in the atmosphere to that of three-dimensional grid, so every high degree of each character can make a graph. Model workers, all the grid collection of variables, known as the model state. 

 In the implementation of prediction, the numerical weather prediction model from a certain moment in time when a small step forward in computing model to repeat the state (time-step may be a few seconds to a few minutes, depending on the model-scale analysis of movement may be). In each time step, the pattern of the role include: a variety of changes in atmospheric wind as the nature of the process of evaporation, precipitation, surface friction as well as in important areas of long-wave radiation cooling and heating sunshine.

Unfortunately, the weather forecast is flawed. First of all, the pattern is always the initial state is neither accurate nor complete. Hurricane particularly difficult to determine the initial state, which is scarce because of direct observation and difficult to implement. However, we know from satellite cloud pictures, hurricanes have a complex and sophisticated structure, the cloud may be very useful, but we need to know more. Secondly, even if there is a perfect initial state, a strong tropical cyclone of the computer model was prone to error. For example, the state of the atmosphere only in the grid to calculate and therefore can not correctly handle the grid is less than length (two adjacent lattice spacing) characteristics of the phenomenon. If the model is not very high resolution, near the eye wall structure (the most important characteristics of the hurricane) will become moderate and details unknown. In addition, the model and its attempt to simulate the real atmosphere, like a chaotic behavior. These defects caused by error, as the forecast rapid growth of the computing process. 

 Data Assimilation 

 Despite these limitations, this technology to our goal remains very useful. We experiment to amend a forecast efficient initialization system, called the four-dimensional variational data assimilation (4DVAR) system, which refers to the fourth dimension is time. In the European Center for Medium-Range Weather Forecasts (ECMWF) the world's leading meteorological center, the daily use of this complex technology to forecast weather. In the forecast before the start, to the most effective use of all by satellites, ships, buoys and airborne instrument data collected by observation, 4DVAR these measured values, as well as the initial state of the atmosphere are based on speculation that the value of combining the first time, this process is known as data assimilation. This value is usually the first to speculate in the original observation point in time the value of the six-hour forecast. It is worth noting that, 4DVAR is present in the observation point in time into each observational data, rather than a few hours during the information together. Observational data with the first guess the value of the results of assimilation, then used to start a six-hour forecast operations. 

 In theory, the data assimilation have had to weather the state of the best estimate, models of the observations in the fitting and the first to speculate on the value of the fitting is balanced. Although this issue is clear statistical theory, but application of appropriate assumptions and it needs the information is only approximate, so the practical application of data assimilation is mixed Arts and Sciences. 

 Specifically, 4DVAR identify atmospheric state can not only meet the model formula, but also very close to the first guess value and the actual observations. It can achieve this difficult task, relying on the back section of the adjustment in the six hours at the beginning of the model of the initial state, the adjustment is in accordance with this period of time from the simulation model and observed values the difference between the amount of . In particular, 4DVAR capacity to exploit those differences to calculate the sensitivity model, which is the need to calculate how much each parameter change, will be in the mode of fitting observations have an impact on the extent. This method of calculation will use the process to the so-called conjugate model, back in time 6 hours of computing time interval, and then one of the best of the program will be selected on the mode to adjust the initial state the best way to make the closest analog value Hurricane true among six hours in this progress. 

 Because this method is the use of models to approximate the equation to adjust, so the whole process (simulation, compared to conjugate model and optimization) must be repeated to fine-tune the results. In the process is complete, six-hour simulation of the final status of the proceeds will be the next six hours the first guess value. 

 When the simulation that in the past after a hurricane, then we can change it at different times of one or more features, and view the effect of these changes. The results showed that the majority of these changes are aborted, and only with certain special features of the disturbances (self-reinforcing mechanism can trigger a special pattern or structure) will be growing enough to have a significant impact on the hurricane. To learn more about this concept, we can imagine a pair of tuning fork, a constant vibration, and the other stationary. If the two tuning to different frequencies, although the static tuning fork tuning fork by another non-stop to create the acoustic impact, it still will not follow the vibration; however if they have the same frequency, the second tuning fork will because of resonance response resonated with the former occurred. Similarly, our challenge is to find stability can produce the correct response to stimuli (that is, changes in the hurricane), so as to achieve our needs.