Bending Weather to Your Will
Throughout the history of humanity, people have had to adapt to changing weather and climate. When the climate became harsher, people were forced to move to areas with a milder climate, or simply settle in environments with more favourable living conditions.
With time, due to their ability to adapt to living in adverse climatic conditions and the increase in number of people, inhabiting the Earth, the humanity have spread along the planet, settling both in hot arid deserts, and cold humid northern regions. Finally, nowadays, the constant necessity to struggle with nature and protect oneself from various whims of climate, gave place to the need to take care of nature, which in its turn needs to be protected. To some extent it can be applied to weather and climate.
By the way
Climate change has prompted a new social phenomenon – climate refugees. Scientists estimate that by 2050, their number will exceed 150 million people.
The UN Intergovernmental Group of Experts has defined the regions, most sensitive in terms of climate. For instance, in India, some 30 million people are expected to leave their homes due to floods in the next 50 years. About 1/6 of Bangladesh will become not suitable for living because of mud slides. Fresh water-strapped regions, such as the Middle East, South and Southeast Asia, as well as some parts of the American continent, will face massive migration of population.
The scale of human activity has become so large, that it started affecting even the weather, especially in major industrial cities with multimillion populations. Climatologists are talking about both local and global climate change, and there is a burning question to be answered by scientists: Is the Earth’s climate likely to undergo considerable changes as a result of human activity? If yes, how to make the changes, triggered by human influence, beneficial for people? There are hosts of similar questions, especially in periods of abnormal weather: unusually strong cold or heat waves, drought or floods, caused by downpours of rain, and the like.
Scientists from around the globe have been working on devising ways to measure weather change for quite a while already. Several prototype units, built with the purpose of modifying the weather, allegedly were created as early as already during the Cold War. The sharp increase in natural disasters in certain regions has been linked to the work of these units. It is difficult to determine whether this is true, but the public opinion on the ability to alter weather has been divided. On the one hand, environmentalists are quite concerned with the idea of people being able to affect the environment, but on the other hand, the military and scientists act as ardent advocates for modernization and improvement of peoples’ lives.
Is weather control possible? In theory…
Atmospheric circulation and weather change are caused by the amount of heat coming from the sun, and the difference in temperatures among the regions, getting the highest and the lowest amount of heat. Land and sea, equatorial and polar regions heat up in a different way. This difference in temperatures is the main reason for air masses circulation. Direction and speed of air masses also depend on the Earth’s rotation and the area landscape. If people wanted to change air masses circulation for just several days, it would demand tremendous amounts of energy – millions of kilowatt-hours. That explains why the humanity is still incapable of forcing air masses to circulate and of creating cyclones and anticyclones on their volition.
Among the existing reliable means of modifying the weather is the ability to change the landscapes, above which air masses circulate. For instance, it’s possible to construct artificial water reservoirs, channels, field-protecting forest belts, and so on, thus changing the atmosphere’s physical characteristics.
By the way
American scientists, Daniel Kirk-Davidoff and Daniel Barry have modeled a situation, which could happen if thousands of wind turbines were blowing in the direction of the Atlantic. They found out that the wind speed would drop by 20 kilometres per hour, and the airflow would become wave-like. Horse Hollow Wind Energy Centre is a major wind farm in Texas with 420 wind turbines. Wind farms like this one offer good opportunities for climate modification. The only thing left is to learn to use them in the least harmful way to the planet.
…And in practice
Cloud seeding is the most common way of weather modification, used either to cause rainfalls in arid regions, or to reduce the amount of precipitation by dispersing rain clouds and melting down fog, or to suppress hail by prompting rainfall, before the water in the clouds turns into hail-stones.
The first successful scientific attempt at cloud seeding was made in 1940s by researchers from the General Electric Co.
In 1946, Vincent Schaefer, a chemist from the General Electric Co. seeded 1.5 kilogrammes of dry ice from a plane, flying over Mount Greylock. This caused snow showers in the area. Several years later, Bernard Vonnegut, an American atmospheric scientist, discovered that seeding clouds with particles of silver iodine had the same effect. By 1951, 10% of all American farmlands were watered artificially. Between 1966 and 1972, during the Vietnam War, American aviation industry constructed thousands of planes to seed chemical agents over the so-called “Ho Chi Minh trail”, planning that additional precipitation will lock the trail in mud and make it impassable for the Vietnamese troops.
Soviet meteorologists made their first attempts at improving the weather in the 1960s. At the time, specialists devised a technology for anti hail protection, which consisted in dispersing a special agent, suppressing hail, onto a particular part of a cloud using anti hail missiles. As a result, damage caused by hail was reduced by 5-7 times. Unfortunately, this method applies only to dispersing low and medium density clouds, but the thunderstorm clouds are still too powerful for meteorologists.
In 1990, specialists from the Russian State Committee on Hydrometeorology and Oversight of the Environment designed a new technology for creating favourable weather conditions. The technology was first put in action in 1995 during the large-scale celebration of the 50th anniversary of the Victory Day, and has been widely used ever since. Among the chemicals most commonly used to disperse clouds are silver iodine, liquid nitrogen, and dry ice. Dry ice – granules of carbon dioxide 2 cm long and 1-1.5 cm in diameter – is seeded from a plane over the stratus clouds (low clouds) from above several thousand metres. When in contact with a cloud, carbon dioxide crysrallises water in the cloud, the cloud cools and gradually dissolves.
Liquid nitrogen is used to disperse nimbostratus clouds (middle clouds). Cement, talc or plaster powder, which makes the ascending air heavier and thus prevents formation of thunderstorm clouds, is used to suppress cumulus clouds (high cloud). Silver iodine is used to bombard the most powerful rain clouds. Specially equipped transport planes – IL-182, AN-26, AN- 12 – are employed for cloud seeding.
There is also a method of causing rainfalls by affecting nonthunderous clouds, which consists in sprinkling them with iodine and silver compound, which provokes formation of raindrops. American specialists employ this technique in Australia, using the sophisticated Doppler radar, which measures precipitation trajectory and water density in thunder clouds.
Chinese meteorologists are now working on a different project: they are conducting experiments with artificial snow, causing the fall of precipitation by seeding clouds over Tibet, as the Himalaya glaciers are melting and there is a threat of a drought. In April 2007, Chinese scientists provoked artificial precipitation at the altitude of 4.5 kilometres in the Nagqu region in the north of Tibet. The snow was about 1 centimetre deep. To cause artificial snowfall, they used chemicals, similar to silver iodine, which is used for “rain making”.
Meteorologists have also found a means of combating avalanches. The principle behind anti avalanche techniques consists in bringing huge snow masses down gradually, part by part, without letting them achieve catastrophic dimensions. To achieve this, meteorologists monitor and map out avalanche-prone areas. Under certain conditions, avalanches are triggered with the use of snow canons.
Recently, Russian meteorologists have learned to combat tornadoes. These violent columns of air are extremely difficult to forecast, as they can be located only 10-15 minutes before they start raging. Tornadoes are formed as a result of overlapping of numerous factors, related to the atmosphere, the area surface, influence of water reservoirs and so on.
It is extremely difficult to locate a cloud with the forming tornado and dissipate it before it reaches the area it could affect. Every minute counts in this case. Therefore, scientists devised a fully automated system of locating, classifying and eliminating these clouds with missiles, laden with special chemical agents.
Currently, there are about 150 programmes on weather modification, implemented in more than 40 countries. In October 2009, Russian scientists conducted an experiment with weather in the centre of Moscow. They tried to clear the sky above the city employing electrophysical methods. For this purpose the scientists used the so-called “Chizhevsky Chandellier”, which had been developed for 12 years. Placed skyward, the installation produces a flow of ions, which affect the clouds. But the clouds are not “squeezed out” as in the case of thunder clouds dispersion: they are lifted to a certain altitude, where they stop being rain clouds. The effect was not seen immediately, but little by little the grey thunder clouds, hanging above the city, started to clear out. Two hours later, the specialists had to switch the installation off, and it instantly started to rain in the area. However, the experiment was considered successful.
At present, scientists are still unable to predict the consequences of such tampering with nature; there are still many “blind spots” in the chain of natural processes. When people try to modify the global atmospheric processes, the main cause for concern is not the scale of influence or the amount of energy it demands. The main problem is that the consequences of such influence are uncertain. When we interfere with nature, we must not upset the natural balance, even if we believe that what we are doing will improve our living conditions.
Russian text: Natalia Sokolova
