(Natural News) Chinese researchers found an effective weather modification method to bring greater levels of rainfall. The method works by firing low-frequency sound waves at clouds to vibrate water droplets and increase the likelihood of them merging into larger droplets.
In a paper published in the journal Science China Technological Sciences, the researchers reported that the method can increase the amount of rainfall by up to 17 percent. They noted that the technology still needs refinement but hopes it will help increase the amount of rainfall in drought-prone areas.
But critics are concerned that the method is scientifically unfounded and generates noise pollution.
Producing artificial rainfall via sound waves
China has about 22 trillion tons of atmospheric water vapor, but only 20 percent of this reaches the ground every year. The western regions are particularly affected, as they typically receive smaller amounts of rain than the national average.
To that end, the researchers tried to trigger rain by blasting low-frequency sound waves from a sound generator. The sound generator is powered by a diesel engine and is capable of compressing air to several times the atmospheric pressure at sea level.
The researchers tested the device in the Tibetan Plateau to produce sound waves with a frequency of about 50 hertz, which is barely perceptible to the human ear, and a volume of up to 160 decibels (dB), which is as loud as a jet engine running at full speed. The sound waves had a volume at 160 dB at sea level but by the time they reached the clouds, the volume dropped to 30 dB due to reduced pressure.
Using radar signals to measure the water droplets inside the clouds before and after firing the device, the researchers found that the sound waves produced significantly more water droplets and increased rainfall by between 11 and 17 percent within a radius of 1,600 feet from the sound generator.
This increase, according to the researchers, is caused by smaller particles oscillating and merging into larger ones, which then become heavy enough to come down as rainfall.