Swiss researchers have successfully used laser pulses to create small clouds in the laboratory, a technology they say could possibly be used to create rain on demand.
After firing short pulses of infrared laser light into a chamber filled with water-saturated air at -24 degrees C, scientists observed linear clouds in the laser’s wake — similar to the jet contrails created by airplanes.
In addition, they found the volume of condensed water droplets inside the chamber increased by half.
Severe air pollution in China’s heavily industrialized east is impeding the formation of rain clouds and contributing to a drought in northern China, according to a new study. The study, which looked at rainfall and pollution patterns for the past 50 years, concluded that pollution has reduced the number of days of light rain in eastern China by 23 percent.
Atmospheric scientist Yun Qian of the U.S. Department of Energy’s Pacific Northwest National Laboratory said that the large number of aerosols in China’s polluted skies has led to the formation of rain droplets that are up to 50 percent smaller than rain droplets in clean skies. The smaller droplets do not as readily form rain clouds, which means that lighter rainfalls valuable to agriculture — ranging from a drizzle to accumulations of .4 inch per day — are occurring less frequently, according to the study, published in the Journal of Geophysical Research-Atmospheres.