Pakistan Uses Artificial Rain in Attempt To Cut Pollution Levels

Artificial rain has been used in an attempt to lower pollution levels in Lahore, Pakistan. From a report: The capital city of the eastern province of Punjab, near the Indian border, has some of the worst air quality in the world and has become extremely polluted because of a growing population of more than 13 million people. By early December, the air quality in the city had grown so bad that schools, markets and parks were closed for four days. By last weekend, the city's air quality index (AQI) had reached levels considered extremely hazardous to health. To try to reduce them, on Saturday the Punjab government used cloud seeding to create rain in 10 locations around the city using a small Cessna plane. To create the clouds, there needs to be enough moisture already present in the clouds in the lower atmosphere. In summer, common table salt mixed with water is sprayed over the cloud patches from planes. After a few hours, the mist integrates with the clouds and produces rain. In winter, the clouds are seeded using flakes of silver iodide, which can be fired from a vehicle or a plane. The practice, also known as "blueskying," has been used to induce precipitation in several countries in the Middle East, as well as China and India.

Read more of this story at Slashdot.