China plays rainmaker with modified drone flights

While most countries have backed away from weather modification, China has embraced the concept and is stepping up efforts to create rain on demand. The China Meteorological Administration’s first purpose-built weather modification drone, the Ganlin-1, made its first flight last week.

Ganlin, which means “sweet rain”, is part of a project launched in March 2019 to increase rain and snow in the Qilian mountains region, which has suffered from repeated droughts. Ganlin is a modified version of the Wing Loong II flown by China’s military and has a wingspan of about 20 metres and a flight endurance of more than 14 hours. Its 5,000-kilometre (3,000) range is enough to traverse the entire region and it is much less expensive to operate than crewed aircraft. Previously the Chinese have used aircraft and rockets to launch rainmaking payloads – usually powdered silver iodide – into the clouds.

Ganlin carries a variety of weather sensors as well as a payload of rain-seeding catalyst. The developers claim it can identify the optimal area for cloud seeding, release the catalyst and measure the effects afterwards.

Previous rain-making programmes have suffered from lack of statistical evidence: it is difficult to tell whether it would have rained anyway. China’s cloud seeding operations with Ganlin drones may provide more data and settle the debate for good.