Fine dust concentrations have risen to alarming levels in South Korea over the past few days.
One of the methods identified as a potential way to mitigate its worst effects is cloud seeding.
Tests are already being carried out in the skies above South Korea.
Our Cha Sang-mi tells us how it works and how effective it could be.
In a bid to tackle rising levels of fine dust in the country,... the South Korean government has turned to creating artificial rain.
Known as cloud seeding,... the method involves aircraft loaded with canisters full of chemical substances, such as silver iodide,... which are dispersed into the air.
Upward winds carry the substance into the clouds,... which combine with cool moisture to form ice crystals and water droplets,... resulting in precipitation.

"We conducted our first cloud-seeding test in 1963. 42 tests were carried out between 2008 and 2017 and we also bought a weather surveillance aircraft last year to monitor the effects."

However, there are several limitations to cloud seeding,... with the method only possible under a precise set of atmospheric conditions.

"Korea's weather agency and the Environment Ministry say... that fine dust is reduced when there is over ten millimeters of rain per hour. But, so far, the Korea Meteorological Administration has seen an average of less than one millimeter of rain per hour, far short of the target."

Experts have emphasized the importance of close coordination with other countries which have tinkered with cloud seeding in the past.

"Some countries like China, already did some experiment on this and other countries did the same thing, but the first thing that we have to do as a global society, is that we need to share those results country by country so that we can have some milestone or what-to-do list to move forward."

Neil Brackin, the head of U.S.-based WMI,... a firm specialized in weather modification services,... says cloud seeding is a proven technology that's been tried and tested in the field.

"Well, what we can say is... we know in the field, cloud seeding can increase precipitation. We know in the field and through scientific research, increased precipitation will reduce pollutants such as micro dust. (cut) Now, is it going to eliminate the micro dust? No. Can this have a meaningful impact in reducing the amount of micro dust in the Korean Peninsula? Absolutely."

The government also calmed public worries concerning toxic rainfall mixed with fine dust,... saying low pressure clouds will cycle out polluted air before the fall of precipitation.
Cha Sang-mi, Arirang News.