Cloud seeding may have triggered heavy UAE rainfall
Cloud seeding operations came under scrutiny in the United Arab Emirates (UAE) last week after heavy rainfall struck the desert nation and caused flooding in Dubai's largest luxury shopping mall.
Drenched UAE residents were left wondering if cloud seeding flights arranged by the national weather agency were linked to torrential rains which hit just hours later.
Last weekend's heavy downpour sent torrents of water streaming into and through Dubai Mall, the world's second largest shopping mall.
Footage on social media showed shop assistants in the tourist hotspot rushing to protect their stock as rivers of water snaked across the mall's marble floors.
What is cloud seeding and does it work?
The UAE is one of the driest countries on earth with an annual rainfall of about 120 millimetres and most of its fresh water imported or generated by desalination plants.
By comparison, South Australian outback town Coober Pedy, one Australia's driest locations, sees just 160mm of rain each year.
The UAE's National Centre for Meteorology estimates it costs around $7000 to seed a cloud.
A medium-sized cloud can carry up to 1 billion litres of water. In a country where water is scarce, that load is potentially worth up to $450,000.
Guided by satellite data, pilots in small planes go in search of cumulous clouds.
Strapped to the wings of the plane are flares which hold a chemical mixture of potassium, sodium chloride, magnesium and other materials – essentially salt.
Once below the cloud, the pilot ignites the flares. The salt attracts moisture and is designed to form droplets of water which fall to the earth.
In 2017, the UAE performed 242 cloud seeding operations.
Cloud seeding has been carried out in New South Wales, Tasmania, Victoria and Queensland since the late 1940s but scientists are unconvinced over its effectiveness and suitability in Australia.