UAE tries cloud seeding to induce rain
Abu Dhabi - With water scarcity predicted to reach alarming levels by 2025 in the Middle East, Gulf Cooperation Council (GCC) governments are seeking additional research into ways to reverse damage caused by climate change. In addition to building dams and reservoirs, desalinating sea water and recycling waste water, the oil-rich United Arab Emirates is “inseminating” clouds passing over the desert nation to produce rain.
The technique known as “cloud seeding” is a form of weather modification that attempts to change the amount or type of precipitation by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter microphysical processes within the cloud.
“We do not want to waste a single drop of water,” said Abdullah al-Mandoos, executive director of the UAE’s National Centre of Meteorology and Seismology. Population growth and rapid urbanisation in Gulf Arab countries is expected to increase pressure on already scarce water resources.
Cloud-seeding missions in the UAE are carried out by a fleet of four Beechcraft King Air C90 aircraft, stationed at Al Ain International Airport, ready to fly at short notice. The planes are armed with salt flares that are fired into promising clouds to increase condensation to trigger a downpour.
Abu Dhabi-based forecasters monitor weather radar to tell pilots when to attempt rainfall-inducing sorties. “As soon as they see some convective cloud formations, they launch us on a flight to investigate” to try “to seed the cloud”, explained Mark Newman, deputy chief pilot at NCMS.
Newman said summer is usually the busiest season, when clouds form over the eastern Al-Hajar mountains, which deflect warm winds blowing from the Gulf of Oman.
The strength of the updraft determines the number of flares fired as the plane explores the base of the forming cloud. “If we’ve got a mild updraft, we usually burn one or two flares. If we’ve got a good updraft, we burn four, sometimes six flares into the cloud,” Newman said.
Not all seeded clouds produce rainfall but it happens often, he said, adding: “It is fantastic… As soon as there is rain, there is a lot of excitement. We can hear the guys in the office are happy.”
The UAE, an oil-rich federation of about 8 million people, ranks among the world’s ten driest countries. Its annual rainfall is 78 millimetres, more than 15 times less than what falls in an average year in the United Kingdom.
The NCMS runs the cloud seeding programme to increase annual precipitation, although the effectiveness of the technique has often been questioned. However, US ski resorts in Colorado reportedly use the method to induce heavier snowfall. China used rain dispersal technology to ensure dry weather during the opening of the 2008 Beijing Olympics.
To cover surging water needs, driven by rapid economic growth and an influx of foreigners, the UAE has resorted mainly to desalination. The country accounts for 14% of the world’s desalinated water and is the second largest producer, after neighbouring Saudi Arabia.
The country has 33 desalination plants, which provide 42% of its needs, according to a 2013 report by the environment and water ministry. Groundwater represents 44% of used water, putting immense pressure on the country’s reserves. Another 14% of water usage comes from treated waste water, mostly for irrigation and landscaped green areas.
Rain triggered through cloud seeding is much cheaper than desalinated water, according to Omar al- Yazeedi, head of research at NCMS.
In 2010, four days of heavy rain induced by cloud seeding brought downpours equivalent to the nine-year output of a single desalination plant in Abu Dhabi, he said.
“This shows that there is a huge amount of water that could be tapped,” he said. “It is a source that cannot be ignored.”
Studies indicate that cloud seeding can increase the amount of rain 5-70%, depending on the quality of the clouds, Yazeedi noted.
The American Meteorological Society said in 2010 that, despite uncertainty over its effectiveness, “large potential benefits can warrant relatively small investments to conduct operational cloud seeding”.
The UAE is also looking into methods to preserve rain that does hit the ground, instead of allowing it to quickly evaporate or flow into the sea. It has built dams and reservoirs to gather water that flood desert wadis.
The country has around 130 dams and levees with a storage capacity of about 120 million cubic metres, according to a ministry report.
Mandoos said studies were being prepared to plan more dams and to protect water, aimed at directing rain “from the cloud right into the aquifer”.
While water resources are in short supply and demand for water is growing in GCC countries, the question of the optimal management of water resources is of crucial importance, with implications not only for the future development of the countries but also for the sustainability of their past economic and social achievements
Cloud seeding could be one of the options to reverse water scarcity and desertification. For many scientists, cloud seeding is no longer considered a fringe science but rather a mainstream tool to improve precipitation.
New technology and research have produced reliable results that make cloud seeding a dependable and affordable water-supply practice for many regions and a much cheaper procedure than desalination.