x Abu Dhabi, UAEWednesday 26 July 2017

Cloud seeding effort adds extra pilot and new hangar

The UAE has been experimenting with artificial means of inducing rain since 1999, with measurable results.

The UAE's cloud seeding programme is expanding, with plans to hire a fourth pilot and build a new hangar for its airplanes at Al Ain International Airport. Work on the facility could begin as early as August, said a representative for the National Centre for Meteorology and Seismology, which is running the programme. Prompted by a shortage of natural water resources, the Government began funding cloud seeding research in 1999.

The country's cloud seeding programme has two planes, twin-propeller King Air C90 aircraft, at its disposal. Although they have been kept outdoors, they carry sensitive equipment and need to be protected from the sun. The programme has three pilots and runs flights mostly in the eastern part of the country, where conditions are the most favourable. The process involves sending planes up to study the chemical composition of the local skies and disperse chemicals into certain clouds in an attempt to produce rain. The latest experiment was carried out Saturday, 50km north of Al Ain, said a scientist at the centre.

"The plane took off at 4pm," he said. "There was 0.6 millimetres of rain in Um Ghafah and moderate rain close to Jebel Hafeet." The planes release a mixture containing various salts - potassium chloride, sodium chloride, and a small amount of magnesium - into clouds at an altitude of 2,438 metres. As the salts are released they attract moisture in the cloud. The droplets swell and eventually become so heavy that they fall in the form of rain.

To produce rain, the scientists need what are known as convective clouds, which are produced from warm air pockets rising from the surface and are rarely found in the winter months. Such movement allows chemicals released at the base of the clouds to disperse upward. In the summer, most air coming from Oman forms into suitable clouds over the Hajar Mountains. Between July and September, such clouds form about four days a week, the scientist said. As the cloud formations are small, with a radius of between five and 15 kilometres, the rainfall is localised. When the water falls over the rocky mountains, it quickly seeps underground.

"It is done mainly to recharge the underground aquifers," the representative said. About 40 countries carry out such experiments. In November last year, Chinese scientists were embarrassed after an experiment designed to alleviate a drought over Beijing produced snow instead. While proponents say cloud seeding could be a solution for arid countries such as the UAE, not everyone is convinced. The technology has yet to deliver results on a large scale, and there is also potential for pollution, said the scientist.

"Sodium chloride is not a simple compound," he said. "It is salt. This country is suffering from high salinity of the soil and groundwater." @Email:vtodorova@thenational.ae