x Abu Dhabi, UAESaturday 22 July 2017

Cloud control: salt shot in sky to boost rain in UAE

Operations have been stepped up since the final week of Ramadan when cloud cover first appeared over the north and north-east of the country.

Heavy rain and thunder caught residents in Dubai and the Northern Emirates off guard last Sunday. Razan Alzayani / The National
Heavy rain and thunder caught residents in Dubai and the Northern Emirates off guard last Sunday. Razan Alzayani / The National

DUBAI // Weather experts have taken to the skies dozens of times this week as part of a project to increase rainfall.

Work stepped up in the final week of Ramadan after cloud cover appeared over the north and north-east of the country.

The cloud-seeding project aims to boost rainfall and replenish depleted groundwater stocks. Salt is dispersed into the clouds to help collect and retain moisture until the level of saturation cannot be contained and it rains.

Omar Alyazeedi, the head of the project at the National Centre of Meteorology and Seismology (NCMS), said cloud seeding was challenging and success was far from guaranteed.

“These cloud-seeding operations are very hard. Sometimes the temperature in the aircraft gets very high,” he said.

“Everyone has had the energy during Ramadan to continue working. We’re doing our job and trying to do our best.”

Heavy rain and thunder caught residents in Dubai and the Northern Emirates off guard this week,  with the unseasonal weather lasting three days.

But without proper scientific verification, it was impossible to say whether it would have rained without the cloud seeding.

“We cannot say that the NCMS was responsible for all the rain this week,” Mr Alyazeedi said. “Until now, there’s no technology to prove that this rain was due to us only, and without us it wouldn’t rain.

“Maybe if I didn’t seed it, it would still rain. Maybe it wouldn’t rain. We don’t know. The science is proven, but there’s no way we can verify our efforts.”

This problem has dogged the development of cloud seeding for more than 50 years.

But scientists at the National Centre for Atmospheric Research (NCAR) in the United States are developing a supercomputer-based model to accurately tell, based on all available variables, whether the likelihood of rain was augmented or rain was caused by cloud seeding at all.

Mr Alyazeedi said it would help end the debate once and for all.

“This may be the future in cloud-seeding verification,” he said. “These things are tied to research and not to a specific time schedule.

“However, I am sure within the next year it will be commercially available. We will be able to purchase it and set it up.”

Cloud seeding works by firing salt particles into a rain cloud from a plane. The particles act as “seeds”, around which water coalesces into raindrops. This can increase the chances of it raining by up to 20 per cent.

The NCMS is working closely with NCAR in developing an alternative seed particle to salt. The particle, likely to be made using nanotechnology, would mimic the exact crystal shape of ice particles, which are the natural seeds in clouds around which raindrops form.

“If we engineer it as exactly the same as the ice crystal, it will give better results. It will give more rain,” Mr Alyazeedi said. “People have been using the same materials for 60 years.

“If you end up making new materials, you will be able to take this science to the next level.”

The project has challenges, not least because it is a shared research initiative, and there needs to be clear lines on who has ownership of the final technology.

Similarly, it would involve participation from several different partners.

“You need many laboratories and they are scattered across the world,” Mr Alyazeedi said.

“It’s very hard to gather all these people from different research centres or companies and to work in one unified team. Everyone has their own agenda, so it’s very difficult.

“It’s not like agriculture, where they can engineer new tomatoes or cucumbers in a small laboratory. Our laboratory is the atmosphere. It’s huge and it’s very challenging.”

mcroucher@thenational.ae