US experts test new cloud-seeding technique in UAE

The Learjet is equipped with carefully calibrated sensors that measure clouds' microphysical properties

The UAE is getting a good number of rainy days, thanks to cloud-seeding missions. Now, a team of pilots and scientists from the US is testing a new process that can further boost rainfall in the country.

The key, they said, is in cumulus clouds - those fluffy giant balls of cotton in the sky.

American researcher Dr Paul Lawson of SPEC Incorporated - who is also the second cycle awardee of the UAE Research Programme for Rain Enhancement Science - said they are currently investigating the 'ice production' in cumulus clouds. "My team of pilots and scientists has this week began researching the ice production processes in cumulus clouds in the UAE through a series of research flights with our Learjet 35 aircraft, which is based out of Al Ain Airport," Dr Lawson said.

The Learjet is equipped with carefully calibrated sensors that measure clouds' microphysical properties. It recently reached the UAE's Al Ain Airport after a six-day flight from Boulder, Colorado, in the US, with seven stops.

Ice in the clouds

The researcher explained that within the puffy cumulus clouds, tiny ice particles are formed. And when they collide with 'large super-cooled water drops', they begin an avalanche process that freeze the surrounding supercooled drops. Then, these drops would subsequently melt as they fall from the cloud - reaching the ground as rain.

"This secondary ice production process differs from the primary ice nucleation - the process where supercooled water drops freeze when they interact with a small aerosol particle called an 'ice nucleating particle' (INP)," said Lawson.

"Several investigators have found that, generally, there are too few INPs in the atmosphere to freeze all of the supercooled drops."

Now, their research will try seeding updrafts that originate at cloud base, using water-attracting materials, such as simple salt compounds.

And they would test whether such type of seeding - called hygroscopic seeding - could facilitate the development of the large supercooled drops that are required in generating rain. Their project is entitled 'Microphysics of Convective Clouds and the Effects of Hygroscopic Seeding'.

Timely research

Producing more rain is a project that is relevant not only in the UAE, it is becoming a necessity across the world, researchers have said. In fact, securing access to clean water supply for regions threatened by water scarcity is now one of the greatest sustainability challenges of "our era".

"With the need for clean water becoming ever more imperative, rain enhancement through cloud seeding promises innovative solutions based on the most advanced science and technologies," said Dr Lawson.

As an awardee of the UAE Research Program for Rain Enhancement Science, he said he is grateful for the programme and the National Center of Meteorology (NCM).

"The programme has done much to encourage and improve international research in cloud seeding science and technologies by bringing some of the best scientific minds in the field onto a common platform where their combined research could lead to greater benefits," he said.

Zawya