The UAE's National Center of Meteorology is conducting tests to see whether electricity can be used during cloud-seeding operations to enhance rainfall over the country, and mitigate water stress in arid regions.
Alya Al Mazroui, Director of the UAE Research Program for Rain Enhancement Science (UAEREP), explained to Gulf News how clouds could be given a helpful jolt of electric charge to increase much-needed rainfall in the country.
"With the help of Unmanned Arial Vehicles (UAVs), the UAE's NCM along with a team of national and international experts are conducting research to test the effectiveness of delivering electric charge into clouds to improve rainfall," she said.
"The UAE is conducting this campaign with the support of experts from the NCM, UAEREP and several national and international research and academic organisations including the University of Reading and University of Bath in the United Kingdom. The campaign is led by Giles Harrison, Professor of Atmospheric Physics at the University of Reading in the United Kingdom and a second cycle program awardee," Al Mazroui added.
The study is based on an award-winning research proposal by scientists at the University of Reading in 2017.
How does it work?
She explained: "We are using UAVs or drones to conduct these experiments in the UAE. The UAVs are equipped with a payload of electric charge emission instruments and customized sensors. These drones will fly at low altitudes and deliver an electric charge to air molecules."
The study investigates how charge modifies the growth of tiny water droplets into larger drops that fall as rain. As clouds naturally carry positive and negative charges, altering the size of the charges could cause the water droplets to grow and merge, thus producing rain.
"The UAVs fly at low altitudes around a meteorological mast instrumented with an electric field mill. Charge is emitted by the UAV and detected at the surface by the electric field mill," according to the UAEREP.
The UAVs were developed and tested in the UK, Findland and the UAE.
According to UAEREP, the effectiveness is tested on clear air days, and once conditions permit, on days with light fog with the presence of dust particles in the atmosphere, which is expected to lead to more highly charged conditions.
Since the use of drones needs specific permissions and space, the experiments are taking place at SANAD Academy, a flight school in Dubai.
How is it different from traditional cloud-seeding?
The charge emission technology uses a small, lightweight vehicle to deliver charge into the clouds instead of traditional cloud seeding payloads. This method does not involve the emission of any solid particles into clouds such as silver iodide or salt.
During traditional cloud seeding flights in the UAE, natural salts or hydroscopic agents are shot into clouds to enhance rainfall, Alya Al Mazroui explained.
The NCM’s cloud seeding department uses a sophisticated weather surveillance radar (WSR), which monitors the atmospheric pressure around the clock.
The NCM first gathers required information through weather satellites, pictures and the WSR
Cloud seeding missions are only dispatched if rain-bearing cumulus cloud formations are seen over the country. Once they are identified, the NCM quickly launches aircrafts carrying salt crystals – mixed with magnesium, sodium chloride and potassium chloride.
Reaching over the clouds, the pilots shoot the flares that inject the salts in the upper coldest portion of the clouds. The process helps develop water droplets that gradually grow in size by colliding with each other and that’s what the scientists called the coalescence. These droplets then start dropping and form the rain.
What is cloud seeding?
However, with the charge emission technology method, no solid particles are shot into the clouds. Instead, the UAV emits positively and negatively charged ions, which will attach to cloud droplets and aerosol or dust particles which are already present in the atmosphere. "Charge is expected to modify the behaviour of droplets and particles (such as helping droplets grow), which in turn may influence rainfall processes," according to the UAEREP.
"The other aspect which is different is the platform used to deliver the charge: the use of UAVs provides a cost effective and flexible method of delivering charge to cloud layer altitudes. The nature of charge emission technology means that a small and lightweight platform can be used, unlike traditional cloud seeding payloads which require much larger aircraft," an official added.
UAE: A global hub for rain enhancement research
Commenting on the importance of the research, Alya Al Mazroui said: “...we seek to ensure that their projects are geared towards addressing the challenges facing water security in arid regions. Through our partnerships with prominent scientists and research institutions across the globe, the program is accelerating the development of practical innovative solutions in the field of rain enhancement science.”
Dr Abdulla Al Mandous, Director of the National Center of Meteorology (NCM) and President of the Regional Association II (Asia), said: “The NCM and the UAE Research Program for Rain Enhancement Science are continuing to support the awardee projects to contribute to the development of viable solutions for the growing global water stress. Such efforts are crucial in driving and encouraging innovation in applied scientific research to advance global rain enhancement capacity. With the continued support of our wise leadership, NCM is committed to mitigating the risk of water stress on arid and semi-arid regions around the world, while enhancing the country’s status as global hub for rain enhancement research.”
