By filing a patent on their innovative cloud seeding material, the research team is bringing the material in the pathway for commercialization, thereby supporting Masdar Institute’s goal of bolstering the United Arab Emirates’ local intellectual property, which is a key measure of the country’s innovation drive. It also signifies a milestone towards achieving greater water security in the UAE, as rainfall enhancement via cloud seeding can potentially increase rainfall between 10% to 30%, helping to refresh groundwater reserves, boost agricultural production, and reduce the country’s heavy reliance on freshwater produced by energy-intensive seawater desalination.
Masdar Institute Professor of Chemical and Environmental Engineering, Dr. Linda Zou, is the principal investigator of this research project, and one of the first scientists in the world to explore the use of nanotechnology to enhance a cloud seeding material’s ability to produce rain.
While the field of rain enhancement – which involves stimulating clouds to produce rain – leverages cloud physics, atmosphere physics, and topographical studies, Dr. Zou and her team complement such work through their focus on the cloud seeding material itself.
“Using nanotechnology to accelerate water droplet formation on a typical cloud seeding material has never been researched before. It is a new approach that could revolutionize the development of cloud seeding materials and make them significantly more efficient and effective,” Dr. Zou remarked.
Offering a comprehensive overview of Dr. Zou’s progress, Alya Al Mazroui, Manager of the UAE Research Program for Rain Enhancement Science said: “The Program is a unique opportunity to use advanced research methods for studying atmospheric processes in arid regions, where its understanding is most important to ensure water security globally. We are convinced that Masdar Institute’s project, under Linda Zou’s supervision, will advance rain enhancement science through innovative seeding agents.”
Dr. Deon E. Terblanche, Director, Atmospheric Research and Environment Branch, World Meteorological Organization (WMO), serves as a member of the international scientific advisory committee of the UAE Rain Enhancement Program Award. He believes that the novelty of Dr. Zou’s research has great potential to drive innovation in the field of rain enhancement: “Dr. Linda Zou of the Masdar Institute is bringing a fresh and exciting contribution to the field of rainfall enhancement. Her team's research into the development of new seeding materials, taking advantage of nanotechnology, holds exciting possibilities and is followed with considerable interest,” Dr. Terblanche remarked.
Conventional cloud seeding materials are small particles such as pure salt crystals, dry ice and silver iodide. These tiny particles, which are a few microns (one-thousandth of a millimeter) in size, act as the core around which water condenses in the clouds, stimulating water droplet growth. Once the air in the cloud reaches a certain level of saturation, it can no longer hold in that moisture, and rain falls. Cloud seeding essentially mimics what naturally occurs in clouds, but enhances the process by adding particles that can stimulate and accelerate the condensation process.
Dr. Zou and her collaborators, Dr. Mustapha Jouiad, Principal Research Scientist in Mechanical and Materials Engineering Department, postdoctoral researcher Dr. Nabil El Hadri and PhD student Haoran Liang, explored ways to improve the process of condensation on a pure salt crystal by layering it with a thin coating of titanium dioxide.
The extremely thin coating measures around 50 nanometers, which is more than one thousand times thinner than a human hair. Despite the coating’s miniscule size, the titanium dioxide’s effect on the salt’s condensation efficiency is significant. Titanium dioxide is a hydrophilic photocatalyst, which means that when in contact with water vapor in the cloud, it helps to initiate and sustain the water vapor adsorption and condensation on the nanoparticle’s surface. This important property of the cloud seeding material speeds up the formation of large water droplets for rainfall.
Dr. Zou’s team found that the titanium dioxide coating improved the salt’s ability to adsorb and condense water vapor over 100 times compared to a pure salt crystal. Such an increase in condensation efficiency could improve a cloud’s ability to produce more precipitation, making rain enhancement operations more efficient and effective. The research will now move to the next stage of simulated cloud and field testing in the future.
The UAE government has recognized the potential of rain enhancement to support water security and established the UAE Research Program for Rain Enhancement Science to increase rain enhancement research in the UAE and arid and semi-arid regions across the world. Awardees of the Program’s Second Cycle grant of US$ 5 million were announced last week during Abu Dhabi Sustainability Week 2017. They include Prof. Giles Harrison of the University of Reading, Prof. Hannele Korhonen of the Finnish Meteorological Institute (FMI), and Dr. Paul Lawson of American firm Spec Inc.
Dr. Zou’s research grant covers two more years of research. During this time, her team will continue to study different design concepts and structures for cloud seeding materials inspired by nanotechnology.
Erica SolomonNews and Features Writer31 January 2017