UAE Pioneers Safe Rainfall Enhancement Using Novel CNST Materials

The UAE Research Program for Rain Enhancement Science (UAEREP) has been pioneering the use of core-shell NaCl-TiO2 (CNST) seeding material in its cloud seeding operations. This specific type of hygroscopic material, composed mainly of sodium chloride and a small amount of titanium dioxide, was successfully researched and implemented by UAEREP in 2017. The UAE remains the only country globally using CNST materials for cloud seeding.

Cloud seeding is a weather modification technique that enhances natural processes in clouds by adding particles to stimulate condensation and convection. This method is increasingly seen as crucial for water security in arid regions and as a tool for climate change mitigation. The concept of increasing rainfall dates back to the late 19th century, capturing the interest of scientists and engineers.

Since the 1960s, researchers have explored various seeding materials to improve rain enhancement. Recent advancements focus on hygroscopic materials like potassium chloride (KCl) and sodium chloride (NaCl), which attract atmospheric moisture to enhance precipitation. These materials are non-toxic and environmentally safe, making them ideal for weather modification efforts.

The environmental impact of cloud seeding has been extensively studied. A review by the World Meteorological Organisation (WMO) found no evidence of negative environmental effects from both hygroscopic and glaciogenic materials. This conclusion was supported by over 31 papers reviewed, along with statements from other organisations such as the Weather Modification Association (WMA) and the National Academies in the United States.

The CNST material used by UAEREP consists primarily of common salt (90 percent sodium chloride) with less than 10 percent titanium dioxide acting as a coating. This combination makes the material more reactive in rainclouds, enhancing its effectiveness across different humidity levels. Neither ingredient is classified as hazardous by U.S. or international safety regulations.

Prof. Linda Zou, a grant awardee from UAEREP and a professor at Khalifa University, led significant research using nanotechnology to develop these cloud-seeding materials. She noted that traditional cloud-seeding techniques are outdated and less effective compared to modern methods enabled by nanotechnology.

When deployed in weather modification, CNST material becomes highly diluted in rainwater produced by storms. For example, typical storms in the Arabian Peninsula generate around 1 million cubic meters of water, diluting the small amount of seeding material used to concentrations far below safe exposure limits.

Effectiveness and Environmental Safety

Prof. Zou's research demonstrated that these unique seeding materials could increase large water droplet concentration by 300 percent under conditions with 100 percent humidity compared to conventional materials. Her project has been patented worldwide as an innovative application of nanotechnology in cloud seeding.

Hygroscopic seeding effectively induces rain in drought-prone areas without posing risks to public health or the environment. By attracting moisture, these compounds provide essential resources for agriculture, water supply, and ecosystem health.

The UAE's use of CNST materials highlights its commitment to advancing rain enhancement science while ensuring environmental safety. This innovative approach not only addresses water scarcity but also contributes to broader climate change mitigation efforts.

Khoder Nashar / Hatem Mohamed

With inputs from WAM