The UAE Rain Enhancement Program (UAEREP), overseen by the National Center of Meteorology (NCM), has launched a flight campaign in Texas, USA to investigate the effect of novel cloud seeding nanomaterials on the droplet size distribution, and ultimately, the rainfall generation process. The open atmosphere airborne tests are the culmination of successful laboratory-scale experiments and modeling studies carried out over the past 4 years, as well as the tests that took place in Abu Dhabi, the UAE, last year.
The campaign is a combined effort leveraging research outcomes and capabilities from two UAEREP projects. Developed by Professor Linda Zou, a Professor at Khalifa University and one of the three awardees of the Program’s First Cycle, the innovative cloud seeding materials are being tested by Dr. Paul Lawson, Senior Research Scientist at SPEC Incorporated, USA, and one of the program’s second cycle awardees.
Prof. Linda’s project aimed to improve the effectiveness of cloud seeding technologies used to increase rain precipitation, through engineering nanostructured properties of the cloud seeding materials to help water vapor in clouds condense, a process necessary for raindrops to form. The project successfully developed and patented a customized nanomaterial composite that was shown to enhance precipitation formation during both modeling studies and lab experiments. The project also identified the required technology and procedures for cost-effective production of this material to meet actual cloud seeding mission quantity demands.
The US city was selected for the campaign due to its cleaner atmosphere, providing a better opportunity to observe the microphysical impacts of the nanomaterial in the warm portion of convective clouds, similar to those being seeded over the UAE. This will also ensure the effectiveness of the material in different atmospheric environments, in line with UAEREP’s promising plan to mass-produce the nanomaterial and propose them to operational cloud seeding programs worldwide.
Commenting on the campaign, His Excellency Dr Abdulla Al Mandous, Director of the NCM & the President of the Regional Association II in the Asia Region, said: “Our planned testing campaign articulates NCM’s continued efforts to develop innovative solutions to address the pressing global water-stress challenges. Since its inception under the patronage of His Highness Sheikh Mansour bin Zayed al Nahyan, UAE Deputy Prime Minister and Minister of Presidential Affairs, the UAE Rain Enhancement Program has developed extensive expertise in rain enhancement to ensure sustainable sources of water. At NCM, we are committed to employing the findings of our ground-breaking research projects led by renowned international scientists for the benefit of arid and semi-arid regions around the world.”
This campaign is an important part of the implementation and testing plan of the National Center of Meteorology, which consists of a titanium dioxide nanoparticle layer coated on the salt crystals. The ground-breaking project has already led to innovative hydrophilic & hygroscopic cloud seeding materials being designed and fabricated. Experimental results obtained so far through laboratory testing and analysis suggest that this material has a much higher ability to initiate condensation of water vapor and droplet growth in the clouds than the salt crystals that is currently used for rain enhancement in the UAE.
For her part, Alya Al Mazroui, Director of the UAE Rain Enhancement Program, said: “The UAE Rain Enhancement Program is proud of the contributions made by its awardees to promote new knowledge and innovation across the spectrum of rain enhancement science. As part of the program’s sustained efforts to accelerate scientist research in this vital field, we continue to provide the awardees with every possible support and facilities to test the effectiveness of their projects. Furthermore, our collaboration with international partners allows them to realize the full potentials of their research work to address the most pressing scientific issues related to rain enhancement science.”
The campaign uses a SPEC custom-designed Learjet research aircraft equipped with sophisticated cloud physics instrumentation used in various campaigns across the world. The instruments can collectively monitor the growth of fine-mode aerosols to cloud droplets and eventually mm-sized rain drops.
The campaign includes two to three flights of approximately 2 to 3 hours each, using a minimum of two flares for each cloud penetration depending on individual cloud conditions. A total of 40 flares have been dedicated for the flight campaign that will be conducted in coordination with the Texas Water District cloud seeding aircraft.
The seeding aircraft will fly under cloud base and either ignite two flares in the updraft, or fly under cloud base without releasing any seeding material. The Learjet will break to the right and proceed to penetrate the cloud approximately 500 to 1,000 feet above the cloud base to intersect the seeding plume in the updraft. A minimum of 5 clouds will be penetrated by the Learjet to obtain natural (unseeded) background conditions for comparison with the seeded clouds.