In the world’s drying countries, unique solutions are often required to subsidize for the lack of rainfall that occurs. Countries such as UAE have turned to a unique solution called “cloud-seeding” to help capture every drop of rain possible from the clouds that pass over. King Air aircraft play a vital role in jump starting the process.
The UAE’s National Centre of Meteorology and Seismology (NCMS) run the cloud seeding program out of Al-Ain airport. The centre’s forecasters monitor weather radars for clouds that could be possible candidates for the process.
“As soon as they see some convective cloud formations, they launch us on a flight to investigate (to try) to seed the cloud,” said Mark Newman, deputy chief pilot at NCMS told news agency AFP.
A typical cloud-seeding operation consists of injecting a microscopic material such as salt into clouds either from aircraft or land-based stations on mountaintops where updrafts carry the material into passing clouds. Water vapor immediately condenses on these microscopic seeds as ice crystals. The crystals increase in size until they become large enough to overcome the forces of “uplift” in the cloud and fall as rain, snow or hail.
The NCMS program has a fleet of four Beechcraft Air C90 aircraft based at the site which are equipped with salt flares. The planes fly most often during the summer, when clouds form over the local eastern Al-Hajar mountains. These clouds deflect the warm wind blowing from the Gulf of Oman. The strength of the updraft correlates to the number of flares the plane will fire as it explores the base of the forming cloud.
“If we’ve got a mild updraft, we usually burn one or two flares. If we’ve got a good updraft, we burn four, sometimes six flares, into the cloud.” said Newman.
According to Newman, not all seeded clouds will produce rainfall, but it does happen often.
“It is fantastic, as soon as there is rain there is a lot of excitement. We can hear the guys (over comms) in the office are happy,” said Newman.
A myriad of arguments exist for the viability of cloud seeding. In 2004 the United States National Research Council released a report stating that to date, there is still no convincing scientific proof of the efficacy of intentional weather modification as it only has 30% or less chance of success. However, studies have also found statistical evidence for seasonal precipitation increases of about 10% with winter seeding. In 2010, The American Meteorological Society said despite some uncertainty over its effectiveness, “large potential benefits can warrant relatively small investments to conduct operational cloud seeding”.
There is no doubt that NCMS puts faith in the program though. Desert countries rely on desalination plants for water resources. Omar Al-Yazeedi, head of research at NCMS, noted that rain triggered through cloud seeding is much cheaper than desalinated water. In fact, in 2010, four days of heavy rain induced by cloud seeding brought downpours equivalent to the nine-year output of a single desalination plant in Abu Dhabi.
“This shows that there is a huge amount of water that could be tapped. It is a source that cannot be ignored,” said Al-Yazeedi.