This summer, temperatures in Dubai have regularly surpassed 120 degrees. That’s unusually warm, even for a city in the vast Arabian Desert. It’s dry there, too. Climate-Data.org reports that the average annual rainfall in Dubai is a mere 2.7 inches.
Dubai is one of the emirates in the United Arab Emirates. A financial center, the economy also depends heavily on tourism; the city is known for its shopping and nightlife. To no one’s surprise, for a while Dubai has been turning to cloud seeding to create rain and make the tourist experience more pleasant.
They’ve employed a few approaches. One is the plain ol’ vanilla way of spraying silver iodide or another such chemical into clouds from manned aircraft. Another is firing water-attracting salt flares from aircraft into warm cumuliform clouds. A third is to have drones send electrical charges into clouds. The idea is to shock water droplets into combing. Combined droplets might become too heavy for cloud-forming updrafts to carry, in which case they’d precipitate out as rain drops.
Unfortunately, this April the area had major flooding. Nearly a year’s worth of rain fell during a single 24-hour period. Twenty-one people died, and the rain-makers caught early blame. But were they indeed at fault?
Not necessarily. England’s University of Reading is a rain-making partner in Dubai. Professor Maarten Ambaum, a meteorologist at the University, suggests that, as scant as rainfall generally is in Dubai, deluges do happen. On his department’s webpage, he acknowledges, “This part of the world is characterised by long periods without rain and then irregular, heavy rainfall, but even so, this was a very rare rainfall event.”
With climate change, air is warmer. Warmer air holds more water, creating more clouds. According to a study published in the November 2021 issues of Atmospheric Research, over the 21-year period of February 2000 – December 2020, there were enough massive cloud systems over the southern Arabian Peninsula to create 95 overwhelming downpours. Not surprisingly, the recent trend is for those downpours to last increasingly long.
Professor Ambaum: “These storms appear to be the result of a mesoscale convective system [“MSC”]– a series of medium-sized thunderstorms caused by massive thunderclouds, formed as heat draws moisture up into the atmosphere. These can create large amounts of rain, and when they occur over a wide area and one after another, can lead to seriously heavy downpours. They can rapidly lead to surface water floods.”
The emerging consensus about what caused April’s flood in Dubai is that, with global warming, hundreds of individual thunderstorm clouds formed and then combined into a single storm cloud that spanned several hundred kilometers of sky.
But how do we know for sure that cloud seeding didn’t help create the massive thundercloud? How do we know for sure that cloud seeding didn’t prompt the thundercloud to release its water all at once?
Simple. The cloud seeders had not been seeding. Although not much rain falls during the winter and spring in Dubai, they are considered the desert’s “rainy months.” As Professor Ambaum explains about the weeks preceding the flood of April 2024, “There would have been no benefit to seed these clouds as they were predicted to produce substantial rain anyway.”
