The United Arab Emirates was flooded on Tuesday after storms dumped more than a year and a half's rain in just a few hours, submerging roads as well as the international airport in Dubai.
Neighboring Oman also saw heavy rains and floods that killed at least 20 people.
Speculation spread on social media, linking the process of cloud seeding, which involves manipulating existing clouds to stimulate rainfall, to the unprecedented rainfall. But experts say the record rainfall was likely due to climate change.
Here's what we know about the causes of record rainfall and subsequent flooding in the UAE and Oman.
What happened in the UAE and Oman?
The storm initially hit Oman on Sunday before hitting the UAE on Tuesday, causing power outages and disrupting flights. The flood submerged homes, caused traffic chaos and trapped people in their homes in Dubai.
Authorities said the UAE witnessed its heaviest rainfall on record.
The state-run WAM news agency described it as a “historic climate event” that surpassed “anything documented since data collection began in 1949.” This was before the discovery of crude oil in the energy-rich Gulf country.
By the end of Tuesday, more than 142 millimeters (5.59 inches) had submerged Dubai – home to more than three million people. Nearly 127 mm (5 in) of rain fell at Dubai International Airport, with about 76 mm (3 in) of rainfall being normal in an entire year.
According to authorities, Oman received about 230 mm (9 inches) of rain between Sunday and Wednesday. Average rainfall in the capital, Muscat, is about 100 mm (4 in) per year. Bahrain, Qatar and Saudi Arabia also witnessed rain.
What fueled the speculation that blamed cloud seeding for Dubai's rainfall?
Reports quoted meteorologists at the National Meteorological Center in the United Arab Emirates as saying that Dubai made six or seven cloud-seeding flights before the rains began. Flight tracking data analyzed by the Associated Press also showed that a plane belonging to the United Arab Emirates' cloud seeding efforts flew around the country on Monday.
Cloud seeding, which began in the 1990s, was part of the country's efforts to solve water shortages.
According to reports, the NCM on Wednesday said the sowing took place on Sunday and Monday, not Tuesday.
Omar Al-Yazidi, Deputy Director General of the National Center of Meteorology, told NBC News that the organization “did not carry out any planting operations during this event.”
“One of the basic principles of cloud seeding is that you have to target clouds in their early stage before the rain comes. If you have a severe thunderstorm situation, it's too late to do any seeding,” he added.
Rainfall is rare in the UAE and elsewhere in the Arabian Peninsula, which is typically known for its dry desert climate. Air temperatures in summer can rise to more than 50 °C (122 °F).
The UAE and Oman also lack drainage systems to handle heavy rains, and waterlogging of roads is common during rainfall.
Does climate change cause heavy rains?
Experts and officials have debunked speculation that cloud seeding caused the rains.
“If that happened with cloud seeding, they would have water all the time. You can't create rain out of thin air by itself and get 6 inches [152.4mm] “Climate change presents a huge challenge for water,” said Ryan Mau, former chief scientist at the US National Oceanic and Atmospheric Administration.
Experts say the deluge was likely caused by a natural weather system exacerbated by climate change.
Mark Howden, director of the Australian National University's Institute for Climate, Energy and Disaster Solutions, said global warming had led to “unusually” warm water in the seas around Dubai, where there was also very warm air above them.
“This increases potential evaporation rates and the ability of the atmosphere to hold that water, allowing for greater amounts of rainfall to accumulate like what we just saw in Dubai.”
According to reports, the heavy rains were the result of a slow-moving storm that moved across the Arabian Peninsula into the Gulf of Oman over several days. This storm transported abundant tropical moisture from near the equator and released it heavily over the region.
The storm also appeared in forecast models days earlier.
Susan Gray, professor of meteorology at the University of Reading, said huge tropical storms like these “are not rare events in the Middle East.” It cited a recent study analyzing nearly 100 such events in the southern Arabian Peninsula from 2000 to 2020, most of which were in March and April, including a March 2016 storm that dropped 9.4 inches (about 240 mm) on Dubai within hours. Few.
The heavy rain event witnessed in Dubai today was clearly linked to a synoptic formation that increased the potential for heavy rainfall.
A slow-moving, favorably tilted trough with a strong column of moisture transport led to record high PWAT for April: https://t.co/vL3ZAbqkIH pic.twitter.com/Opoc8B8mRP
– Tomer Burg (@burgwx) April 17, 2024
Rising global temperatures, caused by human-driven climate change, are leading to more extreme weather events around the world, including heavy rainfall, climate scientists say.
“Rainfall caused by thunderstorms, such as those experienced in the UAE in recent days, is seeing a particularly strong increase as temperatures rise. This is because,” said Diem Como, professor of climate extremes at Vrije Universiteit Amsterdam. Convection, the powerful updraft in thunderstorms, is strengthening in a warmer world.
What is cloud seeding?
Cloud seeding is a type of weather modification process that usually attempts to increase rainfall or snow.
Cloud droplets do not form spontaneously. For moisture to condense, it needs a surface to adhere to. Inside the cloud are tiny particles in the air called condensation nuclei, which provide a base for moisture to adhere to.
Cloud seeding uses aircraft and ground guns to shoot particles into clouds to create more nuclei, attracting moisture. Once enough droplets combine, they become heavy and fall to the ground as rain or snow.
Small particles such as dust and dirt often play a major role in cloud formation and precipitation by providing surfaces for moisture to condense. Silver iodide likely performs the same function. Other materials, such as dry ice, can also be used for similar purposes.
This method, which was pioneered in the 1940s, cannot produce water from a clear sky: the particles must be released into a cloud that already contains moisture for them to fall, or to fall to a greater extent than would occur naturally.
Cloud seeding remains controversial in the weather community, mostly because it is difficult to prove its effectiveness, and it is unclear what negative impact it might have.
Governments in drought-stricken regions, such as the western United States and the United Arab Emirates, have invested in techniques such as seeding in the hope of generating rain.
About 50 countries, including the United States, China, Australia, the United Arab Emirates, Germany, India, Malaysia, Russia and Mexico, use cloud seeding technology.
The U.S. Bureau of Reclamation spent $2.4 million last year on cloud seeding along the overexploited Colorado River. Utah recently increased its seeding budget tenfold.
China often uses seed for irrigation purposes. I also used it during the 2008 Olympics in Beijing to keep the skies clear.
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