Spring 2017, Dubai
The rumour is that lately our government has been seeding clouds so that rain is made and inclement weather is created for us living in Dubai to delight in. But the reality is that this is no rumour. Cloud seeding is happening with greater frequency and our skies are opening up with very welcome rainfall.
Cloud seeding and other weather-modification schemes have been around for years. In winter and spring (as it is now in Dubai) there aren’t sufficient ice crystals in rain clouds to give us precipitation, and if droplets fall in liquid form they generally evaporate anyway. Cloud seeding is the idea of adding ice-forming particles into the atmosphere (and clouds) to make liquid drops big enough to fall to Earth.
Some background: rainfall occurs when supercooled droplets of water – those that are still liquid but are at a temperature below the usual freezing point of zero centigrade – form ice crystals. Now too heavy to remain suspend in the air, these then fall, often melting on their way down to form rain.
Even in dry areas like Dubai, the air usually contains some water. This can be made to come together and form ice crystals by seeding the atmosphere with chemicals such as silver iodide or dry ice.
They work to promote rainfall by inducing nucleation – what little water is in the air condenses around the newly introduced particles and crystallizes to form ice. (That is, water vapor freezing onto particles, which leads to precipitation).
The ‘seeds’ (which are cigarette shaped) can be delivered by plane or simply by spraying from the ground. Whether the rains and storms we’ve been experiencing this entire week are due to cloud seeding we don’t actually know. All we do know is that its been raining off and off for the past week and the sky is filled with rolling clouds, our roads are flooded, Dubai International Airport is chaotic, and the thunder and lightening is much greater at night, and our city seems almost gothic these days…