Making rain while the sun shines

Climate change over the past two decades has caused a drastic drop in rainfall, leading to prolonged dry spells in the kingdom, according to a recent study by the country’s water ministry.
The available water resources in Jordan offer 800-900 million cubic metres of water annually, which is enough for about three million people. But, as Jordan’s population continues to expand, it now has more than 10 million water users.
This year, Jordan’s 10 major dams were left at just 59% capacity after the wet season.
It has been predicted that Jordan will witness a 15-60% decrease in precipitation and a 1-4°C increase in temperatures over the next few years, according to the 2013-2020 Jordan climate change policy. There will be a corresponding impact on the country’s natural ecosystems, river basins, watersheds and biodiversity.
Artificial rain-making is, thus, of great interest to Jordan, though early experiments conducted between 1989 and 1995 were unsatisfactory.
More recently, on March 23 this year, Jordan and Thailand signed a memorandum of understanding allowing Jordan to benefit from Thailand’s rain-making experience.
Thailand’s current rain-making technology was developed by King Bhumibol Adulyadej in 1969, and relies on introducing chemicals in cloudy areas to ‘seed’ the clouds in a way that then promotes precipitation.
Two basic groups of chemicals are used depending on whether a cloud is cold or warm. These chemicals are generally environmentally friendly materials, including calcium chloride, compressed carbon dioxide dry ice, silver iodide, salt powder and a compound of urea and ammonium nitrate.
The Jordan Meteorological Department (JMD) sent a team of six meteorologists, a pilot and an engineer from the Royal Jordanian Air Force, to participate in artificial rain-making operations in Thailand and to learn the techniques used.
In March, the JMD carried out an initial rain-making experiment over the catchment area of the King Talal Dam, in northern Jordan and, after the visit to Thailand, conducted another rain-making attempt in August 2016.