The rainmaker

When Mother Nature doesn't cooperate in releasing rain from the clouds, it's up to men like Wg Cdr Maneepan Robchanachai to make it happen. He explains how it is done to Life reporter Pattramon Sukprasert . (Now with video)

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Wing Commander Maneepan Robchanachai. Photos by Chumporn Sangvilert

This is an excerpt from a much longer story in today's Life section of the Bangkok Post. You can read it in full here: http://www.bangkokpost.com/news/special-reports/625836/flying-with-the-rainmaker

Flying with the rainmaker

Pattramon Sukprasert 

Nearly every morning, Wing Commander Maneepan Robchanachai  pilots the Caravan, a single-engine turboprop, and performs rain-making operations with his team from the Department of Royal Rainmaking and Agricultural Aviation.

"Rainmaking is both art and science," he says. "The process on how each chemical reacts with the cloud is based on scientific theories, but it requires imagination and experience from pilots to know which coordinates and which direction to fly."

An aircraft from the Department of Royal Rainmaking and Agricultural Aviation during a recent flight in Nakhon Sawan.

Every morning Wg Cdr Maneepan, in his green overalls, attends a meeting with meteorological experts to discuss the weather conditions and decide whether it is suitable to fly and make rain. Factors affecting the ability to make artificial precipitation include humidity, sunlight, and wind speed. Before setting off, each pilot learns of the location and altitude of the flight, as well as reviews the previous day's result. The officers then earmark which and how much chemical content – sodium chloride, calcium chloride, dry ice and urea – will be brought with the aircraft for the upcoming flights of the day.

This morning, the weather clears and the pilots are getting ready, while the staff and volunteers — mostly farmers — help load materials into the aircraft. Wg Cdr Maneepan walks around his Caravan and does a final check-up to ensure that the aircraft is in perfect condition to fly.

On every flight, there is a scientist in the cockpit next to the pilot, an officer to distribute the chemicals and a technician in case of emergency. The cabin floor is modified, with a hole that connects to a tube outside the aircraft for dispersing the 700kg of chemical materials.

"This year the drought is severe. I can tell by just looking," says the 58-year-old pilot. "If we look down while flying, we can see it's more brown than green. The rivers have really run dry."

"Unlike regular pilots who must fly avoiding clouds, we need to run into them, or our mission is incomplete," Wg Cdr Maneepan explains while heading to cloudy areas. "Royal Rainmaking Pilots also need to know how to fly together with other aircraft as some steps require more than one plane at a time."

At one point, the scientist signals the officer at the back to disperse the chemicals while the pilot keeps flying into cloudy areas.

Staff load chemicals into the cabin.

There are usually three flights per day and each performs different steps in the rain-making process. The first is "agitating", using sodium chloride to stimulate humidity and vapour. The second is "fattening", which uses calcium chloride to stimulate cloud density. The last step is "attacking", with dry ice and ground urea to make moisture condense into liquid. The first step can be skipped if the cloud condition is ready for the second step.

"The rain we make is natural, but what we do is modify the weather by speeding up the process or increase the amount and extent of rainfall," says Wg Cdr Maneepan.

Here is a video of the process by Chumporn Sangvilert.

สามารถฝึกอ่านออกเสียงและดูคำแปลได้ที่ : http://www.bangkokpost.com/learning/learning-from-news/626036/the-rainmaker