Thailand uses night temperature inversion data to predict PM2.5

The rainmaking department aims to forecast air quality more accurately and implement measures to improve conditions

The Royal Rainmaking and Agricultural Aviation Department has started measuring temperature inversions at night to better predict PM2.5 conditions for the following morning, the department’s deputy chief said. 

Rachen Silaparaya, deputy director-general of the department, explained that the practice now involves measuring temperature inversion between midnight and 2am, rather than just in the morning as was done previously. 

Temperature inversion occurs when warmer air sits above cooler air, the opposite of typical atmospheric pattern. This phenomenon can trap pollutants close to the ground, leading to poor air quality and smog. 

Rachen said that temperature measurements are being carried out at two locations: the Sattahip radar station and in Ratchaburi’s Photharam district.

The department is using measuring devices attached to balloons at both sites to collect data, which will help officials better predict PM2.5 levels in Bangkok and surrounding areas. 

Each device, tethered to a balloon, sends data back to ground stations as the balloon rises to an altitude of up to 30 kilometres. 

Once the balloon deflates, the device floats back to Earth with a small parachute, ensuring it does not pose any risk to people on the ground. 

He said data from the two devices will allow the department to plan rainmaking or cloud-seeding operations to improve air quality and weather conditions.

(2025/01/30-00:00)