Hong Kong air pollution

Balloon-borne pollution probe set to soar up, up and away

Balloon to ascend to highest-ever altitude above city to test for pollutants and greenhouse gases

PUBLISHED : Monday, 15 July, 2013, 12:00am
UPDATED : Monday, 27 April, 2015, 3:29pm

Local hobby scientists are looking to measure atmospheric pollution up to 30 kilometres above Hong Kong by sending up probes attached to a helium balloon.

It's a project designed to show people that science doesn't take place only in laboratories.

"It's so crowded in the city that most people don't think we have the space for science," said Ricky Fan Hai-tai, president of the Hong Kong Environmental Protection Association, which is conducting the experiment.

Fan is not a scientist by training, but a management professional. For the past 31/2 years, he has been learning how to get his project off the ground, meeting equipment suppliers, scientists and the Civil Aviation Department.

"The Civil Aviation Department sent us a long list of questions about what we wanted to do," Fan said.

Ching Man-Leung, an expert on carbon emissions reduction and energy management, and a friend of Fan, joked: "Getting things done through other people - this is his expertise."

Scientists have been monitoring the atmosphere since the mid-1900s after becoming concerned about the effects of chemicals released by factories. The acidification of lakes, global warming and the depletion of the ozone layer top a list of concerns for Global Atmosphere Watch (GAW), a monitoring system set up by the UN's World Meteorological Organisation.

The Hong Kong Observatory is a party to the GAW, and monitors the atmosphere lower down.

But Fan said that his project will be the first time measurements have been taken so high above Hong Kong.

On June 30, Fan and his team of volunteers finally got a permit and sent up a test balloon to see how much weight it could carry.

Filled with small packets of seeds, tea and a camera, the balloon ascended, recording the views as it floated above the old Kai Tak airport, Cheung Chau, and finally high enough to see the thinning of the atmosphere and the darkness of space.

The helium expanded as the air pressure fell and the atmosphere thinned. Eventually the balloon burst and the box it was carrying deployed a parachute, which carried it on the wind across the border to Zhuhai as it sounded beeps to warn people below of its descent.

On September 19, a balloon will carry probes to measure atmospheric pollutants, ozone, nitrogen dioxide and other gases.

It will float above aircraft, which typically fly at an altitude of 10 kilometres, untethered and going wherever prevailing winds take it. The information gathered by the probes will be shared with local universities, said Fan.

"It all depends on the data gathered," he said. "If the level of ozone and pollutants is OK, then that's great. If not, then we've got some work to do."