Colonel Peter Pan to make rain fall

The air force yesterday dispatched two C-130H aircraft to execute the first cloud-seeding operations of the year, hoping to raise water levels in major reservoirs in northern Taiwan.

Colonel Peter Pan (潘大綱), director of the air force's weather center, said before yesterday's takeoff that it is hard to predict how effective the mission would be.

"If we need quotable statistics, we have to run more flights. Each flight varies in its result because of the differences in weather conditions," Pan said.

"Some flights might help generate more rainfall than expected, while others might not produce satisfactory results," he said.

Despite the lack of a long-term analysis over the effectiveness of cloud-seeding, Pan said, the air force may still study the result of each flight.

"One way is to find out if the rainfall in the targeted areas [for cloud-seeding] increases after dropping rain catalysts. Another is to notice any change in the weather images collected by radar satellites," he said.

"There are still other ways for us to choose. Generally speaking, rain-boosting missions can help increase rainfall by 10 percent to 20 percent," he said.

The planes dropped 300kg of dry ice and about 8,000 liters of water yesterday over the Shihmen reservoir in Taoyuan and the Feitsui reservoir in suburban Taipei.

Similar cloud-seeding operations were conducted last year.

Last year's operations were the first since 1994 and were launched to help relieve one of the most serious droughts in recent years.

The two planes took off from Taipei's Sungshan airport at 3pm yesterday

The flights were timed to coincide with the arrival of clouds from China's coastal provinces.

The air force said it expects cloud-seeding to increase daily rainfall in the vicinity of the two reservoirs by 10 percent to 15 percent.

The air force started "rain-making" missions in 1951, having dispatched 199 aircraft sorties for the purpose to date, according to information provided by air force general headquarters.

It now uses the term of "rain enhancement" to replace "rain making" since it is a more accurate description.

Taiwan is one of the many countries still continuing the practice. Other countries include the US, Israel, South Africa, Italy, Thailand, Australia and China.

The air force did not use the C-130H for cloud-seeding until 1991. The plane is known for its heavy lift capabilities.

As of 5pm, the Feitsui reservoir recorded 6.78mm of rainfall, while the Shihmen reservoir registered only 1.7mm of rainfall.