The Indonesian authorities have tamed a growing number of forest fires in neighbouring Sumatra in the past few weeks with cloud-seeding, although the operations to produce rain have not been as successful as hoped, a top official has told The Straits Times.
As the dry season takes hold, the authorities in Indonesia and its neighbours are worried about a spike in forest fires and burning off on agricultural lands. Adding to concerns, a strengthening El Nino weather pattern, which usually causes higher temperatures and drought in the region, could prime parts of Sumatra and Borneo for major blazes in coming weeks. This could overwhelm fire-fighting efforts and trigger a choking smoke haze.
The authorities began cloud-seeding on June 22 in Riau province opposite Singapore, but a lack of clouds and moisture in the air meant on some days there were no clouds to seed, said Dr Heru Widodo, head of the weather-modification team at the Indonesian agency for the assessment and application of technology.
"But it is not that the cloud-seeding wasn't effective, only the success rate was lower than that in March. Had we not done anything, there would have been so much haze now," he told The Straits Times. A dry spell in March caused a brief surge in fires.
He rated the current cloud-seeding operations at seven points on a scale of one to 10, adding that the team had flown 11 flights so far and used more than 20 tonnes of cloud- seeding chemicals.
Number of fire hot spots in Sumatra late last month, according to Meteorological Service Singapore
Number of hot spots yesterday
The number of fire hot spots in Sumatra jumped late last month to about 150, then quickly fell before jumping back to nearly 140 late last week, according to Meteorological Service Singapore, citing satellite data. By yesterday, the number of hot spots fell to 18 from 56 on Sunday, going by the latest map posted.
Despite recent storms, fires have kept cropping up, Dr Heru said.
Fires have also been flaring up in Jambi province and further south.
"We have received reports of rising hot-spot activity in the southern part of Sumatra. We will set up a cloud-seeding operations base in Palembang, South Sumatra, on Wednesday," he said.
Since coming to office, Indonesian President Joko Widodo has pledged to be more active in fighting fires. Jakarta last September ratified the 2002 Asean Agreement on Transboundary Haze Pollution.
Under the agreement, countries have to cooperate in taking measures to prevent, monitor and mitigate the haze by controlling the sources of fires, in exchanging information and technology, and in helping one another manage outbreaks.
When asked last night about forest fires in Sumatra and the ongoing challenges faced by cloud-seeding operations, President Joko said "we will have the report tomorrow", in response to a question from The Straits Times during a breaking-of-fast event with reporters.