BANGKOK - Overnight rain cleared away choking smoke in parts of northern Thailand, but more will take its place soon as the deluge was a one off and farmers are planning to burn more stubble, officials said on Wednesday. The rain, which came four days later than meteorologists had forecast, also brought wind that blew away the smoke from stubble burning and forest fires and air was clear in the region's main cities, they said.
"We had a clear sky this morning," an environmental officer said in Chiang Rai after the region's first rain since November in what has been an unusually long and dry cool season.
Smoke from burning fields and forests in Thailand, Laos and Myanmar had poured into valleys in the hilly region as a cold front prevented it from escaping into the atmosphere.
Authorities in Singapore said the city-state experienced a slight haze earlier in the week brought on by the fires in the region, but the air quality had since improved and was well within permissible levels.
Singapore's Pollutant Standards Index (PSI) hit a reading of 52 on Monday following the haze but fell back to 40 on Wednesday as air quality improved.
A reading of 51 to 100 indicates "moderate" air quality whereas a reading of 0 to 50 indicates "good" air quality.
"The slight haze could be attributed to the accumulation of particulate matter from around the region due to weak and variable winds," the National Environment Agency said on its Web site.
"The sources of these particles could include the smoke haze particles carried over from the fires in northern ASEAN region," it said.
In Thailand's Chiang Mai, the regional tourism centre, the air quality went overnight from "dangerous to the health of children and the elderly" to acceptable levels, officials said.
But in nearby Mae Hong Son province, where flights have been disrupted sporadically for two weeks, there had been no rain and the smoke-filled air remained dangerous to health, a Thai Airways official said.
"Though we can fly two flights today, I won't say the weather conditions have improved significantly," airline station manager Taewan Dumronghud told Reuters by telephone from the town of Mae Hong Son near the Myanmar border.
"We have to decide hour by hour if we can fly the next one."
And the clear skies of Chiang Mai might be short lived as no more rain was expected until early April, when the main stubble burning and slash-and-burn farming begins.
"Satellite pictures show trees have been cut down, awaiting a new round of burning to make land for new crops in April," Apiwat Kunarak, head of the northern environmental office, told Reuters. (Additional reporting by Gui Qing in Singapore)
REUTERS NEWS SERVICE
