Haze may hit Singapore in 2 weeks - it all depends on the wind

Forecast of south-westerly winds means smoke from Sumatran fires could hit soon
Tania Tan, Business Times 22 May 08;

THE smoke from fires in Indonesia could hit Singapore sooner rather than later.

Unpredictable wind conditions at this time of year could mean that the haze, caused by Sumatran fires, may be here in two weeks.

All it will take is for the winds to blow in a south-westerly direction - exactly what the National Environment Agency (NEA) has forecast for the next fortnight.

In any case, one thing is for sure unless the fires are quelled: It is only a matter of time before Singapore is enveloped in haze.

Between June and September, south-westerly winds are expected to strengthen, said Associate Professor Matthias Roth of the National University of Singapore's geography department - and this could blow the acrid pall this way.

The thick smoke over Sumatra has resulted from an earlier-than-usual start to the slash-and-burn season in Indonesia.

Soaring temperatures and drier vegetation have helped prime the land for burning, and hundreds of hot spots have appeared over the past few days, the Indonesian meteorological service reported.

Over 850 hot spots were counted last week, up from just 130 the week before, said the NEA,which added that about 270 hot spots have been sighted in Sumatra since Monday.

And there may be more. Cloud cover has obscured some areas, resulting in partial satellite images.

The National University of Singapore's Centre for Remote Imaging, Sensing and Processing (Crisp) said the fires were raging earlier than usual.

'They popped up suddenly,' said Crisp director Kwoh Leong Keong. 'Most started over the weekend.'

In May, the usual number of hot spots is between 30 and 40, he said.

The number of fires typically starts to climb in June, peaking in July, he added.

'Hundreds is definitely on the high side for this time of year,' noted Mr Kwoh. 'You usually see those numbers in July.'

There are so many fires that the smoke from them has led to poor visibility in parts of Kalimantan.

On Tuesday, the thick smoke forced temporary airport closures.

Prof Roth said a weakening La Nina effect is not helping things.

La Nina is a weather phenomenon which results in lower temperatures in the Pacific Ocean, leading to wet weather.

A weakening effect means higher temperatures, leading to more fires.

The combination of more fires being set and hotter weather points to a repeat of what happened in 2006, when Singapore experienced its worst haze in a decade, with the air quality in the unhealthy range.

Crisp's Mr Kwoh said the next two months will bear watching. If hot-spot numbers keep rising, it will be a sign that hazy days are ahead.

The problem has plagued the region since 1997.

Many farmers and plantation owners in Sumatra and Borneo use the slash-and-burn technique to clear large tracts of land, usually in the middle of the year, ahead of the planting season.

The problem prompted countries affected by the haze, including Singapore, to set up a task force to combat the problem.

Members of the task force are collaborating with Indonesia to develop action plans to mitigate the haze problem. These include encouraging alternative land-clearing methods and implementing fire-monitoring systems.