Hazy times for Singapore

Vegetation and peatland fires occur frequently across Southeast Asia. These fires result in extensive deforestation and forest degradation and release large quantities of carbon dioxide and other pollutants into the atmosphere. Particulate pollution emitted from these fires is of major concern because it has adverse effects on regional air quality, and consequently on human health. The location of these fires can be determined by satellite, but in order to take effective action to improve air quality in this region, it is crucial to identify the fire regions that contribute most to particulate pollution in areas of high human population downwind of the fires.

LEAF scientists from the Institute for Climate and Atmospheric Science (ICAS) in the School of Earth and Environment have been investigating the fires which contributed to poor air quality over Singapore between 2004 and 2009.

In their study, published recently in Environmental Research Letters, the LEAF scientists combined two different computer modelling approaches; one that simulates the whole atmosphere, and one that follows the path of parcels of air arriving in Singapore.

Dr Carly Reddington, lead author on the study explains, "To identify the fire regions that are responsible for the greatest air quality degradation in certain cities, it is not only important to know the fire location but also how much smoke the fires emit, where this smoke is transported to by the prevailing wind, and how the smoke plume ages - this is why we need to use models of the atmosphere".

The LEAF team found from both modelling approaches that fires in southern Sumatra contributed the most to particulate matter concentrations in Singapore, with secondary contributions from fires in central Sumatra and Kalimantan (Indonesian Borneo).

In addition, these fires were found to be affecting the air in other locations, “As well as contributing to pollution in Singapore, we found that fires in Sumatra and Kalimantan also degrade air quality in other major cities across Southeast Asia such as Kuala Lumpur and Jakarta”, added Dr Reddington. “We suggest that targeting fire reduction efforts in southern and central Sumatra will not only improve air quality in Singapore but also in other major cities in the region”.

Find out more about our research into forest fires here.