Forest fires are burning both above ground and underground in Indonesia following a severe and widespread dry spell, according to the National Aeronautics and Space Administration (NASA).
In a Facebook post today, NASA said some of the fires were burning in tropical peatlands, where fires can smoulder slowly and produce higher levels of air pollution.
Such fires are also particularly difficult to extinguish because they burn at low temperatures and can spread beneath the ground.
NASA said imagery captured by its Aqua satellite showed smoke blanketing large parts of Indonesia and Malaysia on Sept 1.
The agency added red markers to the image to indicate thermal anomalies detected by its Moderate Resolution Imaging Spectroradiometer (MODIS), which can signal the presence of fires.
However, NASA said increasingly thick smoke and cloud cover were making it difficult for the instrument to detect fires beneath the forest canopy and underground.
Indonesia is home to about 36 per cent of the world’s tropical peatlands. NASA said the country released an estimated 1.75 billion tonnes of greenhouse gases in 2015 after fires burned for more than three months.
As of Sept 2 this year, fires that had been burning for about a month had already released an estimated 10 per cent of the greenhouse gas emissions produced by the 2015 fires, NASA said.
The fires and resulting haze have also disrupted daily activities, with schools beginning to shift to remote learning while several flights have reportedly experienced delays.
An ecologist from the University of Maryland Centre for Environmental Science said continued attention was needed to tackle the fires, stressing that efforts should not only intensify during El Niño events, when fires typically become more severe.
He said a more sustained approach was needed to address forest and peatland fires, particularly as increasingly dry weather raises the risk of further outbreaks.
