Indonesia Battles Forest Fires as Dry Conditions Raise Regional Haze Concerns

Indonesia is facing a renewed threat from forest and land fires as dry-season conditions increase the risk of burning across parts of the sprawling archipelago, particularly in fire-prone areas of Sumatra and Kalimantan.

Satellite monitoring continues to play an important role in detecting active fires across Indonesia. NASA’s Fire Information for Resource Management System, known as FIRMS, provides near-real-time observations from MODIS and VIIRS satellite instruments, allowing authorities and researchers to identify heat signatures associated with possible fires.

The renewed fire activity comes during Indonesia’s annual dry season, when forests, agricultural areas and especially dried peatlands can become highly vulnerable to burning.

Peat Fires Create a Particular Challenge

Indonesia contains extensive tropical peatlands — ecosystems made up of partially decomposed organic material accumulated over thousands of years.

When peatlands remain wet, they are naturally resistant to fire. But drainage and prolonged dry conditions can lower water levels, allowing peat to dry and become highly combustible.

Unlike ordinary surface fires, peat fires can burn underground and smolder for extended periods. They can also produce large quantities of dense smoke, making them particularly difficult to detect and extinguish.

NASA studies of earlier Indonesian fire seasons have shown that drained peatlands are especially vulnerable during periods of drought.

Haze Can Travel Beyond Indonesia Smoke from Indonesian fires does not necessarily remain near the source. Depending on wind direction and atmospheric conditions, smoke from fires in Sumatra and Kalimantan can move across surrounding seas and affect neighboring parts of Southeast Asia.

Malaysia, Singapore and other nearby areas have experienced transboundary haze during severe Indonesian fire seasons in the past.

The smoke can contain high concentrations of fine particles capable of remaining suspended in the atmosphere and traveling considerable distances.

For that reason, developments in Indonesia are closely watched throughout Southeast Asia whenever fire activity increases during the dry season.

El Niño Can Increase the Risk

Indonesia’s fire risk can become particularly serious during El Niño conditions. El Niño changes atmospheric circulation across the tropical Pacific and can reduce rainfall over Indonesia, creating longer and more severe dry periods. NASA research examining earlier Indonesian fire seasons has found a strong relationship between El Niño-related drought and major increases in fire activity. The combination of lower rainfall, dry vegetation and dehydrated peat can allow relatively small fires to spread rapidly and become much more difficult to control.

Satellite Technology Helps Track Fires

Indonesia’s geography makes fire monitoring particularly challenging.

The country stretches across thousands of islands, and some fires occur in remote forests and peatlands that are difficult to reach from the ground.

Satellite observations therefore provide an important additional layer of information.

NASA FIRMS collects thermal data from several satellite instruments and identifies locations where unusually high surface temperatures may indicate active fires.

These observations can help authorities identify emerging hotspots, monitor the development of existing fires and assess areas where additional firefighting resources may be required.

Satellite observations do have limitations. Clouds and heavy smoke can sometimes obscure the surface, and a detected hotspot does not automatically mean that a large uncontrolled wildfire is present.

Recurring Environmental Challenge

Forest and peatland fires have been a recurring environmental issue in Indonesia for decades.

Some fires are associated with agricultural activity and land clearing, while others can spread from existing burns during particularly hot and dry conditions.

NASA has documented major Indonesian fire episodes in which smoke spread across Sumatra and Borneo and affected air quality far beyond the immediate fire areas.

Peatlands make the challenge particularly difficult because fires can continue burning beneath the surface even after visible flames have disappeared.

Regional Attention Likely to Remain High

With Indonesia moving through its dry season, fire and haze conditions are likely to remain closely monitored in the coming weeks.

The severity of the situation will depend heavily on rainfall, wind conditions, the number of new fires and authorities’ ability to contain outbreaks before they spread into larger forest or peatland areas.

The broader concern extends beyond Indonesia itself.

Severe fires have the potential to affect public health, transportation, tourism and economic activity across Southeast Asia if large quantities of smoke are carried across national borders. For now, satellite surveillance provides one of the clearest ways to follow how Indonesia’s fire season develops — and whether current outbreaks remain localized or evolve into a wider regional haze problem.

NASA Earth Observatory / NASA Earth Science — information on Indonesian forest and peatland fires, satellite monitoring, dry-season fire behavior and the relationship between El Niño and severe Indonesian fire seasons. NASA Science