After several years of comparatively quiet fire seasons, Indonesia saw the return of intense, smoky fires in 2023. The blazes have been exacerbated by dry conditions made worse this year by the return of El Niño.
This image shows smoke from fires burning on the island of Borneo, in the Indonesian provinces of South and Central Kalimantan. It was acquired by the MODIS (Moderate Resolution Imaging Spectroradiometer) sensor on NASA’s Terra satellite on October 2, 2023. By that date, fire had burned around 267,900 hectares (662,000 acres) since the start of the year, surpassing the area burned during all of 2022, according to news reports.
The image below (left) shows burn scars on the landscape near Banjarbaru, the capital city of South Kalimantan, on September 27, 2023. Most of the reds and dark browns are scars from fires that have burned so far during the 2023 fire season. Lighter browns are likely dry vegetation. For comparison, the other image (right) shows the same area on August 7, 2022. Both images are false color and were acquired by the OLI-2 (Operational Land Imager-2) on Landsat 9.
Burning in Indonesia often begins as farmers clear land for crops or grazing animals. Fire that escapes control in Borneo and Sumatra can become difficult to extinguish because of the islands’ large deposits of peat—a soil-like mixture of partly decayed plant material that can fuel smoldering fires for months.
Fires generally correspond with Indonesia’s dry season, which runs from June into December, with fire activity peaking from August into October. This year, scientists think that the natural climate phenomenon El Niño has made the landscape even drier, priming it to burn. During El Niño years, rain that is normally centered over Indonesia and the far western Pacific shifts eastward into the central Pacific, causing parts of Indonesia to experience drought.
“This El Niño has maybe been delayed in drying out the main burning regions,” said NASA and Columbia University scientist Robert Field. “But it is the simplest explanation for the drying, along with a positive Indian Ocean Dipole to the west.”
Josh Willis, an oceanographer and Sentinel-6 Michael Freilich project scientist at NASA’s Jet Propulsion Laboratory, agrees that El Niño is likely playing a role in the dryness this year. Similar scenarios unfolded during El Niño events that ramped up beginning in 1997 and 2015, alongside significant drought in Indonesia. Willis noted that by September of those years, El Niño was already several times stronger than the current one. But that might not matter much when it comes to fire.
“Just because it’s not a huge El Niño doesn’t mean it’s not causing impacts, especially in the tropics,” Willis said. “Indonesia is close to the ocean regions that are the warmest in the world during a neutral or La Niña year. During an El Niño year, even a moderate one, those areas typically dry out.”
The drought is apparent in a map from Indonesia’s meteorological agency provided as part of the Forest and Land Fire Warning System (SPARTAN). SPARTAN uses data from IMERG (Integrated Multi-Satellite Retrievals for GPM)—a product of the GPM (Global Precipitation Measurement) satellite mission—to track regions at high risk of burning, especially from peat fires.
NASA Earth Observatory images by Lauren Dauphin, using MODIS data from NASA EOSDIS LANCE and GIBS/Worldview and Landsat data from the U.S. Geological Survey. Story by Kathryn Hansen.
Baada ya miaka kadhaa ya msimu wa moto wa utulivu, Indonesia iliona kurudi kwa moto mkali na wa moshi mnamo 2023. Moto huo umezidi kuongezeka kwa sababu ya ukame ambao umekuwa ukizidi kuongezeka mwaka huu kwa sababu ya kurudi kwa El Niño. Picha hii inaonyesha moshi kutoka kwa moto unaowaka kwenye kisiwa cha Borneo, katika mikoa ya Indonesia ya Kalimantan Kusini na Kati. Picha hiyo ilitolewa na kipimaji cha MODIS (Moderate Resolution Imaging Spectroscopy) kilichokuwa kwenye satelaiti ya NASA ya Terra mnamo Oktoba 2, 2023. Maelfu ya watu waliuawa katika moto huo ambao uliwaka eneo la hekta 267,900 tangu mwanzo wa mwaka, na kuizidi eneo lililowaka moto mwaka 2022, kulingana na ripoti za habari. Picha ya chini (kushoto) inaonyesha makovu ya kuchomwa kwenye mandhari karibu na Banjarbaru, mji mkuu wa Kalimantan Kusini, Septemba 27, 2023. "Mchanga na rangi nyekundu ni alama za moto ambao umewaka hadi sasa katika msimu wa moto wa 2023.""" Huenda mimea yenye rangi ya kahawia nyepesi ikawa kavu. Kwa kulinganisha, picha nyingine (kushoto) inaonyesha eneo moja mnamo Agosti 7, 2022. Picha hizo mbili zilikuwa na rangi bandia na zilitolewa na OLI-2 (Operational Land Imager-2) kwenye Landsat 9. Kuungua kwa ardhi nchini Indonesia mara nyingi huanza wakati wakulima wanapofungua ardhi kwa ajili ya mazao au wanyama wa malisho. Moto unaopatikana katika visiwa vya Borneo na Sumatra ni mkubwa sana na unaweza kuwaka kwa sababu ya mchanganyiko wa mchanga unaofanana na udongo wa mimea iliyoharibika ambayo inaweza kuchochea moto kwa miezi mingi. Moto kwa ujumla unalingana na msimu wa ukame wa Indonesia, ambao huanzia Juni hadi Desemba, na shughuli za moto zinafikia kilele kutoka Agosti hadi Oktoba. Wanasayansi wanasema hali ya hewa ya El Niño imesababisha ukame wa nchi hiyo. Katika miaka ya El Niño, mvua ambayo kwa kawaida huanguka juu ya Indonesia na sehemu ya magharibi ya Pasifiki, hubadilika kuelekea mashariki kuelekea katikati ya Pasifiki, na kusababisha sehemu za Indonesia kukumbwa na ukame. "El Niño hii labda imecheleweshwa katika kukausha maeneo makuu ya kuchoma", alisema mwanasayansi wa NASA na Chuo Kikuu cha Columbia Robert Field. "Josh Willis, mwanasayansi wa mradi wa Sentinel-6 Michael Freilich katika Maabara ya NASA ya Jet Propulsion, anakubali kwamba El Niño inawezekana kuwa na jukumu katika ukame wa mwaka huu.""" Hali kama hiyo ilitokea wakati wa El Niño, ambayo iliongezeka kuanzia mwaka 1997 na 2015, pamoja na ukame mkubwa nchini Indonesia. Willis alibainisha kwamba kufikia Septemba ya miaka hiyo, El Niño ilikuwa tayari yenye nguvu mara kadhaa kuliko ile ya sasa. Lakini hilo huenda lisiwe na maana sana linapohusu moto. "Kwa sababu tu si El Niño kubwa haimaanishi haisababishi athari, haswa katika maeneo ya kitropiki", Willis alisema. <unk>Indonesia iko karibu na mikoa ya bahari ambayo ni ya joto zaidi ulimwenguni wakati wa mwaka wa neutral au La Niña. Katika kipindi cha El Niño, hata maeneo hayo hufifia kwa kawaida, kulingana na ramani ya shirika la Indonesia la hali ya hewa iliyotolewa na mfumo wa kuonya moto wa misitu na ardhi (SPARTAN). SPARTAN hutumia data kutoka IMERG (Integrated Multi-Satellite Retrieval for GPM) - bidhaa ya ujumbe wa satelaiti ya GPM (Global Precipitation Measurement) - kufuatilia mikoa yenye hatari kubwa ya kuchoma, haswa kutoka kwa moto wa peat. Picha za NASA Earth Observatory na Lauren Dauphin, kutumia data ya MODIS kutoka NASA EOSDIS LANCE na GIBS, Worldview na Landsat data kutoka US Geological Survey. Hadithi ya Kathryn Hansen.