Severe Air Pollution Due to Peat Fires During 2015 Super El Niño in Central Kalimantan, Indonesia

Author(s):  
Hiroshi Hayasaka ◽  
Alpon Sepriando
2016 ◽  
Vol 16 (18) ◽  
pp. 11711-11732 ◽  
Author(s):  
Chelsea E. Stockwell ◽  
Thilina Jayarathne ◽  
Mark A. Cochrane ◽  
Kevin C. Ryan ◽  
Erianto I. Putra ◽  
...  

Abstract. Peat fires in Southeast Asia have become a major annual source of trace gases and particles to the regional–global atmosphere. The assessment of their influence on atmospheric chemistry, climate, air quality, and health has been uncertain partly due to a lack of field measurements of the smoke characteristics. During the strong 2015 El Niño event we deployed a mobile smoke sampling team in the Indonesian province of Central Kalimantan on the island of Borneo and made the first, or rare, field measurements of trace gases, aerosol optical properties, and aerosol mass emissions for authentic peat fires burning at various depths in different peat types. This paper reports the trace gas and aerosol measurements obtained by Fourier transform infrared spectroscopy, whole air sampling, photoacoustic extinctiometers (405 and 870 nm), and a small subset of the data from analyses of particulate filters. The trace gas measurements provide emission factors (EFs; grams of a compound per kilogram biomass burned) for up to  ∼  90 gases, including CO2, CO, CH4, non-methane hydrocarbons up to C10, 15 oxygenated organic compounds, NH3, HCN, NOx, OCS, HCl, etc. The modified combustion efficiency (MCE) of the smoke sources ranged from 0.693 to 0.835 with an average of 0.772 ± 0.053 (n  =  35), indicating essentially pure smoldering combustion, and the emissions were not initially strongly lofted. The major trace gas emissions by mass (EF as g kg−1) were carbon dioxide (1564 ± 77), carbon monoxide (291 ± 49), methane (9.51 ± 4.74), hydrogen cyanide (5.75 ± 1.60), acetic acid (3.89 ± 1.65), ammonia (2.86 ± 1.00), methanol (2.14 ± 1.22), ethane (1.52 ± 0.66), dihydrogen (1.22 ± 1.01), propylene (1.07 ± 0.53), propane (0.989 ± 0.644), ethylene (0.961 ± 0.528), benzene (0.954 ± 0.394), formaldehyde (0.867 ± 0.479), hydroxyacetone (0.860 ± 0.433), furan (0.772 ± 0.035), acetaldehyde (0.697 ± 0.460), and acetone (0.691 ± 0.356). These field data support significant revision of the EFs for CO2 (−8 %), CH4 (−55 %), NH3 (−86 %), CO (+39 %), and other gases compared with widely used recommendations for tropical peat fires based on a lab study of a single sample published in 2003. BTEX compounds (benzene, toluene, ethylbenzene, xylenes) are important air toxics and aerosol precursors and were emitted in total at 1.5 ± 0.6 g kg−1. Formaldehyde is probably the air toxic gas most likely to cause local exposures that exceed recommended levels. The field results from Kalimantan were in reasonable agreement with recent lab measurements of smoldering Kalimantan peat for “overlap species,” lending importance to the lab finding that burning peat produces large emissions of acetamide, acrolein, methylglyoxal, etc., which were not measurable in the field with the deployed equipment and implying value in continued similar efforts. The aerosol optical data measured include EFs for the scattering and absorption coefficients (EF Bscat and EF Babs, m2 kg−1 fuel burned) and the single scattering albedo (SSA) at 870 and 405 nm, as well as the absorption Ångström exponents (AAE). By coupling the absorption and co-located trace gas and filter data we estimated black carbon (BC) EFs (g kg−1) and the mass absorption coefficient (MAC, m2 g−1) for the bulk organic carbon (OC) due to brown carbon (BrC). Consistent with the minimal flaming, the emissions of BC were negligible (0.0055 ± 0.0016 g kg−1). Aerosol absorption at 405 nm was  ∼  52 times larger than at 870 nm and BrC contributed  ∼  96 % of the absorption at 405 nm. Average AAE was 4.97 ± 0.65 (range, 4.29–6.23). The average SSA at 405 nm (0.974 ± 0.016) was marginally lower than the average SSA at 870 nm (0.998 ± 0.001). These data facilitate modeling climate-relevant aerosol optical properties across much of the UV/visible spectrum and the high AAE and lower SSA at 405 nm demonstrate the dominance of absorption by the organic aerosol. Comparing the Babs at 405 nm to the simultaneously measured OC mass on filters suggests a low MAC ( ∼  0.1) for the bulk OC, as expected for the low BC/OC ratio in the aerosol. The importance of pyrolysis (at lower MCE), as opposed to glowing (at higher MCE), in producing BrC is seen in the increase of AAE with lower MCE (r2 =  0.65).


2016 ◽  
Author(s):  
Chelsea E. Stockwell ◽  
Thilina Jayarathne ◽  
Mark A. Cochrane ◽  
Kevin C. Ryan ◽  
Erianto I. Putra ◽  
...  

Abstract. Peat fires in Southeast Asia have become a major annual source of trace gases and particles to the regional-global atmosphere. The assessment of their influence on atmospheric chemistry, climate, air quality, and health has been uncertain partly due to a lack of field measurements of the smoke characteristics. During the strong 2015 El Niño event we deployed a mobile smoke sampling team in the Indonesian province of Central Kalimantan on the island of Borneo and made the first, or rare, field measurements of trace gases, aerosol optical properties, and aerosol mass emissions for authentic peat fires burning at various depths in different peat types. This paper reports the trace gas and aerosol measurements obtained by Fourier transform infrared spectroscopy, whole air sampling, photoacoustic extinctiometers (405 and 870 nm), and a small subset of the data from analyses of particulate filters. The trace gas measurements provide emission factors (EFs, g compound per kg biomass burned) for CO2, CO, CH4, non-methane hydrocarbons up to C10, 15 oxygenated organic compounds, NH3, HCN, NOx, OCS, HCl, etc.; up to ~90 gases in all. The modified combustion efficiency (MCE) of the smoke sources ranged from 0.693 to 0.835 with an average of 0.772 ± 0.053 (n = 35) indicating essentially pure smoldering combustion and the emissions were not initially strongly lofted. The major trace gas emissions by mass (EF as g/kg) were: carbon dioxide (1564 ± 77), carbon monoxide (291 ± 49), methane (9.51 ± 4.74), hydrogen cyanide (5.75 ± 1.60), acetic acid (3.89 ± 1.65), ammonia (2.86 ± 1.00), methanol (2.14 ± 1.22), ethane (1.52 ± 0.66), dihydrogen (1.22 ± 1.01), propylene (1.07 ± 0.53), propane (0.989 ± 0.644), ethylene (0.961 ± 0.528), benzene (0.954 ± 0.394), formaldehyde (0.867 ± 0.479), hydroxyacetone (0.860 ± 0.433), furan (0.772 ± 0.035), acetaldehyde (0.697 ± 0.460), and acetone (0.691 ± 0.356). These field data support significant revision of the EFs for CO2 (−8 %), CH4 (−55 %), NH3 (−86 %), CO (+39 %) and other gases compared with widely-used recommendations for tropical peat fires based on a lab study of a single sample published in 2003. BTEX compounds (benzene, toluene, ethylbenzene, xylenes) are important air toxics and aerosol precursors and were emitted in total at 1.5 ± 0.6 g/kg. Formaldehyde is probably the air toxic gas most likely to cause local exposures that exceed recommended levels. The field results from Kalimantan were in reasonable agreement with recent (2012) lab measurements of smoldering Kalimantan peat for “overlap species,” lending importance to the lab finding that burning peat produces large emissions of acetamide, acrolein, methylglyoxal, etc., which were not measureable in the field with the deployed equipment and implying value in continued similar efforts. The aerosol optical data measured include EFs for the scattering and absorption coefficients (EF Bscat and EF Babs, m2/kg fuel burned) and the single scattering albedo (SSA) at 870 and 405 nm, as well as the absorption Ångstrӧm exponents (AAE). By coupling the absorption and co-located trace gas and filter data we estimated black carbon (BC) EFs (g/kg) and the mass absorption coefficient (MAC, m2/g) for the bulk organic carbon (OC) due to brown carbon (BrC). Consistent with the minimal flaming, the emissions of BC were negligible (0.0055 ± 0.0016 g/kg). Aerosol absorption at 405 nm was ~52 times larger than at 870 nm and BrC contributed ~96 % of the absorption at 405 nm. Average AAE was 4.97 ± 0.65 (range, 4.29–6.23). The average SSA at 405 nm (0.974 ± 0.016) was marginally lower than the average SSA at 870 nm (0.998 ± 0.001). These data facilitate modeling climate-relevant aerosol optical properties across much of the UV/visible spectrum and the high AAE and lower SSA at 405 nm demonstrate the dominance of absorption by the organic aerosol. Comparing the Babs at 405 nm to the simultaneously measured OC mass on filters suggests a low MAC (~0.1) for the bulk OC, as expected for the low BC / OC ratio in the aerosol. The importance of pyrolysis (at lower MCE), as opposed to glowing (at higher MCE), in producing BrC is seen in the increase of AAE with lower MCE (r2 = 0.65).


2020 ◽  
Vol 8 (2) ◽  
pp. 100
Author(s):  
Nina Yulianti ◽  
Kitso Kusin ◽  
Daisuke Naito ◽  
Masahiro Kawasaki ◽  
Osamu Kozan ◽  
...  

<p class="Abstract">fires in Indonesia. About thirty percent of the total fires are spread in Central Kalimantan Province. Symptoms of climate change in the form of increasingly frequent weather and extreme climate phenomena support the severity of forest and land fires which results in increased release of air pollution gases. In 2015, the peak fire months had emitted a high concentration of air pollutant gasses and causes hazardous air pollution. This study aims to investigate the latest severe fire occurrence and haze conditions in Central Kalimantan. Hotspot data was from 2006 to 2017, visibility data were from four times of El Niño event, Particle Matter Size 10 (PM 10) data and Pollution Standard Index (PSI) was from very strong El Niño in 2015 comparison to La Niña in 2016/2017. The results showed that the top incidents occurred not only very strong in 2015 but also weak El Niño in 2006. The most of dense hotspots density in the last twelve years (&gt; 50% of fires in the area) found in peatlands in Pulang Pisau, Palangka Raya and Kapuas.  Palangka Raya's case, dangerous of APSI with PM10 concentrations of more than 500 µg m-3 occurred for 2 (two) months, from the end of August to the early of November 2015. The maximum peak concentration of PM10 is as high as 3000 μg m-3, which is higher than other fire years. Based on the data obtained, the haze was blanketed Palangka Raya was getting thicker at the end of October. As a result, visibility is decreasingly limited, only around 200 to 900 m during the peak season and air pollution-related-peat fire. Thus, this severe condition could rose multiple effects, which will exacerbate climate change, environmental sustainability and the livelihoods of thousands of peoples.</p>


2019 ◽  
Vol 19 (1) ◽  
pp. 565-576 ◽  
Author(s):  
Ge Zhang ◽  
Yang Gao ◽  
Wenju Cai ◽  
L. Ruby Leung ◽  
Shuxiao Wang ◽  
...  

Abstract. Utilizing a recent observational dataset of particulate matter with diameters less than 2.5 µm (PM2.5) in North China, this study reveals a distinct seesaw feature of abnormally high and low PM2.5 concentrations in the adjacent two months of December 2015 and January 2016, accompanied by distinct meteorological modulations. The seesaw pattern is postulated to be linked to a super El Niño and the Arctic Oscillation (AO). During the mature phase of El Niño in December 2015, the weakened East Asian winter monsoon (EAWM) and the associated low-level southerly wind anomaly reduced planetary boundary layer (PBL) height, favoring strong haze formation. This circulation pattern was completely reversed in the following month, in part due to a sudden phase change of the AO from positive to negative and the beginning of a decay of the El Niño, which enhanced the southward shift of the upper tropospheric jet from December to January relative to climatology, leading to an enhanced EAWM and substantially lower haze formation. This sub-seasonal change in circulation is also robustly found in 1982–1983 and 1997–1998, implicative of a general physical mechanism dynamically linked to El Niño and the AO. Numerical experiments using the Weather Research and Forecasting (WRF) Community Multiscale Air Quality (CMAQ) model were used to test the modulation of the meteorological conditions on haze formation. With the same emission, simulations for three super El Niño periods (1983, 1997 and 2015) robustly show higher PM2.5  concentrations under the mature phase of the super El Niño, but substantially lower PM2.5 concentrations during the decay phase of El Niño (and the sudden AO phase change), further verifying the modulation effect of the sub-seasonal circulation anomaly on PM2.5 concentrations in North China.


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