scholarly journals Biomass Burning Aerosols and the Low Visibility Events in Southeast Asia

2016 ◽  
Author(s):  
Hsiang-He Lee ◽  
Rotem Z. Bar-Or ◽  
Chien Wang
Keyword(s):  
Particulate Matter ◽  
Southeast Asia ◽  
Biomass Burning ◽  
Wrf Model ◽  
Weather Conditions ◽  
General Situation ◽  
Kuala Lumpur ◽  
The Past ◽  
Low Visibility ◽  
Aerosol Module

Abstract. Fires including peatland burning in Southeast Asia have become a major concern of general public as well as governments in the region. This is because that aerosols emitted from such fires can cause persistent haze events under favorite weather conditions in downwind locations, degrading visibility and causing human health issues. In order to improve our understanding of the spatial-temporal coverage and influence of biomass burning aerosols in Southeast Asia, we have used surface visibility and particulate matter concentration observations, added by decadal long (2002 to 2014) simulations using the Weather Research and Forecasting (WRF) model with a fire aerosol module, driven by high-resolution biomass burning emission inventories. We find that in the past decade, fire aerosols are responsible for nearly all the events with very low visibility (< 7 km), and a substantial fraction of the low visibility events (visibility < 10 km) in the major metropolitan areas of Southeast Asia: 38 % in Bangkok, 35 % in Kuala Lumpur, and 34 % in Singapore. Biomass burnings in Mainland Southeast Asia account for the largest contributor to total fire produced PM2.5 in Bangkok (99.1 %), while biomass burning in Sumatra is the major contributor to fire produced PM2.5 in Kuala Lumpur (49 %) and Singapore (41 %). To examine the general situation across the region, we have further defined and derived a new integrated metric for 50 cities of the Association of Southeast Asian Nations, i.e., Haze Exposure Days (HEDs) that measures the annual exposure days of these cities to low visibility (< 10 km) caused by particulate matter pollution. It is shown that HEDs have increased steadily in the past decade across cities with both high and low populations. Fire events are found to be responsible for about half of the total HEDs. Therefore, our result suggests that in order to improve the overall air quality in Southeast Asia, mitigation policies targeting at both biomass and fossil fuel burning sources need to be put in effect.

scholarly journals Biomass burning aerosols and the low-visibility events in Southeast Asia

2017 ◽  
Vol 17 (2) ◽  
pp. 965-980 ◽  
Author(s):  
Hsiang-He Lee ◽  
Rotem Z. Bar-Or ◽  
Chien Wang
Keyword(s):  
Particulate Matter ◽  
Southeast Asia ◽  
Biomass Burning ◽  
Wrf Model ◽  
Weather Conditions ◽  
General Situation ◽  
Kuala Lumpur ◽  
The Past ◽  
Low Visibility ◽  
Aerosol Module

Abstract. Fires including peatland burning in Southeast Asia have become a major concern to the general public as well as governments in the region. This is because aerosols emitted from such fires can cause persistent haze events under certain weather conditions in downwind locations, degrading visibility and causing human health issues. In order to improve our understanding of the spatiotemporal coverage and influence of biomass burning aerosols in Southeast Asia, we have used surface visibility and particulate matter concentration observations, supplemented by decade-long (2003 to 2014) simulations using the Weather Research and Forecasting (WRF) model with a fire aerosol module, driven by high-resolution biomass burning emission inventories. We find that in the past decade, fire aerosols are responsible for nearly all events with very low visibility (< 7 km). Fire aerosols alone are also responsible for a substantial fraction of low-visibility events (visibility  < 10 km) in the major metropolitan areas of Southeast Asia: up to 39 % in Bangkok, 36 % in Kuala Lumpur, and 34 % in Singapore. Biomass burning in mainland Southeast Asia accounts for the largest contribution to total fire-produced PM2.5 in Bangkok (99 %), while biomass burning in Sumatra is a major contributor to fire-produced PM2.5 in Kuala Lumpur (50 %) and Singapore (41 %). To examine the general situation across the region, we have further defined and derived a new integrated metric for 50 cities of the Association of Southeast Asian Nations (ASEAN): the haze exposure day (HED), which measures the annual exposure days of these cities to low visibility (< 10 km) caused by particulate matter pollution. It is shown that HEDs have increased steadily in the past decade across cities with both high and low populations. Fire events alone are found to be responsible for up to about half of the total HEDs. Our results suggest that in order to improve the overall air quality in Southeast Asia, mitigation policies targeting both biomass burning and fossil fuel burning sources need to be implemented.

scholarly journals Haze in Singapore – Source Attribution of Biomass Burning from Southeast Asia

2018 ◽  
Author(s):  
Ayoe Buus Hansen ◽  
Wei Ming Chong ◽  
Emma Kendall ◽  
Boon Ning Chew ◽  
Christopher Gan ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Southeast Asia ◽  
Biomass Burning ◽  
Dispersion Model ◽  
Source Region ◽  
Weather Conditions ◽  
Peninsular Malaysia ◽  
Source Attribution ◽  
Maritime Continent ◽  
Source Regions

Abstract. This paper presents a study of haze in Singapore caused by biomass burning in Southeast Asia over the six year period from 2010 to 2015, using the Lagrangian dispersion model, NAME. The major contributing source regions are shown to be Riau, Peninsular Malaysia, South Sumatra, and Central and West Kalimantan. However, we see differences in haze concentrations and variation in the relative contributions from the various source regions between monitoring stations across Singapore, as well as on an inter-annual timescale. These results challenge the current popular assumption that haze in Singapore is dominated by emissions/burning from only Indonesia. It is shown that Peninsular Malaysia is a large source for the Maritime Continent off-season biomass burning impact on Singapore. As should be expected, the relatively stronger southeast monsoonal winds that coincide with increased biomass burning activities in the Maritime Continent create the main haze season from August to October (ASO), which brings particulate matter from several and varying source regions to Singapore. In contrast, atypical haze episodes in Singapore are characterised by atypical weather conditions, ideal for biomass burning, and emissions dominated by a single source region (for each event). The two most recent atypical haze events in mid 2013 and early 2014 have different source regions, whereas a different set of five regions dominate as major contributing source regions for most of the recent ASO haze seasons. Haze in Singapore varies across year, season, and location it is influenced by local and regional weather, climate, and regional burning. The study shows that even across small scales, such as in Singapore, variation in local meteorology can impact concentrations of particulate matter significantly, and emphasises the importance of the scale of modelling both spatially and temporally.

scholarly journals Haze in Singapore – source attribution of biomass burning PM<sub>10</sub> from Southeast Asia

2019 ◽  
Vol 19 (8) ◽  
pp. 5363-5385 ◽  
Author(s):  
Ayoe Buus Hansen ◽  
Claire Suzanne Witham ◽  
Wei Ming Chong ◽  
Emma Kendall ◽  
Boon Ning Chew ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Southeast Asia ◽  
Biomass Burning ◽  
Dispersion Model ◽  
Source Region ◽  
Atmospheric Dispersion ◽  
Weather Conditions ◽  
Peninsular Malaysia ◽  
Maritime Continent ◽  
Source Regions

Abstract. This paper presents a study of haze in Singapore caused by biomass burning in Southeast Asia over the 6-year period from 2010 to 2015, using the Numerical Atmospheric-dispersion Modelling Environment (NAME), which is a Lagrangian dispersion model. The major contributing source regions to the haze are identified using forwards and backwards model simulations of particulate matter. The coincidence of relatively strong southeast monsoonal winds with increased biomass burning activities in the Maritime Continent create the main Singapore haze season from August to October (ASO), which brings particulate matter from varying source regions to Singapore. Five regions are identified as the dominating sources of pollution during recent haze seasons: Riau, Peninsular Malaysia, South Sumatra, and Central and West Kalimantan. In contrast, off-season haze episodes in Singapore are characterised by unusual weather conditions, ideal for biomass burning, and contributions dominated by a single source region (different for each event). The two most recent off-season haze events in mid-2013 and early 2014 have different source regions, which differ from the major contributing source regions for the haze season. These results challenge the current popular assumption that haze in Singapore is dominated by emissions/burning from only Indonesia. For example, it is shown that Peninsular Malaysia is a large source for the Maritime Continent off-season biomass burning impact on Singapore. The results demonstrate that haze in Singapore varies across year, season, and location and is influenced by local and regional weather, climate, and regional burning. Differences in haze concentrations and variation in the relative contributions from the various source regions are seen between monitoring stations across Singapore, on a seasonal as well as on an inter-annual timescale. This study shows that even across small scales, such as in Singapore, variation in local meteorology can impact concentrations of particulate matter significantly, and it emphasises the importance of the scale of modelling both spatially and temporally.

scholarly journals A fifteen year record of CO emissions constrained by MOPITT CO observations

2016 ◽  
Author(s):  
Zhe Jiang ◽  
John R. Worden ◽  
Helen Worden ◽  
Merritt Deeter ◽  
Dylan B. A. Jones ◽  
...  
Keyword(s):  
Southeast Asia ◽  
Northern Hemisphere ◽  
Biomass Burning ◽  
The United States ◽  
Remotely Sensed ◽  
Positive Trend ◽  
Model Errors ◽  
Remotely Sensed Data ◽  
The Past ◽  
Methyl Chloroform

Abstract. Long-term measurements from satellites and surface stations have demonstrated a decreasing trend of tropospheric carbon monoxide (CO) in the Northern Hemisphere over the past decade. Likely explanations for this decrease include changes in anthropogenic, fires, and/or biogenic emissions or changes in the primary chemical sink hydroxyl radical (OH). Using remotely sensed CO measurements from the Measurement of Pollution in the Troposphere (MOPITT) satellite instrument, in-situ methyl chloroform (MCF) measurements from World Data Centre for Greenhouse Gases (WDCGG), and the adjoint of the GEOS-Chem model, we estimate the change in global CO emissions from 2001–2015. We show that the loss rate of MCF varies by 0.2 % in the past 15 years, indicating that changes in global OH distributions do not explain the recent decrease in CO. Our two-step inversion approach for estimating CO emissions is intended to mitigate the effect of bias errors in the MOPITT data as well as model errors in transport and chemistry, which are the primary uncertainties when quantifying CO emissions using these remotely sensed data. Our results confirm that the decreasing trend of tropospheric CO in the Northern Hemisphere is due to decreasing CO emissions from anthropogenic and biomass burning sources. In particular, we find decreasing CO emissions from the United States and China in the past 15 years, unchanged anthropogenic CO emissions from Europe since 2008, and likely a positive trend from India and southeast Asia, in contrast to recently reported results. We find decreasing trends of biomass burning CO emissions from boreal North America, boreal Asia and South America, but little change over Africa. The inconsistency between our analysis with recent study suggests more efforts are needed for robust conclusion about the variation of anthropogenic CO emissions for India and Southeast Asia.

scholarly journals Impacts of air pollutants from fire and non-fire emissions on the regional air quality in Southeast Asia

2017 ◽  
Author(s):  
Hsiang-He Lee ◽  
Oussama Iraqui ◽  
Yefu Gu ◽  
Hung-Lam Steve Yim ◽  
Apisada Chulakadabba ◽  
...  
Keyword(s):  
Air Quality ◽  
Southeast Asia ◽  
Biomass Burning ◽  
Fossil Fuel ◽  
Anthropogenic Sources ◽  
Fire Emissions ◽  
Fossil Fuel Burning ◽  
Fuel Burning ◽  
Particulate Pollutants ◽  
Low Visibility

Abstract. Severe haze events in Southeast Asia caused by particulate pollution have become more intense and frequent in recent years, degrading air quality, threatening human health, and interrupting economic and societal activities. Widespread biomass burning activities are a major source of severe haze events in Southeast Asia. On the other hand, particulate pollutants from human activities other than biomass burning also play an important role in degrading air quality in Southeast Asia. In this study, numerical simulations have been conducted using the Weather Research and Forecasting (WRF) model coupled with a chemistry component (WRF-Chem) to quantitatively examine the contributions of aerosols emitted from fire (i.e., biomass burning) versus non-fire (including fossil fuel combustion, road and industrial dust, land use, and land change, etc.) sources to the degradation of air quality and visibility over Southeast Asia. These simulations cover a time period from 2002 to 2008 and were respectively driven by emissions from: (a) fossil fuel burning only, (b) biomass burning only, and (c) both fossil fuel and biomass burning. Across ASEAN 50 cities, these model results reveal that 39 % of observed low visibility days can be explained by either fossil fuel burning or biomass burning emissions alone, a further 20 % by fossil fuel burning alone, a further 8 % by biomass burning alone, and a further 5 % by a combination of fossil fuel burning and biomass burning. The remaining 28 % of observed low visibility days remain unexplained, likely due to emissions sources that have not been accounted for. Further analysis of 24-hr PM2.5 Air Quality Index (AQI) indicates that comparing to the simulated result of the case with stand-alone non-fire emissions, the case with coexisting fire and non-fire PM2.5 can substantially increase the chance of AQI being in the moderate or unhealthy pollution level from 23 % to 34 %. The premature mortality among major Southeast Asian cities due to degradation of air quality by particulate pollutants is estimated to increase from ~ 4110 per year in 2002 to ~ 6540 per year in 2008. In addition, we demonstrate the importance of certain missing non-fire anthropogenic aerosol sources including anthropogenic fugitive and industrial dusts in causing urban air quality degradation. An exploratory experiment of using machine learning algorithms to forecasting the occurrence of haze events in Singapore is also demonstrated in this study. All these results suggest that besides minimizing biomass burning activities, an effective air pollution mitigation policy for Southeast Asia needs to consider controlling emissions from non-fire anthropogenic sources.

Biomass burning-derived airborne particulate matter in Southeast Asia: A critical review

2021 ◽  
Vol 407 ◽  
pp. 124760
Author(s):  
Max G. Adam ◽  
Phuong T.M. Tran ◽  
Nanthi Bolan ◽  
Rajasekhar Balasubramanian
Keyword(s):  
Particulate Matter ◽  
Southeast Asia ◽  
Biomass Burning ◽  
Critical Review ◽  
Airborne Particulate Matter ◽  
Airborne Particulate
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