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

Abstract

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.

Experience from Integrated Air Quality Management in the Mexico City Metropolitan Area and Singapore

“…The scientific work on transboundary pollution has focused on determining the physical and chemical characteristics of the peat-burning particles that reach Singapore during haze episodes [169][170][171][172][173] and the personal exposure and potential health risk that they pose [174][175][176]. Similarly, a few studies have applied modeling techniques to evaluate the impact of such fires over Singapore and other locations within the region [177][178][179][180].…”

Evaluation and sensitivity analysis of the ecosystem service functions of haze absorption by green space based on its quality in China

“…There are two main aspects of haze production. The first includes human factors such as automobile exhaust, coal waste gas, industrial emissions, construction and road traffic dust, climate change, waste incineration, and even volcanic eruptions (Hansen et al 2019). The role of different sources of pollution varies in different haze regions.…”

The Influence of South East Asia Forest Fires on Ambient Particulate Matter Concentrations in Singapore: An Ecological Study Using Random Forest and Vector Autoregressive Models

“…Haze was also shown to be worse in El Niňo years [26]. In addition, a study in Singapore demonstrated that haze fluctuates according to localities and seasons and is also influenced by factors such as weather parameters and the extent of burning in the neighboring regions [10].…”

“…Haze, generated by biomass burning, causes air pollution that affects local air quality as well as the air quality of distant places. Haze can have detrimental impacts on human health [4][5][6][7][8], climate, biodiversity, tourism and agricultural production [9] as well as degrade visibility [10].…”

“…In recent decades, biomass burning has become a recurring phenomenon in mainland Southeast Asia (SEA) and the islands of Sumatra and Borneo [10][11][12][13][14]. The majority of biomass burning in Southeast Asia occur due to human initiated activities such as land clearing for oil palm plantations, other causes of deforestation, poor peatland management, and burning of agriculture waste [15,16].…”