Abstract
Abstract. The relationship between hygroscopic properties and chemical characteristics of Indonesian biomass burning (BB) particles, which are dominantly generated from peatland fires, was investigated using a humidified tandem differential mobility analyzer. In addition to peat, acacia (a popular species at plantation) and fern (a pioneering species after disturbance by fire) were used for experiments. Fresh Indonesian peat burning particles are almost non-hygroscopic (mean hygroscopicity parameter, κ < 0.06) due to predominant contribution of water-insoluble organics. The range of κ spans from 0.02 to 0.04 (dry diameter = 100 nm, hereinafter) for Riau peat burning particles, while that for Central Kalimantan ranges from 0.05 to 0.06. Fern combustion particles are more hygroscopic (κ = 0. 08), whereas the acacia burning particles have a mediate κ value (0.04). These results suggest that κ is significantly dependent on biomass types. This variance in κ is partially determined by fractions of water-soluble organic carbon (WSOC), as demonstrated by a correlation analysis (R = 0.65). κ of water-soluble organic matter is also quantified, incorporating the 1-octanol–water partitioning method. κ values for the water extracts are high, especially for peat burning particles (A0 (a whole part of the water-soluble fraction): κ = 0.18, A1 (highly water-soluble fraction): κ = 0.30). This result stresses the importance of both the WSOC fraction and κ of the water-soluble fraction in determining the hygroscopicity of organic aerosol particles. Values of κ correlate positively (R = 0.89) with the fraction of m∕z 44 ion signal quantified using a mass spectrometric technique, demonstrating the importance of highly oxygenated organic compounds to the water uptake by Indonesian BB particles. These results provide an experimentally validated reference for hygroscopicity of organics-dominated particles, thus contributing to more accurate estimation of environmental and climatic impacts driven by Indonesian BB particles on both regional and global scales.
Highlights
In Southeast Asia, tropical peatland fires, which occur by combustion of both peat and vegetation, have become frequent during the last few decades (van der Werf et al, 2010; Reddington et al, 2014; Marlier et al, 2015; Spracklen et al, 2015; Stockwell et al, 2016)
The ToF-ACSM and organic carbon (OC)–elemental carbon (EC) data (Table 3) demonstrate that chemical composition of submicron biomass burning particles is dominated by organic species, accounting for approximately 99 % in mass (Budisulistiorini et al, 2017)
The variation in hygroscopic properties is attributed to differences in organic chemical composition, as these biomass burning particles contain negligible fractions of inorganic ionic species (Budisulistiorini et al, 2017)
Summary
In Southeast Asia, tropical peatland fires, which occur by combustion of both peat and vegetation, have become frequent during the last few decades (van der Werf et al, 2010; Reddington et al, 2014; Marlier et al, 2015; Spracklen et al, 2015; Stockwell et al, 2016). Water uptake properties of biomass burning particles, including those emitted from peatlands, have been explored in a laboratory through measurements of hygroscopic growth and CCN activity (Chand et al, 2005; Dusek et al, 2005, 2011; Day et al, 2006; Petters et al, 2009; Carrico et al, 2010). This method provides a new angle (i.e., water solubility) to characterize chemical properties of WSOM, facilitating a more detailed investigation of particle water uptake properties with the first application of the method in HTDMA measurements of a highly hydrophilic organic fraction These data were synergistically combined to provide a detailed picture of water uptake properties of freshly emitted Indonesian peatland burning particles
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
