Size-resolved chemical composition, effective density, and optical properties of biomass burning particles
| Autor: | Hong Chen, Ci Zhang, Jinghao Zhai, Xin Yang, Jianmin Chen, Qi Zhang, Xiaohui Lu, Ling Li |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Atmospheric Science
Range (particle radiation) 010504 meteorology & atmospheric sciences Chemistry Potassium Analytical chemistry Mixing (process engineering) chemistry.chemical_element Carbon black 010501 environmental sciences medicine.disease_cause 01 natural sciences Soot lcsh:QC1-999 Aerosol lcsh:Chemistry lcsh:QD1-999 medicine Absorption (electromagnetic radiation) Chemical composition lcsh:Physics 0105 earth and related environmental sciences |
| Zdroj: | Atmospheric Chemistry and Physics, Vol 17, Pp 7481-7493 (2017) |
| ISSN: | 1680-7324 1680-7316 |
| Popis: | Biomass burning aerosol has an important impact on the global radiative budget. A better understanding of the correlations between the mixing states of biomass burning particles and their optical properties is the goal of a number of current studies. In this work, the effective density, chemical composition, and optical properties of rice straw burning particles in the size range of 50–400 nm were measured using a suite of online methods. We found that the major components of particles produced by burning rice straw included black carbon (BC), organic carbon (OC), and potassium salts, but the mixing states of particles were strongly size dependent. Particles of 50 nm had the smallest effective density (1.16 g cm−3) due to a relatively large proportion of aggregate BC. The average effective densities of 100–400 nm particles ranged from 1.35 to 1.51 g cm−3 with OC and inorganic salts as dominant components. Both density distribution and single-particle mass spectrometry showed more complex mixing states in larger particles. Upon heating, the separation of the effective density distribution modes confirmed the external mixing state of less-volatile BC or soot and potassium salts. The size-resolved optical properties of biomass burning particles were investigated at two wavelengths (λ = 450 and 530 nm). The single-scattering albedo (SSA) showed the lowest value for 50 nm particles (0.741 ± 0.007 and 0.889 ± 0.006) because of the larger proportion of BC content. Brown carbon played an important role for the SSA of 100–400 nm particles. The Ångström absorption exponent (AAE) values for all particles were above 1.6, indicating the significant presence of brown carbon in all sizes. Concurrent measurements in our work provide a basis for discussing the physicochemical properties of biomass burning aerosol and its effects on the global climate and atmospheric environment. |
| Databáze: | OpenAIRE |
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