scholarly journals Method to quantify black carbon aerosol light absorption enhancement with a mixing state index

2021 ◽  
Vol 21 (23) ◽  
pp. 18055-18063
Author(s):  
Gang Zhao ◽  
Tianyi Tan ◽  
Yishu Zhu ◽  
Min Hu ◽  
Chunsheng Zhao
Keyword(s):  
Black Carbon ◽  
Light Absorption ◽  
Binary Systems ◽  
Absorption Enhancement ◽  
Mixing State ◽  
Radiative Effects ◽  
State Index ◽  
Black Carbon Aerosol ◽  
Mixing States ◽  
Radiative Absorption

Abstract. Large uncertainties remain when estimating the warming effects of ambient black carbon (BC) aerosols on climate. One of the key challenges in modeling the radiative effects is predicting the BC light absorption enhancement, which is mainly determined by the mass ratio (MR) of non-BC coating material to BC in the population of BC-containing aerosols. For the same MR, recent research has found that the radiative absorption enhancements by BC are also controlled by its particle-to-particle heterogeneity. In this study, the BC mixing state index (χ) is developed to quantify the dispersion of ambient black carbon aerosol mixing states based on binary systems of BC and other non-black carbon components. We demonstrate that the BC light absorption enhancement increases with χ for the same MR, which indicates that χ can be employed as a factor to constrain the light absorption enhancement of ambient BC. Our framework can be further used in the model to study the radiative effects of black carbon on climate change.

scholarly journals Method to Quantify the Black Carbon Aerosol Light Absorption Enhancement with Entropy and Diversity Measures

2021 ◽  
Author(s):  
Gang Zhao ◽  
Tianyi Tan ◽  
Yishu Zhu ◽  
Min Hu ◽  
Chunsheng Zhao
Keyword(s):  
Black Carbon ◽  
Light Absorption ◽  
Binary Systems ◽  
Absorption Enhancement ◽  
Mass Ratio ◽  
Radiative Effects ◽  
State Index ◽  
Black Carbon Aerosol ◽  
Mixing States ◽  
Radiative Absorption

Abstract. Large uncertainties remain when estimating the warming effects of ambient black carbon (BC) aerosols on climate. One of the key challenges in modeling the radiative effects is predicting the BC light absorption enhancement, which is mainly determined by its mass ratio of non-BC coating thickness to BC (MR). For the same MR, recent researches find that the radiative absorption enhancements by BC are also controlled by its particle-to-particle heterogeneity. In this study, the BC mixing state index (χ) is developed to quantify the dispersion of ambient black carbon aerosol mixing states based on binary systems of BC and other non-black carbon components. We demonstrate that the BC light absorption enhancement increases with χ for the same MR, which indicates that χ can be employed as a factor to constrain the light absorption enhancement of ambient BC. Our framework can be further used in the model to study the black carbon radiative effects on climate change.

Mixing State of Black Carbon Aerosol in a Heavily Polluted Urban Area of China: Implications for Light Absorption Enhancement

2014 ◽  
Vol 48 (7) ◽  
pp. 689-697 ◽  
Author(s):  
Qiyuan Wang ◽  
R.-J. Huang ◽  
Junji Cao ◽  
Yongming Han ◽  
Gehui Wang ◽  
...  
Keyword(s):  
Black Carbon ◽  
Urban Area ◽  
Light Absorption ◽  
Absorption Enhancement ◽  
Mixing State ◽  
Black Carbon Aerosol

Mixing state and light absorption enhancement of black carbon aerosols in summertime Nanjing, China

2020 ◽  
Vol 222 ◽  
pp. 117141 ◽  
Author(s):  
Yan Ma ◽  
Congcong Huang ◽  
Halim Jabbour ◽  
Zewen Zheng ◽  
Yibo Wang ◽  
...  
Keyword(s):  
Black Carbon ◽  
Light Absorption ◽  
Absorption Enhancement ◽  
Mixing State ◽  
Carbon Aerosols ◽  
Black Carbon Aerosols

Light absorption of black carbon aerosol and its enhancement by mixing state in an urban atmosphere in South China

2013 ◽  
Vol 69 ◽  
pp. 118-123 ◽  
Author(s):  
Zi-Juan Lan ◽  
Xiao-Feng Huang ◽  
Kuang-You Yu ◽  
Tian-Le Sun ◽  
Li-Wu Zeng ◽  
...  
Keyword(s):  
Black Carbon ◽  
South China ◽  
Light Absorption ◽  
Urban Atmosphere ◽  
Mixing State ◽  
Black Carbon Aerosol

scholarly journals Light Absorption Enhancement of Black Carbon Aerosol Constrained by Particle Morphology

2018 ◽  
Vol 52 (12) ◽  
pp. 6912-6919 ◽  
Author(s):  
Yu Wu ◽  
Tianhai Cheng ◽  
Dantong Liu ◽  
James D. Allan ◽  
Lijuan Zheng ◽  
...  
Keyword(s):  
Black Carbon ◽  
Light Absorption ◽  
Particle Morphology ◽  
Absorption Enhancement ◽  
Black Carbon Aerosol

scholarly journals Implication of Light Absorption Enhancement and Mixing State of Black Carbon (BC) by Coatings in Hong Kong

2018 ◽  
Vol 18 (11) ◽  
pp. 2753-2763 ◽  
Author(s):  
Guo-Liang Li ◽  
Li Sun ◽  
Kin-Fai Ho ◽  
Ka-Chun Wong ◽  
Zhi Ning
Keyword(s):  
Hong Kong ◽  
Black Carbon ◽  
Light Absorption ◽  
Absorption Enhancement ◽  
Mixing State

scholarly journals Strong Light Absorption Induced by Aged Biomass Burning Black Carbon over the Southeastern Tibetan Plateau in Pre-monsoon Season

2020 ◽  
Author(s):  
Tianyi Tan ◽  
Min Hu ◽  
Zhuofei Du ◽  
Gang Zhao ◽  
Dongjie Shang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Black Carbon ◽  
Biomass Burning ◽  
Climate Warming ◽  
Light Absorption ◽  
Monsoon Season ◽  
Absorption Enhancement ◽  
The Tibetan Plateau ◽  
Mixing State ◽  
Strong Light

Abstract. During the pre-monsoon season, biomass burning (BB) activities are intensive in southern Asia. Facilitated by westerly circulation, those BB plumes can be transported to the Tibetan Plateau (TP). Black carbon (BC), the main aerosol species in BB emissions, is an important climate warming agent, and its absorbing property strongly depends on its size distribution and mixing state. To elucidate the influence of those transported BB plumes on the TP, a field campaign was conducted on the southeast edge of the TP during the pre-monsoon season. It was found that the transported BB plumes substantially increased the number concentration of the atmospheric BC particles by 13 times, and greatly elevated the number fraction of thickly-coated BC from 52 % up to 91 %. Those transported BC particles had slightly larger core size and much thicker coatings than the background BC particles. However, the coating mass was not evenly distributed on BC particles with different sizes. The smaller BC cores were found to have larger shell/core ratios than the larger cores. Besides, the transported BB plumes strongly affected the vertical variation of the BC's abundance and mixing state, resulting in a higher concentration, larger number fraction and higher aging degree of BC particles in the upper atmosphere. Resulted from both increase of BC loading and aging degree, the transported BB plumes eventually enhanced the total light absorption by 15 times, in which 21 % was contributed by the BC aging and 79 % was contributed from the increase of BC mass. Particularly, the light absorption enhancement induced by the aging process during long-range transport has far exceeded the background aerosol light absorption, which implicates a significant influence of BC aging on climate warming over the TP region.

scholarly journals Dynamic shape factor and mixing state of refractory black carbon particles in winter in Beijing using an AAC-DMA-SP2 tandem system

2019 ◽  
Author(s):  
Xiaole Pan ◽  
Hang Liu ◽  
Yu Wu ◽  
Yu Tian ◽  
Yele Sun ◽  
...  
Keyword(s):  
Black Carbon ◽  
Light Absorption ◽  
Shape Factor ◽  
Absorption Enhancement ◽  
Urban Site ◽  
Optical Simulation ◽  
Mixing State ◽  
Dynamic Shape Factor ◽  
Dynamic Shape ◽  
Pollution Episodes

Abstract. Refractory black carbon (rBC) is one of the most important short-lived climate forcers in the atmosphere. Light absorption enhancement capacity largely depends on the morphology of rBC-containing particles and their mixing state. In this study, a tandem measuring system, consisting of an aerodynamic aerosol classifier (AAC), a differential mobility analyzer (DMA) and a single particle soot photometer (SP2), was adopted to investigate dynamic shape factor (𝜒) and its relationship with the mixing state of rBC-containing particles at an urban site of Beijing megacity in winter. The results demonstrated that the aerosol particles with an aerodynamic diameter of 400 ± 1.2 nm normally had a mobility diameter (Dmob) ranging from 250 nm to 320 nm, reflecting a large variation in shape under different pollution conditions. Multiple Gaussian fitting on the number mass-equivalent diameter (Dmev) distribution of the rBC core determined by SP2 had two peaks at Dmev = 106.5 nm and Dmev = 146.3 nm. During pollution episodes, rBC-containing particles tended to have a smaller rBC core than those during clean episodes due to rapid coagulation and condensation processes. The 𝜒 values of the particles were found to be ~ 1.2 during moderate pollution conditions, although the shell-core ratio (S/C) of rBC-containing particles was as high as 2.7 ± 0.3, suggesting that the particles had an irregular structure as a result of the high fraction of nascent rBC aggregates. During heavy pollution episodes, the 𝜒 value of the particles was approximately 1.0, indicating that the majority of particles tended to be spherical, and a shell-core model could be reasonable to estimate the light enhancement effect. Considering the variation in shape of the particles, the light absorption enhancement of the particles differed significantly according to the T-matrix model simulation. This study suggested that accurate description of the morphology of rBC-containing particles was crucially important for optical simulation and better evaluation of their climate effect.

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