The direct effects of black carbon aerosols from different source sectors in East Asia in summer

Abstract

Black carbon (BC) aerosol is a significant, short-lived climate forcing agent. To further understand the effects of BCs on the regional climate, the warming effects of BCs from residential, industrial, power and transportation emissions are investigated in Asian regions during summer using the state-of-the-art regional climate model RegCM4. BC emissions from these four sectors have very different rates and variations. Residential and industrial BCs account for approximately 85% of total BC emissions, while power BCs account for only approximately 0.19% in Asian regions during summer. An investigation suggests that both the BC aerosol optical depth (AOD) and direct radiative forcing (DRF) are highly dependent on emissions, while the climate effects show substantial nonlinearity to emissions. The total BCs AOD and clear-sky top of the atmosphere DRF averaged over East Asia (100-130°E, 20-50°N) are 0.02 and + 1.34 W/m 2 , respectively, during summer. Each sector's BC emissions may result in a warming effect over the region, leading to an enhanced summer monsoon circulation and a subsequent local decrease (e.g., northeast China) or increase (e.g., south China) in rainfall in China and its surrounding regions. The near surface air temperature increased by 0.2 K, and the precipitation decreased by approximately 0.01 mm/day in east China due to the total BC emissions. The regional responses to the BC warming effects are highly nonlinear to the emissions, which may be linked to the influences of the perturbed atmospheric circulations and climate feedback. The nonuniformity of the spatial distribution of BC emissions may also have significant influences on climate responses, especially in south and east China. The results of this study could aid us in better understanding BC effects under different emission conditions and provide a scientific reference for developing a better BC reduction strategy over Asian regions.

Regional and Sectoral Sources for Black Carbon Over South China in Spring and Their Sensitivity to East Asian Summer Monsoon Onset

“…The BC emissions in these two regions are the highest in MAM compared to in other seasons. Res and Ind are the main BC emission sectors in Asia (Zhuang et al, 2019). The BC emissions from the other anthropogenic sectors, including Tra, Agr, and Ene, are much lower and attain their highest values in eastern China and northern India (Li, Liao, et al, 2016; Wang et al, 2012).…”

“…The emission sensitivity approach and BC‐tagging technique applied in the model are two widely used methods to analyze BC sources in large areas for long periods (Li, Liao, et al, 2016; Wang, Rasch, Easter, et al, 2014; Zhang, Wang, Hegg, et al, 2015; Zhang, Wang, Qian, et al, 2015; Zhuang et al, 2019). Compared with the former method, which requires multiple emission perturbation simulations, the BC‐tagging technique generates more computational and accurate results when identifying BC sources (Wang, Rasch, Easter, et al, 2014).…”

Source apportionment of black carbon aerosols from light absorption observation and source-oriented modeling: an implication in a coastal city in China

“…Black carbon (BC) aerosol is a vital air pollutant throughout the surface earth system and has attracted great concern regarding its multiple impacts on human health, climate change and atmospheric visibility (Bond et al, 2013;Zhuang et al, 2018Zhuang et al, , 2019Chen et al, 2020). As the most important light-absorbing component of PM 2.5 (particulate matters with aerodynamic diameter less than 2.5 µm), BC exerts a key and unique role in the climate system by absorbing solar radiation, affecting chemical/physical properties of cloud and influencing snow and ice cover (Jacobson, 2002;Ramanathan and Carmichael, 2008;Bond et al, 2013;Qian et al, 2014;Kim et al, 2015).…”

Long-Term Variation of Black Carbon Absorption Aerosol Optical Depth from AERONET Data over East Asia

“…Several studies have reported similar seasonal trends of BC concentrations (lowest in summer, highest in winter) at Chinese sites [68,69]. Zhuang et al [70] found considerable seasonal variations in BC emissions over East Asia, predominantly driven by changing domestic and residential emissions. Kang et al [71] attributed increased AAOD over the North China Plain and the Korean Peninsula during winter to seasonal increases of BC and organic carbon (OC) emissions.…”