Abstract
Abstract. The black carbon (BC) and carbon monoxide (CO) emission ratios were estimated and compiled from long-term, harmonized observations of the ΔBC∕ΔCO ratios under conditions unaffected by wet deposition at four sites in East Asia, including two sites in South Korea (Baengnyeong and Gosan) and two sites in Japan (Noto and Fukuoka). Extended spatio-temporal coverage enabled estimation of the full seasonality and elucidation of the emission ratio in North Korea for the first time. The estimated ratios were used to validate the Regional Emission inventory in ASia (REAS) version 2.1 based on six study domains (“East China”, “North China”, “Northeast China”, South Korea, North Korea, and Japan). We found that the ΔBC∕ΔCO ratios from four sites converged into a narrow range (6.2–7.9 ng m−3 ppb−1), suggesting consistency in the results from independent observations and similarity in source profiles over the regions. The BC∕CO ratios from the REAS emission inventory (7.7 ng m−3 ppb−1 for East China – 23.2 ng m−3 ppb−1 for South Korea) were overestimated by factors of 1.1 for East China to 3.0 for South Korea, whereas the ratio for North Korea (3.7 ng m−3 ppb−1 from REAS) was underestimated by a factor of 2.0, most likely due to inaccurate emissions from the road transportation sector. Seasonal variation in the BC∕CO ratio from REAS was found to be the highest in winter (China and North Korea) or summer (South Korea and Japan), whereas the measured ΔBC∕ΔCO ratio was the highest in spring in all source regions, indicating the need for further characterization of the seasonality when creating a bottom-up emission inventory. At levels of administrative districts, overestimation in Seoul, the southwestern regions of South Korea, and Northeast China was noticeable, and underestimation was mainly observed in the western regions in North Korea, including Pyongyang. These diagnoses are useful for identifying regions where revisions in the inventory are necessary, providing guidance for the refinement of BC and CO emission rate estimates over East Asia.
Highlights
Black carbon (BC), emitted from the incomplete combustion of fossil fuel and/or biomass burning, absorbs solar radiation and reduces the surface albedo of snow and ice after dry and wet deposition (Samset, 2018; Bond et al, 2013), thereby augmenting the global warming trend primarily induced by increased levels of carbon dioxide (CO2; Ramanathan and Carmichael, 2008; Jacobson, 2001; Myhre et al, 2013)
The seasonal variation in the BC concentration at all sites showed similar patterns of being low in summer due to rainout followed by precipitation and increasing from fall onwards due to house heating and/or crop biomass burning along with the transition to westerly winds
To verify the Regional Emission inventory in ASia (REAS) bottom-up emission inventory, the BC/ carbon monoxide (CO) ratios were diagnosed from long-term, besteffort observations at four sites in East Asia, including two sites in South Korea (Baengnyeong and Gosan) and two sites in Japan (Fukuoka and Noto)
Summary
Black carbon (BC), emitted from the incomplete combustion of fossil fuel and/or biomass burning, absorbs solar radiation and reduces the surface albedo of snow and ice after dry and wet deposition (Samset, 2018; Bond et al, 2013), thereby augmenting the global warming trend primarily induced by increased levels of carbon dioxide (CO2; Ramanathan and Carmichael, 2008; Jacobson, 2001; Myhre et al, 2013). BC and carbon monoxide (CO) are by-products of the incomplete combustion of carbon-based fuels, and the ratio between BC (the difference from the baseline level) and CO could be a useful parameter for characterizing combustion types Using these characteristics, past studies used the BC/ CO ratio to identify emission source types (Guo et al, 2017; Pan et al, 2011, 2013; Zhu et al, 2019) and/or validate BC emissions from bottom-up inventories (Han et al, 2009; Wang et al, 2011; Verma et al, 2011; Sahu et al, 2009; Kondo et al, 2006). The seasons were limited to autumn–spring, and the footprint over each source region was still limited, as observations at a single site were analyzed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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 call
