Coating chimney flues and diesel exhaust pipes, black carbon leaves a sooty footprint on Earth. But how to track its travel through the atmosphere?
Scientists at Pacific Northwest National Laboratory developed a unique computational tagging technique to detect the influence of local vs. non-local sources of soot on China's regional air quality. They used this technique to determine how much each soot source—local or remote—contributed to atmospheric warming over China. Atmospheric Chemistry and Physics published the research.
[...] In regions of China with strong black carbon emissions—for example, the north, south, and northeast—researchers found that local sources predominantly contributed to near-surface black carbon concentrations. Scientists also discovered that non-local sources more strongly influenced black carbon over central and western China. During the winter haze season, more than 50 percent of near-surface black carbon in China originated from pollution in north China, which contributed more than 90 percent to local black carbon and a substantial amount to south, southwest, and central-west China. Overall, local sources accounted for 65 percent of black carbon's atmospheric heating over China, while outside sources contributed 35 percent.
The study also showed that China's soot doesn't stay within its borders. Air pollution from China, via transport over the Pacific Ocean, accounted for 8 percent of black carbon concentration and 29 percent of the total air column load of black carbon in the Western United States in spring.
Air pollution in China doesn't come from industrial complexes in Siberia?