Investigation of the wet removal rate of black carbon in East Asia: validation of a below- and in-cloud wet removal scheme in FLEXible PARTicle (FLEXPART) model v10.4

Abstract. Understanding the global distribution of atmospheric black carbon (BC) is essential to unveil its climatic effect. However, there are still large uncertainties regarding the simulation of BC transport due to inadequate information about the removal process. We accessed the wet removal rate of BC in East Asia based on long-term measurements over the 2010–2016 period at three representative background sites (Baengnyeong and Gosan in South Korea and Noto in Japan). The average wet removal rate, represented by transport efficiency (TE), i.e. the fraction of undeposited BC particles during transport, was estimated as 0.73 in East Asia from 2010 to 2016. According to accumulated precipitation along trajectory, TE was lower in East and North China, where the industrial sector (thin-coated) is dominant; in contrast, that in South Korea and Japan showed higher values due to the transpor…