Title: Review of Li et al. Observation of regional air pollutant transport between the megacity Beiing and the North China plain
Abstract: The authors presented an analysis of the regional transport flux of pollutants between Beijing and North China Plain (NCP) based on two years measurements at a single ground site (Yufa) located between the two regions.They also discussed a range of factors that contributed to the pollutant transport.The manuscript is concise and clear.However, the paper has major structure problems.While only four figures are included, the main text has extensive discussions on figures from the supplementary materials.Supplements are meant to provide information to readers, which is not key component to complete the paper.The authors need to reconsider what figures to include in the main text and avoid long discussions on supplements.