Characteristics of MERRA-2 Black Carbon in Eight Key Climatic Regions across China from 2007 to 2018

摘要

The spatial distribution, temporal variations and trend changes of surface black carbon concentrations in eight key climatic regions across China were analyzed from 2007 to 2018, based on the Modern-era Retrospective Analysis for Research and Applications Version 2 (MERRA-2) black carbon dataset. The mass concentration of BC in China shows an “East-High and West-Low” pattern, with multi-year averaged BC ranging from 154 ng/m~(3)to 3857 ng/m~(3). Pronounced seasonal variations were found, with the highest value in winter and the lowest in summer. Most of regions in central and eastern China share similar diurnal pattern with a single-peak at early morning and a valley at noon. Obvious downward trend in most regions of China were identified from 2007 to 2018, especially in southern central China and southwestern part of eastern China, with the highest decline rate of -8.349 ng/m~(3)per month, which confirming that the great endeavors and effective enforcement of environmental protection measures implemented in China for the last decade.