Variation of black carbon in Northeast China based on ground observation and MERRA-2 reanalysis data

• Published in: E3S web of conferences Vol. 194; p. 4061
• Main Authors: Song, Qingli, Li, Yanan, Yu, Dajiang, Zhao, Jinrong, Li, Zhou, Zhang, Yong
• Format: Journal Article
• Language: English
• Published: EDP Sciences 01.01.2020
• ISSN: 2267-1242; 2267-1242
• DOI: 10.1051/e3sconf/202019404061

The temporal variations of black carbon concentration at 7 sites, including Longfengshan, Anshan, Benxi, Dalian, Changchun, Shenyang, and Fushun, in Northeast China was studied based on up to 11 years of ground observations and MERRA-2 reanalysis dataset. Except for Benxi, Changchun and Shenyang, at other four sites, the ground-based black carbon concentrations have decreased generally in the last decade, while changes in the black carbon concentration of MERRA-2 are relatively small. The seasonality of measured black carbon concentration shows a trend of low in May-June and high in January at all sites, and the diurnal cycles present similar pattern with two peaks occurring at 10:00-12:00 UTC and 23:00-24:00 UTC respectively, two troughs occurring at 05:00-07:00 UTC and 19:00-20:00 UTC respectively. The daily mean of MERRA-2 black carbon concentration is 49.3% lower than that of the ground observations at 7 sites averagely. They also show poor consistency in terms of seasonal and daily changes, which perhaps means an inappropriate application of MERRA-2 black carbon concentration at single point in Northeast China.