Evaluation of MERRA-2 and CAMS reanalysis for black carbon aerosol in China

Weijie Li; Yaqiang Wang; Ziwei Yi; Bin Guo; Wencong Chen; Huizheng Che; Xiaoye Zhang

doi:10.1016/j.envpol.2023.123182

Evaluation of MERRA-2 and CAMS reanalysis for black carbon aerosol in China

Environ Pollut. 2024 Feb 15:343:123182. doi: 10.1016/j.envpol.2023.123182. Epub 2023 Dec 18.

Authors

Weijie Li¹, Yaqiang Wang², Ziwei Yi³, Bin Guo⁴, Wencong Chen⁵, Huizheng Che¹, Xiaoye Zhang¹

Affiliations

¹ State Key Laboratory of Severe Weather & Institute of Artificial Intelligence for Meteorology, Chinese Academy of Meteorological Sciences, Beijing, 100081, China.
² State Key Laboratory of Severe Weather & Institute of Artificial Intelligence for Meteorology, Chinese Academy of Meteorological Sciences, Beijing, 100081, China. Electronic address: yqwang@cma.gov.cn.
³ State Key Laboratory of Severe Weather & Institute of Artificial Intelligence for Meteorology, Chinese Academy of Meteorological Sciences, Beijing, 100081, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
⁴ Department of Atmospheric and Oceanic Sciences & Institute of Atmospheric Sciences, Fudan University, Shanghai, 200433, China.
⁵ Wenzhou Meteorological Bureau, Wenzhou, 325000, China.

PMID: 38123119
DOI: 10.1016/j.envpol.2023.123182

Abstract

Black carbon (BC) constitutes a pivotal component of atmospheric aerosols, significantly impacting regional and global radiation balance, climate, and human health. In this study, we evaluated BC data in two prominent atmospheric composition reanalysis datasets: the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) and the Copernicus Atmosphere Monitoring Service (CAMS), and analyzed the causes of their deviations. This assessment is based on observational data collected from 34 monitoring stations across China from 2006 to 2022. Our research reveals a significant and consistent decline in BC concentrations within China, amounting to a reduction exceeding 67.33%. However, both MERRA-2 and CAMS reanalysis data fail to capture this declining trend. The average annual decrease of BC in MERRA-2 from 2006 to 2022 is only 0.06 μg/m³ per year, while the BC concentration in CAMS even increased with an average annual value of 0.014 μg/m³ per year. In 2022, MERRA-2 had overestimated BC concentration by 20% compared to observational data, while CAMS had overestimated it by approximately 66%. In the regional BC concentration analysis, the data quality of the reanalysis data is better in the South China (R_M = 0.59, R_C = 0.53), followed by the North China (R_M = 0.50, R_C = 0.42). Reanalysis BC data in Northwest China and the Tibetan Plateau are difficult to use for practical analysis due to their big difference with observation. In a comparison of the anthropogenic BC emissions inventory used in the two atmospheric composition reanalysis datasets with the Multi-resolution Emission Inventory model for Climate and air pollution research (MEIC) emissions inventory, we found that: Despite the significant decline in China's BC emissions, MERRA-2 still relies on the 2006 emissions inventory, while CAMS utilizes emission inventories that even show an increasing trend. These factors will undoubtedly lead to greater deviations between reanalysis and observational data.

Keywords: Black carbon; CAMS; China; Emissions inventory; MEIC; MERRA-2.

MeSH terms

Aerosols / analysis
Air Pollutants* / analysis
Atmosphere / analysis
Carbon / analysis
China
Environmental Monitoring
Humans
Retrospective Studies
Soot / analysis

Substances

Air Pollutants
Aerosols
Soot
Carbon