Atmospheric outflow of anthropogenic iron and its deposition to China adjacent seas

Chunqiang Chen; Lei Huang; Jinhui Shi; Yang Zhou; Jiao Wang; Xiaohong Yao; Huiwang Gao; Yayong Liu; Jia Xing; Xiaohuan Liu

doi:10.1016/j.scitotenv.2020.141302

Atmospheric outflow of anthropogenic iron and its deposition to China adjacent seas

Sci Total Environ. 2021 Jan 1:750:141302. doi: 10.1016/j.scitotenv.2020.141302. Epub 2020 Aug 2.

Authors

Chunqiang Chen¹, Lei Huang¹, Jinhui Shi², Yang Zhou³, Jiao Wang¹, Xiaohong Yao², Huiwang Gao², Yayong Liu⁴, Jia Xing⁵, Xiaohuan Liu⁶

Affiliations

¹ Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
² Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Laboratory for Marine Ecology and Environment Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
³ College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao 266100, China.
⁴ State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
⁵ State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: xingjia@tsinghua.edu.cn.
⁶ Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Laboratory for Marine Ecology and Environment Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China. Electronic address: liuxh1983@ouc.edu.cn.

PMID: 32858287
DOI: 10.1016/j.scitotenv.2020.141302

Abstract

Atmospheric deposition of iron (Fe) can increase marine primary productivity, consequently affect ocean biogeochemical cycles and climate change. In this study, we develop an adaptor to generate anthropogenic Fe emission inventories for China in 2012 and 2016 via anthropogenic PM_2.5 emissions from Multi-resolution Emission Inventory for China (MEIC) using local source-specific mass fractions of Fe in PM_2.5. Using the generated emission inventories, we simulated Fe concentrations as well as dry deposition fluxes to China marginal seas using a WRF-CMAQ model during four campaign periods. The simulated Fe concentrations are in good agreement with observations except for those in presence of severe dust-intrusion events (NMB -13% ~ -27%), indicating a reasonably good performance of the generated Fe emissions and leaving the large underestimation of Fe concentrations mainly due to nature dust emissions. Simulated Fe concentrations over China marginal seas are in the range of 62-6.5 × 10² ng m^-3, providing 2.0-12.5 μg m^-2 d^-1 to the seas during the study periods. We also found that inputs of total Fe in PM_2.5 to the seas in presence of dust-intrusion events are 3 and 13 times larger than those in presence of haze events or on less polluted days. Due to lower Fe solubility in nature mineral aerosols than in anthropogenic aerosols, dry deposition fluxes of bioavailable Fe on haze days almost double that in dust days. The total anthropogenic emissions of Fe over China in 2012 and 2016 are estimated as 5.5 × 10² Gg and 3.3 × 10² Gg, respectively. Iron and steel industry are the dominant sources of Fe, accounting for 59-63% of the total anthropogenic Fe emissions. Geotropically, stronger emissions per area were distributed in eastern China, e.g., 2.3 to 15.4 ng m^-2 s^-1 in eastern China versus <0.4 ng m^-2 s^-1 in western China.

Keywords: China marginal seas; Iron deposition; Iron emission inventory; Primary production; WRF-CMAQ.