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Abundance and Emission Flux of the Anthropogenic Iron Oxide Aerosols From the East Asian Continental Outflow
Author(s) -
Yoshida Atsushi,
Ohata Sho,
Moteki Nobuhiro,
Adachi Kouji,
Mori Tatsuhiro,
Koike Makoto,
Takami Akinori
Publication year - 2018
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1029/2018jd028665
Subject(s) - aerosol , flux (metallurgy) , atmospheric sciences , mass concentration (chemistry) , environmental science , environmental chemistry , chemistry , geology , organic chemistry
Anthropogenic iron oxide (FeO x ) aerosols can affect atmospheric radiation, marine biogeochemistry, and human health. However, due to lack of observational data, their atmospheric abundance and emission flux are not well understood. In this study, we observed size‐resolved concentrations of FeO x (170–2100 nm) and black carbon (BC, 70–850 nm) aerosols at a remote site in the East China Sea in March 2016 using a modified single‐particle soot photometer (SP2). Light signals measured by the SP2 and particle morphology and compositions analyzed by a transmission electron microscope revealed that most of the observed FeO x aerosols are of anthropogenic origin. Clear correlations were found between mass concentrations of FeO x and BC ( R 2 = 0.717) and between FeO x and carbon monoxide (CO) ( R 2 = 0.718) in air masses from China, indicating that their emission sources are spatially similar. The correlation slopes of mass concentration (ng/m 3 ) are ~0.3 and 0.0015, respectively. Based on the correlation slopes and emission inventories of BC and CO in China, we estimated emission flux of anthropogenic FeO x aerosols from China to be 0.21–0.49 FeTg/yr. Based on the observed size distribution and previous studies on mass fraction of FeO x and non‐FeO x , we also estimated emission flux of anthropogenic Fe (FeO x + non‐FeO x ) in PM 10 as 0.74–1.7 FeTg/yr. These emission fluxes from China are comparable to global emission fluxes in currently reported inventories of anthropogenic Fe (0.51–1.91 FeTg/yr). Our results suggest that the current emission inventories of anthropogenic Fe are underestimated.