Abundance and Emission Flux of the Anthropogenic Iron Oxide Aerosols From the East Asian Continental Outflow. Issue 19 (9th October 2018)

• Record Type: Journal Article
• Authors: Yoshida, Atsushi; Ohata, Sho; Moteki, Nobuhiro; Adachi, Kouji; Mori, Tatsuhiro; Koike, Makoto; Takami, Akinori
• Is Part Of: Journal of geophysical research. Volume 123:Issue 19(2018)
• Page Start: 11, 194
• Page End: 11, 209
• Publication Date: 2018-10-09
• Subjects: aerosols -- iron oxide -- emission -- East Asia -- single‐particle soot photometer; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1029/2018JD028665
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: 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 PM10 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. Key Points: Anthropogenic iron oxide (FeO x ) aerosols are correlated with black carbon and with carbon monoxide in outflow from China ( R 2 > 0.7) Mass concentration of anthropogenic FeO x aerosols from China is approximately 30% of the mass concentration of black carbon Currently reported emission inventories of anthropogenic iron aerosols are likely to be underestimated