Radiocarbon-based carbon source apportionment of black carbon and organic carbon in carbonaceous aerosols in Asian outflow
Dr Masao Uchida1, Hidetoshi Kumata2, Naoki Kaneyasu3, Kanako Mantoku1, Daishi Handa4, Takemitsu Arakaki4, Kimitaka Kawamura5, Yasuyuki Shibata1
1National Institute For Environmental Studies, Tsukuba, Japan, 2Tokyo University of Pharmacy and Life Sciences, Tokyo, Japan, 3National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan, 4University of the Ryukyus, Nishihara, Japan, 5Chubu University, Kasugai, Japan
Analysis of radiocarbon in carbonaceous aerosols allows an apportionment of fossil and non-fossil (biomass and biogenic) sources of airborne particulate matter. We measured the ¹⁴C content of black carbon (BC), organic carbon and total carbon in PM2.5 and PM10 aerosols collected from 2008 to 2010 at Fukue Island and Cape Hedo on Okinawa Island in the East China Sea to investigate the sources of BC from China and surroundings. We also conducted back-trajectory analyses for each sampling period to ascertain the source regions of BC. The results showed that on average, approximately 60% of the air masses at both sites were delivered from the Asian continent, but results from two sites had no apparent relation to the concentrations or ¹⁴C contents of BC. However, the trajectory maps suggest some relationships between BC source regions and ¹⁴C content of BC at both sites. Our data from Fukue showed relatively large contributions of biomass burning in mid-winter, and back-trajectory analyses suggest that the source area was as distant as Mongolia or Siberia, which showed a clear difference in aerosol sources for the two sites.
My research interests include developing and improving isotope proxies and various analytical methods and techniques, especially for compound-specific radiocarbon analysis and microscale radiocarbon analysis. For examples, those proxies are strong tool for deciphering fate and origin of biogeochemical carbon cycles and environmental pollutants in the modern and past environment realm.