Characterization of light-absorbing carbon particles at three altitudes in East Asian outflow by transmission electron microscopy

摘要: Abstract. The morphology, microstructure, and composition of the submicron fraction individual light-absorbing carbon (LAC) particles collected by research aircraft during ACE-Asia (Asian Pacific Regional Aerosol Characterization Experiment) project above Yellow Sea at altitudes 120, 450 1500 m are investigated transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS). Two types carbonaceous particles, small spherule soot with graphitic spherules amorphous spheres (brown carbon), found all in high concentration. For emphasis study is on component subparticles (spherules). nanoscopic structures show no significant difference three although size distribution primary showed that 70% total volume lies ranges 30–50, 50–85 30–50 nm, respectively. spheres, from range 200–350, 160–470 150–320 Within studied (submicron, most 50 to 500 nm) number concentration ratios about 1, 1.5 10, respectively their 260, 1400. Lower relative concentrations large intermediate structure were observed 120 m. Also, low cenospheres A key result vertically stratified outflow East Asia, character LAC may have strong variance altitude thus resulting optical characteristics vary altitude. apparent "aging" deduced samples multiple ground stations instead reflect differences original aerosols.