Evaluating the sources characteristics of measured oxygenated volatile organic compounds using factor analysis

Trace gases measured in TRACE-P and PEM-Tropics B are analyzed to identify and quantify air masses contributing to the tracers' variability, particularly that of oxygenated volatile organic compounds (OVOCs). The positive matrix factorization (PMF) is applied to the 10 chemical tracers (CH3Cl, CH3OH, CH3COCH3, CH3CHO, C2H2, C2H6, C3H8, CO, CO2, and CHBr3) and recently available tracers, HCN and CH3CN for TRACE-P. The identified characteristics of air masses (factors) are biogenic, biomass burning, oceanic, and industrial sources. The variability of each tracer contributed by each factor is estimated and compared with global fractions of OVOCs by former studies. The biogenic source explains 77 – 82 % of CH3OH variability and 11 – 14% of CH3CHO variability. In particular, the significant variability of acetone (38%) and HCN (43%) from biogenic source implies that the impact of cyanogenesis in plants on Asian outflow is substantial. More than an order of magnitude higher variability by industrial source for industrial tracers of TRACE-P confirms the characteristic of highly-polluted Asian outflow in spring.