Effects of biomass burning on CO, HCN, C2H6, C2H2 and H2CO during long-term FTIR measurements in Hefei, China.

High-resolution solar absorption spectra were continuously collected by a ground-based Fourier transform infrared (FTIR) spectrometer to retrieve the total column of carbon monoxide (CO), hydrogen cyanide (HCN), ethane (C2H6), acetylene (C2H2), and formaldehyde (H2CO). The time series and variation characteristics of these gases were analyzed. The biomass combustion process is identified by using the correlations between the monthly mean deviations of HCN, C2H6, C2H2 and H2CO versus CO and satellite fire point data. The months with high correlation coefficients (R > 0.8) and peaks of fire point number are considered to be with biomass combustion occurrence. The emissions of HCN, C2H6, C2H2 and H2CO in Anhui were estimated using the enhancement ratios of gases to CO in these months when biomass combustion was the main driving factor of gas concentration change. The study proved the ability of FTIR system in inferring the period during biomass combustion and estimating emissions of the trace gases concerning biomass combustion.