Observation of atmospheric nitrous acid with DOAS in Beijing, China.
Measurements of nitrous acid (HONO) and nitrogen dioxide (NO2) in Beijing City have been performed by means of a developed differential optical absorption spectroscopy (DOAS) system based on photodiode array (PDA), during the autumn of 2004. HONO and NO2 were simultaneously identified by their characteristic absorption bands in the spectral region between 337 nm and 372 nm with high sensibility and time resolution. The concentrations of HONO exhibit obviously diurnal variation with a nocturnal maximum and a daytime minimum. The highest HONO value up to 11.8 microg/m3 was observed during the night of 2/3 September. Possible sources of the observed HONO were discussed. Good correlation to NO2 indicates that NO2 is a main source component. The measurement also shows direct emission of HONO is an important source in strongly polluted urban area.
Qin
Min
M
Key Laboratory of Environmental Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China. mqin@aiofm.ac.cn
Xie
Pin-Hua
PH
Liu
Wen-Qing
WQ
Li
Ang
A
Dou
Ke
K
Fang
Wu
W
Liu
Jian-Guo
JG
Zhang
Wei-Jun
WJ
D001272:Atmosphere; D002681:China; D009608:Nitrous Acid / Q000032:analysis*
D009608:Nitrous Acid