Uncertainty in the uptake coefficient for HONO formation on soot and its impacts on concentrations of major chemical components in the Beijing-Tianjin-Hebei region

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• 作者：Yujia Tang ; Junling An ; Ying Li ; Feng Wang
• 关键词：Soot ; HONO ; Uptake coefficient ; WRF-Chem model
• 刊名：Atmospheric Environment
• 出版年：February, 2014
• 年：2014
• 卷：84
• 期：Complete
• 页码：163-171
• 全文大小：3512 K

文摘

The soot redox reaction with an uptake coefficient (纬) of 10^鈭? at night and the soot heterogeneous photochemistry with the 纬 formula of J_NO2/10 in the daytime, where J_NO2 denotes the NO₂ photolysis frequency, were inserted into the WRF-Chem model to evaluate the effects of 纬 changes of several orders of magnitude on the concentrations of HONO, HO_x, O₃, NO₃^{鈭?/sup>, and NH₄+ in the Beijing-Tianjin-Hebei (BTH) region. Results demonstrated that the simulations in the BTH region support the redox mechanism at night and the heterogeneous photochemistry mechanism in the daytime for HONO formation, and suggested that the order of magnitude of 纬 is likely to be 10鈭?. Minor increases in HONO, HO_x, O₃, NO₃鈭?/sup>, and NH₄+ were produced when 纬 was decreased to 鈮?0鈭?, whereas the concentrations of HONO and NO₃鈭?/sup> were substantially overestimated in most cases when 纬 was increased to 10鈭?. The soot surface area per unit volume of air showed a sharp decrease from 3 脳 103 渭m2 cm鈭? near the ground to 6 脳 102 渭m2 cm鈭? at 鈭?00 m at night. The surface area fractions of soot, nitrate, and sulfate showed minor variations between day and night, although the surface areas of the major aerosol components at night were approximately three times those in the daytime.}