Tropospheric cycle of nitrous acid
Tropospheric cycle of nitrous acid
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DOI：
10.1029/96jd00341
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发表时间：
1996-06-20
影响因子：
4.4
通讯作者：
Collins, GM
中科院分区：
文献类型：
--
作者：
Harrison, RM;Peak, JD;Collins, GM
对草地和甜菜表面上亚硝酸的陆地表面交换的测量显示了向上和向下的通量，在二氧化氮的环境浓度约为10 ppb时发生通量反转。这证实了早期的初步发现，并加强了陆地表面二氧化氮和水蒸气反应可以产生大量亚硝酸的假设。在中心城市、郊区和农村环境中对亚硝酸进行了详细的测量。这些测量与一个简单的箱形模型相结合，表明大气中亚硝酸盐的浓度可以用少数基本过程来解释，其中最重要的是二氧化氮在表面产生的亚硝酸盐，NO-OH反应在大气中产生的亚硝酸盐，以及通过光解和干沉积造成的亚硝酸盐损失。在郊区的大气中，亚硝酸盐的浓度与二氧化氮密切相关。在农村大气中，可以看到不同的行为，在二氧化氮浓度超过10 ppb的污染更严重的空气中，硝酸与二氧化氮的比例要高得多。在二氧化氮浓度较低的情况下，地面的硝酸净沉积导致平流空气中的浓度很低。模型研究表明，白天在郊区大气中，由NO-OH反应产生的HONO可以与光解反应相竞争，使HONO浓度达到十亿分之一的零点几。在白天观测到的最高浓度的HONO下，其光解产生OH自由基的速度比臭氧光解快10倍以上。
Measurements of the land surface exchange of nitrous acid over grass and sugar beet surfaces reveal both upward and downward fluxes with flux reversal occurring at an ambient concentration of nitrogen dioxide of about 10 ppb. This confirms earlier preliminary findings and strengthens the hypothesis that substantial production of nitrous acid can occur on land surfaces from reaction of nitrogen dioxide and water vapor. Detailed measurements of nitrous acid have been made in central urban, suburban, and rural environments. These measurements, in conjunction with a simple box model, indicate that the atmospheric concentrations of nitrous acid are explicable in terms of a small number of basic processes in which the most important are the surface production of nitrous acid from nitrogen dioxide, atmospheric production from the NO-OH reaction and loss of nitrous acid by photolysis and dry deposition. In the suburban atmosphere, concentrations of nitrous acid are strongly correlated with nitrogen dioxide. In the rural atmosphere a different behavior is seen, with much higher nitrous acid to nitrogen dioxide ratios occurring in more polluted air with nitrogen dioxide concentrations in excess of 10 ppb. At lower nitrogen dioxide concentrations, net deposition of nitrous acid at the ground leads to very low concentrations in advected air. The model study indicates that during daytime in the suburban atmosphere, production of HONO from the NO-OH reaction can compete with photolysis giving a HONO concentration of a few tenths of a part per billion. At the highest observed daytime concentrations of HONO, production of OH radical from its photolysis can proceed at a rate more than 10 times faster than from photolysis of ozone.