Acyl peroxynitrates are formed in the atmosphere through the oxidation of NO_x and are treated as temporary NO_x sinks because they typically decompose to rerelease NO_x on the time scale of a few hours. Canopy and leaf level measurements of acyl peroxynitrate deposition to vegetation, however, have revealed that this removal process is rapid and may compete with chemical decomposition. In an effort to learn more about the dry deposition of acyl peroxynitrates, we designed experiments to measure the deposition of peroxyacetyl nitrate and peroxypropionic nitrate to ten California-native tree species. The deposition of these two organic nitrate compounds was driven by leaf stomatal uptake. No surface deposition of either nitrate was observed. Maximum deposition velocities ranged from 0.09–0.3 cm s^–1 and correlated strongly with maximum leaf stomatal conductance. The stomatal uptake of peroxyacetyl nitrate and peroxypropionic nitrate scaled with factors of 0.73 ± 0.03 and 0.95 ± 0.07, respectively, of the stomatal limit independent of water and nitrogen status of the trees. These measurements suggest that the uptake of acyl peroxynitrates by leaf stomata can be a dominant loss process in areas of high tree cover and moderate temperature.

中文翻译：

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叶片过气硝酸盐干沉积在树木上的气孔控制

通过NO的氧化而形成的酰基peroxynitrates在大气中_X和被视为临时NO _X水槽，因为它们通常分解以重新发布NO _X在几个小时的时间范围内。冠层和叶片水平的过氧化硝酸酰基酯沉积到植物的测量结果表明，该去除过程非常迅速，并且可能与化学分解竞争。为了更多地了解酰基过氧硝酸酯的干式沉积，我们设计了一些实验来测量过氧乙酰硝酸盐和过氧丙酸硝酸盐在十种加利福尼亚本土树种上的沉积。这两种有机硝酸盐化合物的沉积是由叶片气孔吸收驱动的。没有观察到任何硝酸盐的表面沉积。最大沉积速度范围为0.09–0.3 cm s ^–1与最大叶片气孔导度密切相关。过氧乙酰硝酸盐和过氧丙酸硝酸盐的气孔吸收分别取决于气孔极限的因子0.73±0.03和0.95±0.07，与树木的水和氮状况无关。这些测量结果表明，在高树木覆盖率和中等温度的地区，叶片气孔对酰基过氧硝酸盐的吸收可能是一个主要的损失过程。