Biogeochemistry Department, Max Planck Institute for Chemistry, Mainz 55020, Germany.
Science. 2011 Sep 16;333(6049):1616-8. doi: 10.1126/science.1207687. Epub 2011 Aug 18.
Hydroxyl radicals (OH) are a key species in atmospheric photochemistry. In the lower atmosphere, up to ~30% of the primary OH radical production is attributed to the photolysis of nitrous acid (HONO), and field observations suggest a large missing source of HONO. We show that soil nitrite can release HONO and explain the reported strength and diurnal variation of the missing source. Fertilized soils with low pH appear to be particularly strong sources of HONO and OH. Thus, agricultural activities and land-use changes may strongly influence the oxidizing capacity of the atmosphere. Because of the widespread occurrence of nitrite-producing microbes, the release of HONO from soil may also be important in natural environments, including forests and boreal regions.
羟基自由基（OH）是大气光化学反应中的关键物种。在低层大气中，高达约 30%的初级 OH 自由基生成归因于亚硝酸（HONO）的光解，而现场观测表明存在大量的 HONO 缺失源。我们表明土壤亚硝酸盐可以释放 HONO，并解释了报告中缺失源的强度和日变化。pH 值较低的施肥土壤似乎是 HONO 和 OH 的特别强的来源。因此，农业活动和土地利用变化可能会强烈影响大气的氧化能力。由于产生亚硝酸盐的微生物广泛存在，HONO 从土壤中的释放也可能在包括森林和北方地区在内的自然环境中很重要。
