UV-visible absorption cross sections of nitrous acid
UV-visible absorption cross sections of nitrous acid
复制标题
DOI：
10.1029/2000jd900003
复制
发表时间：
2000-06-16
影响因子：
4.4
通讯作者：
Febo, A
中科院分区：
文献类型：
--
作者：
Stutz, J;Kim, ES;Febo, A
亚硝酸，MONO，是污染大气中OH自由基的来源。虽然对HONO的大气化学性质有了定性的了解，但没有太多的定量信息。由HONO光解产生的OH的大小取决于其吸收截面的光谱;因此sigma（HONO）（lambda）的知识是必不可少的。利用差分光学吸收光谱法（DOAS）对大气中的HONO进行检测时，需要得到HONO的微分截面σ ′（HONO）（λ）谱。在这里，我们提出了测量的HONO紫外-可见吸收截面的光谱分辨率优于0.1 nm和高信噪比。吸收截面的最大值为σ（HONO）（354 nm）=（5.19 +/- 0.26）× 10（-19）cm（2），与文献数据吻合较好。然而，计算的基础上，从这项工作的数据和文献数据显示，类似的15%的不确定性仍然为HONO光解率。在意大利米兰的DOAS测量中采用了新的sigma（HONO）（lambda）。
Nitrous acid, MONO, is a source of OH radicals in the polluted atmosphere. Although the atmospheric chemistry of HONO is qualitatively understood, not much quantitative information exists. The magnitude of the OH production by HONO photolysis depends on the spectrum of its absorption cross sections; therefore the knowledge of sigma(HONO)(lambda) is essential. The spectrum of the differential cross sections sigma'(HONO)(lambda) is needed to detect HONO in the atmosphere by differential optical absorption spectroscopy (DOAS). Here we present measurements of the HONO UV-visible absorption cross sections with a spectral resolution better than 0.1 nm and a high signal-to-noise ratio. The maximum value of the absorption cross sections is sigma(HONO)(354 nm) = (5.19 +/- 0.26) x 10(-19) cm(2) and agrees well with literature data. Nevertheless, calculations based on data from this work and on literature data reveal that an uncertainty of similar to 15% remains for the HONO photolysis rates. The new sigma(HONO)(lambda) has been employed in DOAS measurements in Milan, Italy.