Laboratory Study of O(1S) Formation Process in the Photolysis of O3 and its Atmospheric Implications
Laboratory Study of O(1S) Formation Process in the Photolysis of O3 and its Atmospheric Implications
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DOI：
10.1007/s10874-006-0597-3
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发表时间：
2006-03
影响因子：
2
通讯作者：
T. Nakayama;Kenshi Takahashi;Y. Matsumi;H. Fujiwara
中科院分区：
文献类型：
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作者：
T. Nakayama;Kenshi Takahashi;Y. Matsumi;H. Fujiwara
利用真空紫外激光诱导荧光光谱(VUV-LIF)高灵敏度检测O(1S)原子的技术，研究了O(1S)的紫外光解离O(1S)的过程。测得臭氧在2 15和2 2 0 nm处光解生成O(1S)的量子产率分别为(1.4±0.4)×10−4和(5±3)×10−5。根据热化学的考虑，O(1S)的生成归因于O(1S)+O2(X3Σg−)的自旋禁忌过程。对O(1s)在193 nm处光解产生的O(1s)的多普勒分布的分析也表明，O(1s)原子是由自旋禁忌过程产生的。在193 nm处N2O和H_2O_2的光解中，没有检测到O(1S)原子的可分辨信号。在波长193 nm处，N2O和H_2O_2光解产生O(1S)的量子产率上限分别为8×10−5和3×10−5。利用实验结果，估算了O(1S)光解生成O(1S)对O(1S)+H2O反应生成大气OH自由基的影响。计算结果表明，在中纬30公里高度，O(1S)+H2O反应对氢气生成速率的贡献是O(1D)+H2O反应贡献的∼2%。文中还讨论了本实验室实验结果对557.7 nm的O(1s)地面气辉的影响。
A high-sensitive technique to detect O(1S) atoms using vacuum ultraviolet laser-induced fluorescence (VUV-LIF) spectroscopy has been applied to study the O(1S) production process from the UV photodissociation of O3, N2O, and H2O2. The quantum yields for O(1S) formation from O3photolysis at 215 and 220 nm are determined to be (1.4 ± 0.4) × 10−4and (5 ± 3) × 10−5, respectively. Based on thermochemical considerations, the O(1S) formation from O3photolysis at 215 and 220 nm is attributed to a spin-forbidden process of O(1S)+O2(X3Σg−). Analysis of the Doppler profile of O(1S) produced from O3photolysis at 193 nm also indicates that the O(1S) atoms are produced from the spin-forbidden process. In the photolysis of N2O and H2O2at 193 nm, no discernible signal of O(1S) atoms has been detected. The upper limit values of the quantum yields for O(1S) production from N2O and H2O2photolysis at 193 nm are estimated to be 8 × 10−5and 3 × 10−5, respectively. Using the experimental results, the impact of the O(1S) formation from O3photolysis on the atmospheric OH radical formation through the reaction of O(1S)+H2O has been estimated. The calculated results show that the contribution of the O(1S)+H2O reaction to the OH production rate is ∼2% of that of the O(1D)+H2O reaction at 30 km altitude in mid-latitude. Implications of the present laboratory experimental results for the terrestrial airglow of O(1S) at 557.7 nm have also been discussed.