New Photodissociation Processes in Ozone and Their Implications for Stratospheric Chemistry

9528086 休斯顿 该项目将有助于了解高层大气中臭氧的光分解和形成过程。最近有人提出了在该区域增加臭氧生产的若干新机制。其中之一涉及从臭氧的光解产生振动激发的氧分子，其可以与基态氧分子反应形成臭氧。这个过程的第一步，振动激发氧的生产，已经证明了PI在早期的工作。第二步，臭氧的形成，还没有明确的确定，但是，有间接的证据，从最近的工作。 在这个项目中，产品成像技术将与激光光解相结合。在成像技术中，产生状态选择的反应产物的三维速度分布的“快照”。由此，可以推导出分子氧碎片的内能分布。本项目的目标是：（1）确定臭氧与另一个氧分子反应生成三重态氧的能量阈值（v=26）以上振动态的波长依赖性，（2）研究单重态解离通道中的产物分布。

9528086 Houston This project will contribute to the understanding of ozone photodissociation and formation processes in the upper atmosphere. Several new mechanisms for additional ozone production in this region have been suggested recently. One of them involves the production of vibrationally excited oxygen molecules from the photodissociation of ozone, which could react with ground state oxygen molecules to form ozone. The first step of this process, production of vibrationally excited oxygen, has been demonstrated by the PI in earlier work. The second step, ozone formation, has not been unambiguously identified, however, there is indirect evidence from recent work. In this project, the technique of product imaging will be used in concert with laser photodissociation. In the imaging technique, a "snap-shot" of the three-dimensional velocity distribution of a state-selected reaction product is produced. From this, the internal energy distribution of the molecular oxygen fragment can be deduced. The objectives of this project are: (1) determine the wavelength dependence of the production of triplet oxygen in the vibrational states above the energetic threshold (v=26) for ozone formation via reaction with another oxygen molecule, (2) investigate the product distributions in the singlet dissociation channel.