Bones D L, Gerding M, Höffner J, Martín Juan Carlos Gómez, Plane J M C
School of Chemistry University of Leeds Leeds UK.
Leibniz Institute of Atmospheric Physics Rostock University Kühlungsborn Germany.
Geophys Res Lett. 2016 Dec 28;43(24):12333-12339. doi: 10.1002/2016GL071755. Epub 2016 Dec 29.
The dissociative recombination of CaO ions with electrons has been studied in a flowing afterglow reactor. CaO was generated by the pulsed laser ablation of a Ca target, followed by entrainment in an Ar ion/electron plasma. A kinetic model describing the gas-phase chemistry and diffusion to the reactor walls was fitted to the experimental data, yielding a rate coefficient of (3.0 ± 1.0) × 10 cm molecule s at 295 K. This result has two atmospheric implications. First, the surprising observation that the Ca/Fe ratio is ~8 times larger than Ca/Fe between 90 and 100 km in the atmosphere can now be explained quantitatively by the known ion-molecule chemistry of these two metals. Second, the rate of neutralization of Ca ions in a descending sporadic layer is fast enough to explain the often explosive growth of sporadic neutral Ca layers.
在流动余辉反应器中研究了CaO离子与电子的离解复合。通过脉冲激光烧蚀Ca靶产生CaO，然后将其夹带在Ar离子/电子等离子体中。将描述气相化学和向反应器壁扩散的动力学模型与实验数据拟合，在295K时得到速率系数为(3.0±1.0)×10cm³分子⁻¹s⁻¹。该结果有两个大气方面的意义。首先，大气中90至100公里处Ca/Fe比约比Ca/Fe大8倍这一惊人观测结果，现在可以通过这两种金属已知的离子 - 分子化学进行定量解释。其次，在下降的偶发层中Ca离子的中和速率足够快，足以解释偶发中性Ca层经常出现的爆发性增长。
