Koop T, Carslaw KS
Max Planck Institute for Chemistry, Postfach 3060, 55020 Mainz, Germany.
Science. 1996 Jun 14;272(5268):1638-41. doi: 10.1126/science.272.5268.1638.
Polar stratospheric clouds (PSCs) are important for the chemical activation of chlorine compounds and subsequent ozone depletion. Solid PSCs can form on sulfuric acid tetrahydrate (SAT) (H2SO4·4H2O) nuclei, but recent laboratory experiments have shown that PSC nucleation on SAT is strongly hindered. A PSC formation mechanism is proposed in which SAT particles melt upon cooling in the presence of HNO3 to form liquid HNO3-H2SO4-H2O droplets 2 to 3 kelvin above the ice frost point. This mechanism offers a PSC formation temperature that is defined by the ambient conditions and sets a temperature limit below which PSCs should form.
极地平流层云（PSCs）对于氯化合物的化学活化以及随后的臭氧消耗至关重要。固态极地平流层云可以在四水合硫酸（SAT）（H2SO4·4H2O）核上形成，但最近的实验室实验表明，极地平流层云在SAT上的成核受到强烈阻碍。本文提出了一种极地平流层云形成机制，即在硝酸存在下冷却时，SAT颗粒会融化形成液态HNO3-H2SO4-H2O液滴，其温度比霜点高2至3开尔文。该机制提供了一个由环境条件定义的极地平流层云形成温度，并设定了一个温度下限，低于该温度极地平流层云应该形成。
